HK1196671A

HK1196671A - Silicone hydrogel contact lenses with high freezable water content

Info

Publication number: HK1196671A
Application number: HK14110084.0A
Authority: HK
Inventors: 保罗．鸿昌．李; 刘荣华; 史新峰; 刘宇文; 洪叶; 查理．陈; 姚莉; 阿瑟．巴克; 查尔斯．A．弗朗西斯
Original assignee: 库柏维景国际控股公司
Priority date: 2011-02-28
Filing date: 2012-02-23
Publication date: 2014-12-19

Description

Silicone hydrogel contact lenses with high freezable water content

Cross reference to related applications

The present application claims the benefit of prior U.S. provisional patent application No. 61/447,204, filed 2011/2/28, in accordance with the provisions of 35 u.s.c. § 119(e), which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to silicone hydrogel contact lenses and related compositions and methods.

Background

Commercially and clinically, silicone hydrogel contact lenses are a popular replacement for conventional hydrogel contact lenses (i.e., hydrogel contact lenses that do not contain silicone or silicone-containing components). It is believed that the presence of siloxanes in silicone hydrogel contact lens formulations affects the properties of the silicone hydrogel contact lenses obtained therefrom. For example, it is believed that the presence of the silicone component in the contact lens results in a relatively high oxygen transmission rate as compared to conventional hydrogel contact lenses that do not contain the silicone component. In addition, it is believed that the presence of the silicone component increases the likelihood that hydrophobic domains will be present on the lens surface of the silicone hydrogel contact lens as compared to conventional hydrogel contact lenses that do not contain a silicone component. First generation silicone hydrogel contact lenses also provided high levels of oxygen even though the wettability of the lenses tended to be lower than desired. Various techniques have been developed to overcome the problem of hydrophobicity of the surface of silicone hydrogel contact lenses. Based on the popularity of silicone hydrogel contact lenses, there is a continuing need in the art for novel silicone hydrogel contact lenses having both a high equilibrium water content and a wettable lens surface.

Some documents describing silicone hydrogel contact lenses include: US4711943, US5712327, US5760100, US7825170, US6867245, US20060063852, US20070296914, US7572841, US20090299022, US20090234089, and US20100249356, each of which is incorporated herein in its entirety by reference.

Disclosure of Invention

The present invention relates to polymerizable compositions, to silicone hydrogel contact lenses formed by reacting the polymerizable compositions to form polymeric lens bodies (lens bodies), to batches of the silicone hydrogel contact lenses, to packaging of the silicone hydrogel contact lenses, and to methods of making silicone hydrogel contact lenses from the polymerizable compositions.

The water content of hydrogel contact lenses, particularly silicone hydrogel contact lenses, is an important lens property. The water present in the hydrogel polymer matrix may be described as free water, weakly bound water, or strongly bound water. Free water is water present in the polymer matrix and that can be frozen at 0 ℃, weakly bound water is water present in the polymer matrix and that can be frozen at temperatures below 0 ℃, and strongly bound water is water that does not freeze (i.e., is not freezable) during testing using Differential Scanning Calorimetry (DSC). Surprisingly, it has been found that the level of equilibrium freezable water content present in silicone hydrogel lenses is associated with increased lens comfort, and silicone hydrogel contact lens formulations having very high equilibrium freezable water content have been developed. Without wishing to be bound by theory, it is believed that the high equilibrium freezable water content of these lenses can be related to the high equilibrium levels of free and weakly bound water present in these lenses, and that the high equilibrium levels of free and weakly bound water can impart advantageous properties to these lenses, including properties that can result in, for example, increased comfort and reduced corneal dehydration staining as compared to silicone hydrogel contact lenses having lower equilibrium free and weakly bound water contents. In addition to having a high equilibrium freezable water content, the silicone hydrogel contact lenses described herein may also have a relatively high equilibrium content of non-freezable water. In addition, due to the high level of freezable water present in the lenses, the ratio of the percentage of freezable water present to the percentage of non-freezable water in the silicone hydrogel lenses described herein may also be higher. It has been found that lenses having a high equilibrium freezable water content level (alone or in combination with a high non-freezable water content level) and comprising a specific ratio of the percentage of freezable water to the percentage of non-freezable water have particularly advantageous properties that positively affect the comfort of the lens wearer when inserting the lens and at a later point in time.

The polymerizable composition of the present invention comprises (a) at least one siloxane monomer and (b) at least one hydrophilic monomer. The at least one siloxane monomer and the at least one hydrophilic monomer are present in the polymerizable composition in amounts such that, when the polymerizable composition is used to form a silicone hydrogel contact lens, the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC).

The polymerizable composition may optionally comprise at least one hydrophobic monomer. The polymerizable composition may optionally comprise at least one crosslinking agent. Optionally, the ingredients in the polymerizable composition can further comprise at least one initiator, or at least one organic diluent, or at least one surfactant, or at least one colorant, or at least one UV absorber, or at least one oxygen scavenger, or at least one chain transfer agent, or a combination thereof.

The polymerizable compositions of the present invention are reacted to form polymeric lens bodies, which are further processed to prepare silicone hydrogel contact lenses. The silicone hydrogel contact lenses have an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by DSC. In one example, the silicone hydrogel contact lens has an equilibrium freezable water content of at least 27% wt/wt or at least 29% wt/wt. In another example, the silicone hydrogel contact lens has an equilibrium freezable water content of 27% to 40% wt/wt when fully hydrated.

The silicone hydrogel contact lenses can also have an equilibrium non-freezable water content of at least 20% wt/wt when fully hydrated, as determined by DSC. In one example, the silicone hydrogel contact lens has an equilibrium non-freezable water content of at least 22% wt/wt, or at least 24% wt/wt, or at least 26% wt/wt. In another example, the silicone hydrogel contact lens has an equilibrium non-freezable water content of 20% wt/wt to 45% wt/wt, or 25% to 45% wt/wt, or 27% to 40% wt/wt.

The silicone hydrogel contact lenses can also have a ratio of equilibrium freezable water (% wt/wt) to equilibrium non-freezable water (% wt/wt) of at least 0.9: 1.0 when fully hydrated. In one example, the ratio can be at least 1.0: 1.0, or greater than 1.0: 1.0. In another example, the ratio can be 1: 1 to 10: 1, or 3: 1 to 7: 1. Silicone hydrogel contact lenses can have particularly advantageous physical properties, including an Equilibrium Water Content (EWC) of about 30% wt/wt to about 70% wt/wt, as determined by gravimetric analysis; or has a tensile modulus of about 0.2MPa to about 0.9MPa, or has a percent energy loss of about 25% to about 45%, or any combination thereof.

The polymerizable compositions of the present invention may comprise a single siloxane monomer, or may comprise a plurality of siloxane monomers present as the siloxane component. In one example, the silicone component can comprise a first silicone monomer and a second silicone monomer. The first siloxane monomer can be a siloxane monomer having a number average molecular weight of 400 daltons to 700 daltons. The second siloxane monomer can be a siloxane monomer having a number average molecular weight of greater than 7,000 daltons or a number average molecular weight of from 7,000 daltons to 20,000 daltons.

In one example of the polymerizable composition, the at least one siloxane monomer can comprise a monofunctional siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group. In a specific example, the siloxane monomer may be a siloxane monomer represented by formula (3), wherein is a monofunctional siloxane monomer of formula (3), wherein m in formula (3) is 4, n in formula (3) is 1, and R in formula (3)¹Is butyl, and each R in formula (3)²Independently a hydrogen atom or a methyl group.

In another example of the polymerizable composition, the at least one siloxane monomer can comprise a difunctional siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration. In a specific example, the siloxane monomer of formula (4) may be a siloxane monomer represented by formula (4), which is a bifunctional siloxane monomer, wherein m in formula (4) is 0, n in formula (4) is an integer of 5 to 15, a is an integer of 65 to 90, b is an integer of 1 to 10, and R in formula (4)₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms.

In another example, the polymerizable composition can comprise a first siloxane monomer that is a monofunctional siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3) ²Independently a hydrogen atom or a methyl group; and a second siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100;a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration.

In yet another example, the polymerizable composition can comprise a first siloxane monomer that is a monofunctional siloxane monomer represented by formula (3):

wherein m in formula (3) is 4, n in formula (3) is 1, R in formula (3)¹Is butyl, and each R in formula (3)²Independently a hydrogen atom or a methyl group; and a second siloxane monomer represented by formula (4):

wherein m in formula (4) is 0, n in formula (4) is an integer of 5 to 15, a is an integer of 65 to 90, b is an integer of 1 to 10, R in formula (4)₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms.

A batch of silicone hydrogel contact lenses may be prepared by preparing a plurality of silicone hydrogel contact lenses. In one example, the batch of silicone hydrogel contact lenses comprises a plurality of silicone hydrogel contact lenses formed from polymerized lens bodies that are the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; wherein the batch of silicone hydrogel contact lenses, when fully hydrated, has an average equilibrium freezable water content of at least 25% wt/wt or 27% to 40% as determined by Differential Scanning Calorimetry (DSC).

The batch of contact lenses can have properties that make them particularly advantageous for use as contact lensesLens properties of contact lenses. For example, based on an average of the values determined for at least 20 individual lenses in the batch, the batch of silicone hydrogel contact lenses, when fully hydrated, has at least one property selected from the group consisting of: an average Equilibrium Water Content (EWC) of about 30% wt/wt to about 70% wt/wt, or an average tensile modulus of about 0.2MPa to about 0.9MPa, or an average percent energy loss of about 25% to about 45%, or an average Dk of at least 55 barrers, or less than about 8 x 10^-3mm²An average ion current per min (ionoflox), or an average captive bubble dynamic advancing contact angle of less than 120 degrees, or an average captive bubble static contact angle of less than 70 degrees, or an average wet extractable component content of less than 10% wt/wt, or an average dry extractable component content of less than 20% wt/wt, or any combination thereof.

The present invention also relates to silicone hydrogel contact lens packages. The silicone hydrogel contact lens package can comprise: a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; a packaging solution comprising a lens hydrating agent; and a contact lens package base member having a cavity configured to receive a contact lens body and a packaging solution; and a seal attached to the base member, the seal configured to maintain the silicone hydrogel contact lens and the packaging solution under sterile conditions for a duration of time equivalent to a room temperature shelf life of the contact lens; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt or 27% to 40% when fully hydrated, as determined by Differential Scanning Calorimetry (DSC).

The present invention also relates to methods of manufacturing silicone hydrogel contact lenses. The method can comprise providing a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; and polymerizing the polymerizable composition to form a polymerized lens body, which is then treated to form the silicone hydrogel contact lens. The silicone hydrogel contact lenses have an equilibrium freezable water content of at least 25% wt/wt or 27% to 40% when fully hydrated, as determined by DSC. In one example, polymerizing the polymerizable composition can be carried out in a contact lens mold assembly to form a polymeric lens body. The method can further comprise the step of contacting the polymeric contact lens body with a cleaning solution to remove extractable material from the polymeric contact lens body. The method can also further comprise the step of packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package.

In one example, the polymerizing step can include polymerizing the polymerizable composition in a contact lens mold assembly having a molding surface formed from a non-polar thermoplastic polymer to form a polymeric lens body. Alternatively, the polymerizing step can comprise polymerizing the polymerizable composition in a contact lens mold assembly having a molding surface formed from a non-polar thermoplastic polymer to form a polymeric lens body.

In one example, the contacting step can comprise contacting the polymerized contact lens body with a wash solution that is free of volatile organic solvents. In another example, the contacting step can comprise contacting the polymeric contact lens body with a wash solution comprising a volatile organic solvent. In yet another example, the method can be a method that does not contact the polymeric lens body and the silicone hydrogel contact lens comprising the polymeric lens body with a volatile organic solvent during the manufacturing process.

In another example, the method can comprise the step of demolding the polymeric lens body, or the step of delensing the polymeric lens body, or both the step of demolding and delensing the polymeric lens body from a mold assembly used for its cast molding. In particular examples, the demolding and delensing steps can include mechanical demolding and delensing steps, i.e., demolding and delensing steps that do not involve contacting the polymeric lens body with a liquid during demolding and delensing.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed.

Detailed Description

As described herein, silicone hydrogel contact lenses are formed from a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer. The amount of ingredients present in the polymerizable composition should be such that, when polymerized and processed to form a silicone hydrogel contact lens, the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt, for example, an equilibrium freezable water content of 27% to 40% wt/wt, as determined by DSC. The hydrogel contact lenses of the invention comprise or consist of a hydrated lens body comprising a polymeric component and a liquid component.

In one example, the silicone hydrogel contact lens is a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Freezable water% wt/wt ═ [ (peak area of free and weakly bound water)/Y ] × 100(a),

wherein F is the calorific value of pure water in melting and is expressed by J/g.

The polymeric component comprises units of at least one siloxane monomer and units of at least one hydrophilic monomer. By hydrophilic monomer is understood a non-silicone polymerizable component having only one polymerizable functional group present in its molecular structure. The at least one hydrophilic monomer is understood to comprise a single hydrophilic monomer, or to comprise a hydrophilic monomer component consisting of two or more hydrophilic monomers. The at least one siloxane monomer is understood to comprise a single siloxane monomer, or to comprise a siloxane monomer component consisting of two or more siloxane monomers. It is thus understood that the polymeric component is the reaction product of a polymerizable composition comprising one or more siloxane monomers and one or more hydrophilic monomers, and may optionally include units of any other polymerizable ingredients present in the polymerizable composition.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the at least one hydrophilic monomer is present in the polymerizable composition in an amount of 30 parts by weight (unit parts by weight) to 60 parts by weight, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein F is the calorific value of pure water in melting and is expressed by J/g. In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the at least one hydrophilic monomer comprises a hydrophilic amide monomer having one N-vinyl group, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the at least one hydrophilic monomer comprises a hydrophilic amide monomer having one N-vinyl group, and the hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 unit parts by weight to 60 unit parts by weight, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The ingredients in the polymerizable composition may optionally further comprise other monomers or macromers or prepolymers or polymers or combinations thereof. The other monomer or macromer or prepolymer or polymer or combination thereof may be a silicon-containing compound or may be a non-silicon-containing compound. As used herein, a silicon-free compound is understood to be a compound that does not have a silicon atom in its molecular structure. The other ingredients in the polymerizable composition can be polymerizable or non-polymerizable ingredients. Polymerizable ingredients as used herein are understood to be compounds having a polymerizable double bond as part of their molecular structure. Thus, the non-polymerizable component does not have a polymerizable double bond as part of its molecular structure. When present in the polymerizable composition, the at least one crosslinker and the at least one hydrophobic monomer of the polymerizable composition are understood to be non-silicon containing polymerizable ingredients. As used herein, at least one crosslinker can be understood to comprise a single crosslinker, or to comprise a crosslinker component consisting of two or more crosslinkers. Similarly, the optional at least one hydrophobic monomer may be understood to comprise a single hydrophobic monomer, or to comprise a hydrophobic monomer component consisting of two or more hydrophobic monomers. Additionally, the polymerizable composition may optionally include at least one initiator, or at least one organic diluent, or at least one surfactant, or at least one oxygen scavenger, or at least one colorant, or at least one UV absorber, or at least one chain transfer agent, or any combination thereof. The optional at least one initiator, at least one organic diluent, at least one surfactant, at least one oxygen scavenger, at least one colorant, at least one UV absorber, or at least one oxygen scavenger, or at least one chain transfer agent is understood to be a silicon-free component and may be a non-polymerizable component or a polymerizable component (i.e., a component having a polymerizable functional group as part of its molecular structure).

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; (b) at least one hydrophilic monomer; and (c) at least one cross-linking agent; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; (b) at least one hydrophilic monomer; and (c) at least one vinyl-containing crosslinking agent; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The combination of the polymeric component and the liquid component is present as a hydrated lens body suitable for placement on a human eye. The hydrated lens body has an overall convex anterior surface and an overall concave posterior surface, and an Equilibrium Water Content (EWC) of greater than 10% (weight/weight, wt/wt). Thus, the present contact lenses can be understood as soft contact lenses, which as used herein refers to contact lenses that can fold upon themselves without breaking when fully hydrated.

As understood in the industry, a daily disposable contact lens is an unworn contact lens that is removed from a sealed sterile package (original package) made by the contact lens manufacturer, placed on a person's eye, and at the end of the day, the lens that the person has worn is removed and discarded. Typically, the lenses of a daily disposable contact lens are worn for a duration of 8 to 14 hours and are then discarded after being worn. The daily disposable lens is not washed or exposed to a wash solution prior to placement on the eye because it is sterile prior to opening the package. Daily disposable silicone hydrogel contact lenses are disposable silicone hydrogel contact lenses that are replaced daily. In contrast, non-daily disposable contact lenses are disposable contact lenses that are replaced less frequently than daily (e.g., weekly, biweekly, or monthly). The non-daily disposable contact lenses are removed from the eye and periodically rinsed with a rinsing solution, or worn continuously without removal from the eye. The contact lenses of the invention can be daily-throw contact lenses or non-daily-throw contact lenses. The present invention relates to polymerizable compositions comprising at least one siloxane monomer and at least one hydrophilic monomer, polymerized lens bodies that are reaction products of the polymerizable compositions, silicone hydrogel contact lenses comprising the polymerized lens bodies in hydrated form, packages comprising the silicone hydrogel contact lenses and a packaging solution in a sealed package, and methods of making the silicone hydrogel contact lenses.

The water content of hydrogel contact lenses, particularly silicone hydrogel contact lenses, is an important lens property. Historically, obtaining silicone hydrogel contact lenses with high water content has been challenging due to the hydrophobic nature of the siloxane monomers. The water present in the hydrogel polymer matrix may be described as free water, weakly bound water, or strongly bound water. Free water is water present in the polymer matrix and that can be frozen at 0 ℃, weakly bound water is water present in the polymer matrix and that can be frozen at temperatures below 0 ℃, and strongly bound water is water that does not freeze (i.e., is not freezable) during testing using Differential Scanning Calorimetry (DSC). Silicone hydrogel contact lens formulations have been developed that not only have a high Equilibrium Water Content (EWC), but they also have a high equilibrium freezable water content. Without wishing to be bound by theory, it is believed that the high equilibrium freezable water content of these lenses is related to the high equilibrium levels of free and weakly bound water present in these lenses, and that the high equilibrium levels of free and weakly bound water can have a positive impact on the clinical properties of the lenses, e.g., increased comfort and reduced corneal dehydration staining as compared to silicone hydrogel contact lenses having lower equilibrium free and weakly bound water contents. In addition to having a high equilibrium freezable water content as determined by DSC, the silicone hydrogel contact lenses described herein may also have a relatively high equilibrium content of non-freezable water as determined by DSC. Additionally, due to the high level of freezable water present in the lenses, the ratio of the percentage of freezable water present to the percentage of non-freezable water present in the silicone hydrogel lenses described herein may also be higher.

The silicone hydrogel contact lenses of the invention have an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by DSC. In one example, the silicone hydrogel contact lens can have an equilibrium freezable water content of at least 27% wt/wt, or at least 29% wt/wt, or at least 30% wt/wt. The silicone hydrogel contact lenses of the invention, when fully hydrated, can have an equilibrium freezable water content of 25% wt/wt to 45% wt/wt or 27% to 40% wt/wt.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of from 27% wt/wt to 40% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The silicone hydrogel contact lens, when fully hydrated, can have an equilibrium non-freezable water content of at least 20% wt/wt. In one example, the silicone hydrogel contact lens can have an equilibrium non-freezable water content of at least 22% wt/wt, or at least 24% wt/wt, or at least 26% wt/wt. The silicone hydrogel contact lens, when fully hydrated, can have an equilibrium non-freezable water content of 20% wt/wt to 40% wt/wt, or 24% wt/wt to 40% wt/wt, or 26% wt/wt to 40% wt/wt.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein F is the heat value of pure water melting and is expressed by J/g; and wherein the silicone hydrogel contact lens has an equilibrium non-freezable water content of at least 25% wt/wt when fully hydrated, as determined by DSC, and calculated using equation (B):

Non-freezable water% wt/wt ═ EWC (% wt/wt) -freezable water content (% wt/wt) (B),

wherein EWC is the equilibrium water content of the lens and said freezable water content of the lens is determined using equation (a).

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of 25% wt/wt to 40% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein F is the heat value of pure water melting and is expressed by J/g; and wherein the silicone hydrogel contact lens, when fully hydrated, has an equilibrium non-freezable water content of 25% wt/wt to 40% wt/wt as determined by DSC and calculated using equation (B):

The ratio of the percentage of freezable water to the percentage of non-freezable water present in a fully hydrated silicone hydrogel contact lens can be calculated by dividing the% wt/wt of freezable water by the% wt/wt of non-freezable water. The ratio of the percentage of freezable water to the percentage of non-freezable water for the silicone hydrogel contact lenses described herein can be at least 0.9: 1.0, or at least 1.0: 1.0, or greater than 1.0: 1.0. The ratio of the equilibrium freezable water content to the equilibrium non-freezable water content may be at least 3: 1, or may be from 3: 1 to 10: 1.

wherein F is the heat value of pure water melting and is expressed by J/g; and wherein the silicone hydrogel contact lens has an equilibrium non-freezable water content when fully hydrated as determined by DSC, and is calculated using equation (B):

wherein EWC is the equilibrium water content of the lens and the freezable water content of the lens is determined using equation (a); wherein the ratio of the equilibrium freezable water content to the equilibrium non-freezable water content of the contact lens is at least 3: 1.

The DSC method for determining the equilibrium freezable water content and equilibrium non-freezable water content of a silicone hydrogel contact lens may be a method in which a sample of a fully hydrated silicone hydrogel contact lens equilibrated in deionized water is scanned at a rate of, for example, about 5 ℃/minute over a temperature range of about-40 ℃ to about 30 ℃. Using the method, the percentage of frozen water can be calculated based on the peak areas of the peaks of free and weakly bound water as determined by DSC. The percentage of freezable water disclosed herein is calculated using equation (a):

The F value may be the heating value of pure water melting reported in the literature, or may be the heating value of melting as determined in experiments using the same equipment used to test the samples.

The percentage of unfrozen water was then calculated using the percentage of freezable water, using the Equilibrium Water Content (EWC) determined for the lens, using equation (B):

non-freezable water% wt/wt ═ EWC (% wt/wt) -freezable water content (% wt/wt) (B).

Additionally, the silicone hydrogel contact lenses of the present invention can have other properties that make them ophthalmically acceptable and/or particularly advantageous for use as contact lenses.

In one example, a silicone hydrogel contact lens can have an Equilibrium Water Content (EWC) of about 30% to about 70% when fully hydrated. For example, a contact lens may have an EWC of about 45% to about 65%, or about 50% to about 63%, or about 50% to about 67%, or about 55% to about 65% by weight when fully hydrated. Methods of determining EWC are known to those skilled in the art and can be based on the weight loss of the lens during the drying process.

The silicone hydrogel contact lenses of the invention, when fully hydrated, can have an average tensile modulus of about 0.20MPa to about 0.90 MPa. For example, the average modulus can be from about 0.30MPa to about 0.80MPa, or from about 0.40MPa to about 0.75MPa, or from about 0.50MPa to about 0.70 MPa.

The modulus of a contact lens or lens body as used herein is understood to mean the tensile modulus, also known as Young's modulus. Which is a measure of the stiffness of an elastic material. Tensile modulus can be measured using a method that meets ANSI Z80.20 standards. In one example, the tensile modulus may be measured using an Instron model 3342 or 3343 mechanical testing system.

The silicone hydrogel contact lenses of the invention can have an average percent energy loss of about 25% to about 40% when fully hydrated. For example, the average percent energy loss may be from about 27% to about 40%, or may be from about 30% to about 37%.

Percent energy loss, as used herein, is a measure of the energy lost as heat when a cycle of energy loading and energy release is applied to a viscoelastic material. The percent energy loss can be determined using a variety of methods known to those skilled in the art. For example, the force involved in stretching a sample to 100% strain at a constant rate, and then returning it to 0%, can be determined and used to calculate the percent energy loss of the material.

wherein F is the heat value of pure water melting and is expressed by J/g; and wherein the contact lens has an Equilibrium Water Content (EWC) of about 30% wt/wt to about 70% wt/wt as determined by gravimetric analysis; or has a tensile modulus of about 0.2MPa to about 0.9MPa, or has a percent energy loss of about 25% to about 45%, or any combination thereof.

The contact lenses of the invention may have an oxygen permeability (or Dk) of at least 55 barrers (Dk ≧ 55 barrers), or an oxygen permeability of at least 60 barrers (Dk ≧ 60 barrers), or an oxygen permeability of at least 65 barrers (Dk ≧ 65 barrers). The lens may have an oxygen permeability of about 30 to 120, or about 55 to about 135, or about 60 to about 120, or about 65 to about 90, or about 50 to about 75 bara. The present contact lenses may have an oxygen permeability of at least 30 barrers, or at least 40 barrers, or at least 50 barrers. The lens may have an oxygen permeability of 30 to 55, or 35 to 45, bara. Various methods of measuring oxygen permeability are known to those skilled in the art.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an oxygen permeability of 30 to 120 barrers when fully hydrated, and an equilibrium freezable water content of at least 25% wt/wt as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an oxygen permeability of 65 to 90 barrers when fully hydrated, and an equilibrium freezable water content of at least 25% wt/wt as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an oxygen permeability of 50 to 75 barrers when fully hydrated, and an equilibrium freezable water content of at least 25% wt/wt as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In yet another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an oxygen permeability of 35 to 75 barrers when fully hydrated, and an equilibrium freezable water content of at least 25% wt/wt as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The invention relates to a contact lensWhen fully hydrated, may have a particle size of less than about 8.0X 10^-3mm²A/min, or less than about 7.0X 10^-3mm²A/min, or less than about 5.0X 10^-3mm²Ion flow/min. Various methods of determining ion current are conventional and known to those skilled in the art.

The present contact lenses may have an oxygen permeability of at least 55 barrers (Dk ≧ 55 barrers), or an EWC of about 30% to about 70%, or a captive bubble dynamic advancing contact angle of less than 90 degrees, or a captive bubble static contact angle of less than 70 degrees, or any combination thereof. In one example, the contact lens may have an oxygen permeability of at least 60 barrers (Dk ≧ 60 barrers), or an EWC of about 35% to about 65%, or a captive bubble dynamic advancing contact angle of less than 70 degrees, or a captive bubble static contact angle of less than 55 degrees, or any combination thereof. In another example, the present contact lenses can have an oxygen permeability of at least 65 barrers, or an EWC of about 45% to about 65%, or a captive bubble dynamic advancing contact angle of less than 70 degrees, or a captive bubble static contact angle of less than 55 degrees, or any combination thereof.

In one example, the present contact lenses have an oxygen permeability of at least 55 barrers, an EWC of about 30% to about 70%, a captive bubble dynamic advancing contact angle of less than 70 degrees, and a captive bubble static contact angle of less than 55 degrees.

In one example, the present contact lenses, when fully hydrated, can have an oxygen permeability of at least 55 barrers (Dk ≧ 55 barrers), a tensile modulus of about 0.2MPa to about 0.9MPa, and a captive bubble dynamic advancing contact angle of less than 70 degrees, and a captive bubble static contact angle of less than 55 degrees.

Various methods of measuring contact angle are known to those skilled in the art, including bubble trapping. The contact angle may be a static or dynamic contact angle. The silicone hydrogel contact lenses of the invention can have a captive bubble dynamic advancing contact angle of less than 120 degrees, for example, less than 90 degrees when fully hydrated, less than 80 degrees when fully hydrated, less than 70 degrees when fully hydrated, or less than 65 degrees when fully hydrated, or less than 60 degrees when fully hydrated, or less than 50 degrees when fully hydrated, or from 0 to 90 degrees when fully hydrated. The silicone hydrogel contact lenses of the invention can have a bubble-trapping static contact angle of less than 70 degrees when fully hydrated, or less than 60 degrees when fully hydrated, or less than 55 degrees when fully hydrated, or less than 50 degrees when fully hydrated, or less than 45 degrees when fully hydrated, or from 0 to 70 degrees when fully hydrated.

wherein F is the heat value of pure water melting and is expressed by J/g; and wherein the contact lens, when fully hydrated, has a captive bubble dynamic advancing contact angle of less than 90 degrees, or a captive bubble static contact angle of less than 70 degrees, or both.

In one example, the present contact lenses can have a wet extractable component. The wet extractable component was determined based on the weight loss of the contact lens during methanol extraction, which had been fully hydrated and sterilized prior to drying and extraction testing. The wet extractable component can comprise unreacted or partially reacted polymerizable ingredients of the polymerizable composition. For lenses formed from polymerizable compositions comprising non-polymerizable ingredients, the wet extractable component is comprised of an organic solvent extractable material that remains in the lens body after the lens body has been completely treated to form a sterilized contact lens. For lenses that are extracted in either an extraction solution containing a volatile organic solvent or an extraction solution without an organic solvent during manufacture, in most cases, substantially all of the non-polymerizable components have been removed from the lens body, and thus the wet extractable component can consist essentially of extractable components formed from the reactive polymerizable components (i.e., unreacted polymerizable components and partially reacted polymerizable components) in the polymerizable composition. In lenses prepared from polymerizable compositions without diluents, the wet extractable component can be present in the contact lens in an amount of from about 1% wt/wt to about 15% wt/wt, or from about 2% wt/wt to about 10% wt/wt, or from about 3% wt/wt to about 8% wt/wt, based on the dry weight of the lens body prior to the extraction test. In lenses made from polymerizable compositions comprising diluents, the wet extractable component can consist of a portion of the diluent and unreacted and partially reacted polymerizable ingredients, and can be present in the contact lens in an amount of from about 1% wt/wt to about 20% wt/wt, or from about 2% wt/wt to about 15% wt/wt, or from about 3% wt/wt to about 10% wt/wt of the lens based on the dry weight of the lens body prior to the extraction test.

In one example, the present contact lenses have a dry extractable component. The dry extractable component is determined based on the weight loss of the polymeric lens body during methanol extraction, which has not been washed, extracted (as part of the manufacturing process), hydrated, or sterilized prior to drying and extraction testing. The dry extractable component can comprise unreacted or partially reacted polymerizable ingredients of the polymerizable composition. Where optional non-polymerizable ingredients such as diluents are present in the polymerizable composition, the dry extractable component may further comprise non-polymerizable ingredients.

In lenses made from a diluent-free polymerizable composition, the dry extractable component of the lens consists essentially of the dry extractable component contributed by the polymerizable ingredients in the polymerizable composition (i.e., unreacted or partially reacted polymerizable ingredients), and may also include a small amount (e.g., less than 3% wt/wt) of dry extractable material contributed by optional non-polymerizable components (e.g., colorants, oxygen scavengers, etc.) present in the polymerizable composition. In lenses made from polymerizable compositions without diluents, the dry extractable component can be present in the polymerized lens body in an amount from about 1% wt/wt to about 30% wt/wt, or from about 2% wt/wt to about 25% wt/wt, or from about 3% wt/wt to about 20% wt/wt, or from about 4% wt/wt to about 15% wt/wt, or from 2% wt/wt to less than 10% wt/wt, based on the dry weight of the lens body prior to the extraction test.

In lenses made from polymerizable compositions that contain significant amounts (e.g., greater than 3% wt/wt) of optional non-polymerizable ingredients such as diluents, the dry extractable component is made up of extractable material contributed by reactive ingredients in the polymerizable composition as well as extractable components contributed by non-polymerizable ingredients in the polymerizable composition. The total amount of reactive and non-polymerizable components contributing dry extractable components present in the contact lens can be comprised of an amount of from about 1% wt/wt to about 75% wt/wt, or from about 2% wt/wt to about 50% wt/wt, or from about 3% wt/wt to about 40% wt/wt, or from about 4% wt/wt to about 20% wt/wt, or from about 5% to about 10% of the lens based on the dry weight of the polymeric lens body prior to the extraction test. The total amount of dry extractable components contributed by the polymerizable ingredients (i.e., unreacted or partially reacted polymerizable ingredients) can be in an amount of from about 1% wt/wt to about 30% wt/wt, or from about 2% wt/wt to about 25% wt/wt, or from about 3% wt/wt to about 20% wt/wt, or from about 4% wt/wt to about 15% wt/wt, or from 2% wt/wt to less than 10% wt/wt of the lens body based on the dry weight of the lens body prior to the extraction test.

In one example, the present invention relates to polymerizable compositions comprising at least one siloxane monomer and at least one hydrophilic monomer, and thus the polymerized lens body formed from such polymerizable compositions is formed from polymerized units of at least one siloxane monomer and polymerized units of at least one hydrophilic monomer.

As used herein, the hydrophilic monomer of the polymerizable composition is understood to be a silicon-free hydrophilic monomer and thus is different from a siloxane monomer. The hydrophilicity or hydrophobicity of the monomers (including silicon-containing and silicon-free monomers) can be determined using conventional techniques (e.g., based on the water solubility of the monomers). For the purposes of the present invention, hydrophilic monomers are monomers which are significantly soluble in aqueous solutions at room temperature (e.g., about 20 ℃ to 25 ℃). For example, a hydrophilic monomer can be understood to be any monomer that is significantly completely soluble in 1 liter of water at 20 ℃ for 50 grams or more than 50 grams of monomer (i.e., the monomer can be dissolved in water at a level of at least 5% wt/wt), as determined using standard shake flask methods known to those skilled in the art. Hydrophobic monomers as used herein are the following monomers: are significantly insoluble in aqueous solutions at room temperature, such that there are multiple separate visually discernible phases in the aqueous solution, or such that the aqueous solution appears cloudy and separates into two distinct phases over time upon standing at room temperature. By way of example, a hydrophobic monomer is understood to be any monomer that is significantly incapable of completely dissolving 50 grams of monomer in 1 liter of water at 20 ℃ (i.e., the monomer is dissolved in water at a level of less than 5% wt/wt).

Examples of hydrophilic monomers that can be included in the polymerizable compositions of the present invention can include, for example, N-Dimethylacrylamide (DMA), or 2-hydroxyethyl acrylate, or 2-hydroxyethyl methacrylate (HEMA), or 2-hydroxypropyl methacrylate, or 2-hydroxybutyl methacrylate (HOB), or 2-hydroxybutyl acrylate, or 4-hydroxybutyl acrylate glycerol methacrylate, or 2-hydroxyethyl methacrylamide, or polyethylene glycol monomethacrylate, or methacrylic acid, or acrylic acid, or any combination thereof. However, in one example, the polymerizable composition can be free of N, N-Dimethylacrylamide (DMA).

In one example, the hydrophilic monomer or hydrophilic monomer component can comprise or consist of a vinyl-containing monomer. Examples of hydrophilic vinyl-containing monomers that can be provided in the polymerizable composition include, but are not limited to, N-vinyl formamide, or N-vinyl acetamide, or N-vinyl-N-ethyl acetamide, or N-vinyl isopropylamide, or N-vinyl-N-methyl acetamide (VMA), or N-vinyl pyrrolidone (NVP), or N-vinyl caprolactam, or N-vinyl-N-ethyl formamide, or N-vinyl formamide, or N-2-hydroxyethyl vinyl carbamate, or N-carboxy-beta-alanine N-vinyl ester, 1, 4-Butanediol Vinyl Ether (BVE), or Ethylene Glycol Vinyl Ether (EGVE), or diethylene glycol vinyl ether (DEGVE), Or any combination thereof.

In another example, the hydrophilic monomer or hydrophilic monomer component in the polymerizable composition can comprise or consist of a hydrophilic amide monomer. The hydrophilic amide monomer may be a hydrophilic amide monomer having one N-vinyl group, such as N-vinyl formamide, or N-vinyl acetamide, or N-vinyl-N-ethyl acetamide, or N-vinyl isopropylamide, or N-vinyl-N-methyl acetamide (VMA), or N-vinyl pyrrolidone (NVP), or N-vinyl caprolactam, or any combination thereof. In one example, the hydrophilic monomer or hydrophilic monomer component comprises N-vinyl-N-methylacetamide (VMA). For example, the hydrophilic monomer or monomer component can comprise or consist of VMA. In one particular example, the hydrophilic monomer can be VMA.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic amide monomer having an N-vinyl group; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In yet another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic amide monomer having one N-vinyl group; wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in an amount of 30 to 60 parts by weight of a unit in a polymerizable composition, the polymerizable composition being free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, the hydrophilic vinyl-containing monomer or monomer component can comprise or consist of a vinyl ether-containing monomer. Examples of vinyl ether-containing monomers include, but are not limited to, 1, 4-Butanediol Vinyl Ether (BVE), or Ethylene Glycol Vinyl Ether (EGVE), or diethylene glycol vinyl ether (DEGVE), or any combination thereof. In one example, the hydrophilic monomer component comprises or consists of BVE. In another example, the hydrophilic monomer component comprises or consists of EGVE. In yet another example, the hydrophilic vinyl component comprises or consists of DEGVE.

In yet another example, the hydrophilic vinyl-containing monomer component can comprise or consist of a combination of a first hydrophilic monomer or monomer component and a second hydrophilic monomer or hydrophilic monomer component. In one example, the first hydrophilic monomer has a different polymerizable functional group than the second hydrophilic monomer. In another example, each monomer of the first hydrophilic monomer has a different polymerizable functional group than the second hydrophilic monomer. In another example, the first hydrophilic monomer has a polymerizable functional group different from each monomer of the second hydrophilic monomer component. In yet another example, each monomer of the first hydrophilic monomer component has a different polymerizable functional group than each monomer of the second hydrophilic monomer component.

For example, where the first hydrophilic monomer or monomer component comprises or consists of one or more amide-containing monomers, the second hydrophilic monomer or monomer component can comprise or consist of one or more amide-free monomers (i.e., one or more monomers each of which does not have an amide functional group as part of its molecular structure). As another example, when the first hydrophilic monomer or monomer component comprises or consists of one or more vinyl-containing monomers, the second hydrophilic monomer or monomer component can comprise one or more non-vinyl monomers (i.e., one or more monomers, each of which does not have a vinyl polymerizable functional group as part of its molecular structure). In another example, where the first hydrophilic monomer or monomer component comprises or consists of one or more amide monomers each having an N-vinyl group, the second hydrophilic monomer or monomer component can comprise or consist of one or more amide-free monomers. Where the first hydrophilic monomer or monomer component comprises or consists of one or more acrylate-free monomers (i.e., one or more monomers, each of which does not have an acrylate or methacrylate polymerizable functional group as part of its molecular structure), the second hydrophilic monomer or monomer component can comprise or consist of one or more acrylate-containing monomers or one or more methacrylate-containing monomers or any combination thereof. Where the first hydrophilic monomer or monomer component comprises or consists of one or more vinyl ether-free monomers (i.e., one or more monomers, each of which does not have a vinyl ether polymerizable functional group as part of its molecular structure), the second hydrophilic monomer or monomer component can comprise or consist of one or more vinyl ether-containing monomers. In a particular example, the first hydrophilic monomer or monomer component can comprise or consist of one or more amide-containing monomers each having an N-vinyl group, and the second hydrophilic monomer or monomer component can comprise or consist of one or more vinyl ether-containing monomers.

In one example, where the first hydrophilic monomer or monomer component comprises or consists of a hydrophilic amide-containing monomer having one N-vinyl group, the second hydrophilic monomer or monomer component can comprise or consist of a vinyl ether-containing monomer. In a particular example, the first hydrophilic monomer can comprise VMA, and the second hydrophilic monomer or monomer component can comprise BVE or EGVE or DEGVE, or any combination thereof. The first hydrophilic monomer may comprise VMA and the second hydrophilic monomer may comprise BVE. The first hydrophilic monomer may comprise VMA and the second hydrophilic monomer may comprise EGVE. The first hydrophilic monomer may comprise VMA and the second hydrophilic monomer may comprise DEGVE. The first hydrophilic monomer may comprise VMA, and the second hydrophilic monomer component may comprise EGVE and DEGVE.

Similarly, the first hydrophilic monomer may be VMA, and the second hydrophilic monomer or monomer component may comprise BVE or EGVE or DEGVE, or any combination thereof. The first hydrophilic monomer can be VMA and the second hydrophilic monomer can be BVE. The first hydrophilic monomer may be VMA and the second hydrophilic monomer may be EGVE. The first hydrophilic monomer may comprise VMA and the second hydrophilic monomer may be DEGVE. The first hydrophilic monomer can be VMA and the second hydrophilic monomer component can be a combination of EGVE and DEGVE.

In another example, the silicon-free hydrophilic vinyl-containing monomer can have any molecular weight, such as a molecular weight of less than 400 daltons, or less than 300 daltons, or less than 250 daltons, or less than 200 daltons, or less than 150 daltons, or from about 75 daltons to about 200 daltons.

When a hydrophilic monomer or hydrophilic monomer component is present in the polymerizable composition, the hydrophilic monomer or monomer component can be present in the polymerizable composition in an amount of 30 to 60 unit parts of the polymerizable composition. The hydrophilic monomer or monomer component can be present in the polymerizable composition in a unit weight part of 40 to 55, or 45 to 50. Where the hydrophilic monomer component in the polymerizable composition comprises a first hydrophilic monomer or monomer component and a second hydrophilic monomer or monomer component, the second hydrophilic monomer or monomer component can be present in the polymerizable composition in an amount of 0.1 to 20 unit parts of the polymerizable composition. For example, in a total amount of 30 to 60 unit parts of the hydrophilic monomer or monomer component present in the polymerizable composition, the first hydrophilic monomer or monomer component can comprise 29.9 to 40 unit parts and the second hydrophilic monomer or monomer component can comprise 0.1 to 20 unit parts. In another example, the second hydrophilic monomer or monomer component can be present in the polymerizable composition from 1 to 15 unit parts, or from 2 to 10 unit parts, or from 3 to 7 unit parts.

As used herein, a vinyl-containing monomer is a monomer having a single polymerizable carbon-carbon double bond (i.e., a vinyl polymerizable functional group) present in its molecular structure, wherein the carbon-carbon double bond in the vinyl polymerizable functional group is less reactive than the carbon-carbon double bond present in the acrylate or methacrylate polymerizable functional group under free radical polymerization. In other words, monomers comprising a single acrylate or methacrylate polymerizable group are not considered to be vinyl-containing monomers, although as understood herein, carbon-carbon double bonds are present in acrylate and methacrylate groups. Examples of the polymerizable group having a carbon-carbon double bond (which is less reactive than the carbon-carbon double bond in the acrylate or methacrylate polymerizable group) include vinyl amide, vinyl ether, vinyl ester, and allyl ester polymerizable groups. Thus, as used herein, examples of vinyl-containing monomers include monomers having a single vinyl amide, a single vinyl ether, a single vinyl ester, or a single allyl ester polymerizable group.

In any one or each of the foregoing examples, as previously discussed, the amount of hydrophilic monomer or monomer component (e.g., one or more hydrophilic monomers present in the polymerizable composition) can be from 30 to 60 unit parts of the polymerizable composition. In one example, the hydrophilic monomer or monomer mixture component can comprise 40 to 55 unit parts of the polymerizable composition or 45 to 50 unit parts of the composition. When VMA is present in the polymerizable composition, it can be present in an amount of 30 unit parts to 60 unit parts. In one example, the VMA is present in the polymerizable composition in an amount of about 40 unit parts to about 55 unit parts, or 45 to 50 unit parts. If a hydrophilic monomer, i.e., N-Dimethylacrylamide (DMA), 2-hydroxyethyl methacrylate (HEMA), or 2-hydroxybutyl methacrylate (HOB), is present in the polymerizable composition as an optional second hydrophilic monomer or monomer mixture, it can be present in an amount of about 3 to about 10 unit parts.

Molecular weight as used herein is understood to mean number average molecular weight. The number average molecular weight is the ordinary arithmetic mean or average of the molecular weights of the individual molecules present in the monomer sample. Since the molar masses of the individual molecules in a monomer sample may differ slightly from one another, there may be a certain level of polydispersity in the sample. The term "molecular weight" as used herein refers to the number average molecular weight of a monomer or ingredient, as the siloxane monomer or any other monomer, macromer, prepolymer, or polymer in the polymerizable composition has polydispersity. As one example, a sample of siloxane monomers can have a number average molecular weight of about 15,000 daltons, but if the sample has polydispersity, the actual molecular weight of the individual monomers present in the sample can be in the range of 12,000 daltons to 18,000 daltons.

The number average molecular weight can be an absolute number average molecular weight as determined by proton Nuclear Magnetic Resonance (NMR) end group analysis as understood by one of skill in the art. Molecular weight may also be determined using gel permeation chromatography as understood by one of skill in the art, or may be provided by the supplier of the chemicals.

As used herein, "unit parts" is understood to mean parts by weight. For example, to prepare a formulation described as comprising x unit parts of a siloxane monomer and y unit parts of a hydrophilic monomer, a composition can be prepared by: combining x grams of silicone monomer with y grams of hydrophilic monomer to obtain a total of y + z grams of polymerizable composition, or combining z ounces of silicone with y ounces of hydrophilic monomer to obtain a total of y + z ounces of polymerizable composition, and so forth. Where the composition further comprises other optional ingredients (e.g., x unit parts of a crosslinker), x grams of the crosslinker are combined with z grams of a siloxane monomer and y grams of a hydrophilic monomer to obtain a total of x + y + z grams of the polymerizable composition, and so on. Where the composition comprises other optional ingredients comprising an ingredient component consisting of two ingredients, e.g., a hydrophobic monomer component consisting of a first hydrophobic monomer and a second hydrophobic monomer, w unit parts of the first hydrophobic monomer and v unit parts of the second hydrophobic monomer are combined to obtain a total amount of v + w + x + y + z unit parts of the polymerizable composition, in addition to z unit parts of the siloxane monomer, y unit parts of the hydrophilic monomer, and x unit parts of the crosslinking agent. It is understood that the unit parts of the at least one hydrophobic monomer present in the polymerizable is the sum of the unit parts of the first hydrophobic monomer and the unit parts of the second hydrophobic monomer, e.g., v + w unit parts in this example. Typically, the formulation of the polymerizable composition will consist of ingredients in amounts totaling from about 90 to about 110 unit weight parts. When the amounts of the components in the polymerizable composition are recited herein in unit parts, it is understood that the unit parts of these components are based on formulations that provide a total weight of the composition in the range of about 90 to 110 unit parts. In one example, the unit parts by weight can be based on a formulation that provides a total weight of the composition in a range of from about 95 to 105 unit parts by weight, or from about 98 to 102 unit parts by weight.

As used herein, "silicone hydrogel" or "silicone hydrogel material" refers to a particular hydrogel that includes a Silicone (SiO) component. For example, silicone hydrogels are typically prepared by combining a silicon-containing material with conventional hydrophilic hydrogel precursors. Silicone hydrogel contact lenses are contact lenses, including vision correction contact lenses, comprising a silicone hydrogel material. The siloxane monomer is a siloxane [ -Si-O-Si-]A linked monomer. In the siloxane monomer, each silicon atom may optionally have one or oneMore than one organic group substituent (R) which may be the same or different₁、R₂) Or substituted organic radical substituents, e.g. -SiR₁R₂O-is formed. Similarly, a silicon-free component is a component that contains less than 0.1% (w/w) silicon.

As used herein, the reactive ingredients that can react to form 1 unit part of a polymer are referred to as monomers (regardless of their size). The at least one siloxane monomer may comprise a single siloxane monomer, or may comprise a siloxane monomer component comprised of two or more siloxane monomers. The at least one siloxane monomer may be a hydrophilic siloxane monomer or a hydrophobic siloxane monomer, or may have both hydrophilic and hydrophobic regions, depending on the number and location of any hydrophilic components (e.g., units of ethylene glycol, polyethylene glycol, etc.) present in the molecular structure of the siloxane monomer.

For example, the siloxane monomer can contain a hydrophilic component within the backbone of the siloxane molecule, can contain a hydrophilic component within one or more side chains of the siloxane molecule, or any combination thereof. For example, the siloxane monomer can have at least one ethylene glycol unit adjacent to a polymerizable functional group in the backbone of the siloxane molecule. As used herein, adjacent is understood to mean both directly adjacent and separated by only 10 or fewer carbon atoms. The at least one ethylene glycol unit adjacent to the polymerizable functional group in the backbone of the siloxane molecule can be separated from the polymerizable functional group by a carbon chain length of 1 to 5 units (i.e., wherein the ethylene glycol unit is bonded to the first carbon in a carbon chain length of 1 to 5 units and the polymerizable functional group is bonded to the last carbon in a carbon chain length of 1 to 5 units, in other words, the ethylene glycol unit and the polymerizable group are not directly adjacent but are separated by 1 to 5 carbon atoms). The siloxane monomer may have at least one ethylene glycol unit adjacent to the polymerizable functional groups present on both ends of the siloxane molecular backbone. The siloxane monomer can have at least one ethylene glycol unit present in at least one side chain of the siloxane molecule. The at least one ethylene glycol unit present in at least one side chain of the siloxane molecule can be part of a side chain bonded to a silicon atom in the backbone of the siloxane molecule. The siloxane molecules can have both at least one ethylene glycol unit adjacent to the polymerizable functional groups present on both ends of the siloxane molecule backbone, and at least one ethylene glycol unit present in at least one side chain of the siloxane molecule.

In one embodiment of the present invention, the at least one siloxane monomer can be a multifunctional siloxane monomer. If the siloxane monomer has two functional groups (e.g., two methacrylate groups), it is a difunctional monomer. If the siloxane monomer has three functional groups, it is a trifunctional monomer.

The siloxane monomer may be a siloxane monomer having a polymerizable functional group present on one end of the monomer backbone. The siloxane monomer may be a siloxane monomer having a polymerizable functional group located on both ends of the monomer main chain. The siloxane monomer can be a siloxane monomer having a polymerizable functional group present on at least one side chain of the monomer. The siloxane monomer can be a siloxane monomer having a polymerizable functional group present on only one side chain of the monomer.

The siloxane monomer of the polymerizable composition can be an acrylate-containing siloxane monomer, in other words, a siloxane monomer having at least one acrylate polymerizable functional group as part of its molecular structure. In one example, the acrylate-containing siloxane monomer can be a methacrylate-containing siloxane monomer, i.e., a siloxane monomer having at least one methacrylate polymerizable functional group as part of its molecular structure.

The siloxane monomer can be a siloxane monomer having a number average molecular weight of at least 3,000 daltons. In another example, the siloxane monomer can be a siloxane monomer having a molecular weight of at least 4,000 daltons, or at least 7,000 daltons, or at least 9,000 daltons, or at least 11,000 daltons.

The siloxane monomer can be a siloxane monomer having a molecular weight of less than 20,000 daltons. In another example, the siloxane monomer can be a siloxane monomer having a molecular weight of less than 15,000 daltons, or less than 11,000 daltons, or less than 9,000 daltons, or less than 7,000 daltons, or less than 5,000 daltons.

The siloxane monomer can be a siloxane monomer having a molecular weight of 3,000 daltons to 20,000 daltons. In another example, the siloxane monomer can be a siloxane monomer having a molecular weight of 5,000 daltons to 20,000 daltons, or 5,000 daltons to 10,000 daltons, or 7,000 daltons to 15,000 daltons.

In one example, the siloxane monomer has more than one functional group and a number average molecular weight of at least 3,000 daltons.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer having a number average molecular weight of 400 daltons to 700 daltons; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one monofunctional methacrylate-containing siloxane monomer having a number average molecular weight of from 400 daltons to 700 daltons; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer having a number average molecular weight greater than 7,000 daltons; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In yet another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one difunctional methacrylate-containing siloxane monomer having a number average molecular weight of greater than 7,000 daltons; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The siloxane monomers may comprise poly (organosiloxane) monomers or macromonomers or prepolymers, for example 3- [ TRIS (trimethylsiloxy) silyl ] propylallyl carbamate, or 3- [ TRIS (trimethylsiloxy) silyl ] propylvinyl carbamate, or trimethylsilylethyl vinyl carbonate, or trimethylsilylmethyl vinyl carbonate, or 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS), or 3- (methacryloyloxy-2-hydroxypropoxy) propyl bis (trimethylsiloxy) methylsilane (SiGMA), or methyl bis (trimethylsiloxy) silylpropylglyceryl ethyl methacrylate (SiGEMA), or polydimethylsiloxane having monomethacryloxypropyl ends (MCS-M11), MCR-M07, a, Or polydimethylsiloxane (mPDMS) having monomethacryloxypropyl ends and mono-n-butyl ends, or any combination thereof. In one example of the polymerizable composition of the present invention, the optional siloxane monomer can comprise a first siloxane monomer and a second siloxane monomer, wherein the second siloxane monomer is different from the first siloxane present in the polymerizable composition based on molecular weight, molecular structure, or both molecular weight and structure. For example, the optional second siloxane monomer or at least one third siloxane monomer can be a siloxane monomer of formula (1) having a different molecular weight than the first siloxane monomer in the polymerizable composition. In another example, the optional second siloxane monomer or at least one third siloxane may comprise at least one siloxane disclosed in the following patents: US2007/0066706, US2008/0048350, US3808178, US4120570, US4136250, US 4153641, US470533, US5070215, US5998498, US5760100, US6367929 and EP080539, the entire contents of which are incorporated herein by reference.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymeric lens body that is the reaction product of a polymerizable composition comprising (a) polydimethylsiloxane having monomethacryloxypropyl termini (MCS-M11); and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example of a contact lens of the invention, the siloxane monomer can be a double-ended methacrylate-terminated polydimethylsiloxane having a number average molecular weight of at least 4,000 daltons. It is to be understood that the siloxane monomer is a difunctional monomer.

In one example of the present contact lenses, the siloxane monomer can have a number average molecular weight of at least 4,000 daltons, or at least 7,000 daltons, or at least 9,000 daltons, or at least 11,000 daltons. The siloxane monomer can have a number average molecular weight of less than 20,000 daltons. Thus, in some instances, the siloxane monomer may be considered a macromer, but it will be referred to herein as a monomer because it forms 1 unit part of the formed polymer with the other reactive components in the polymerizable composition.

Examples of the siloxane monomer may include a monofunctional siloxane monomer having at least one urethane linkage, such as examples of the monofunctional siloxane monomer represented by formula (1):

wherein n in formula (1) is 0 to 30, or 10 to 15. In a particular example, the siloxane monomer can be a monomer of formula (1), wherein n in formula (1) is 12 to 13 and its molecular weight is about 1,500 daltons. Examples of such monofunctional siloxane monomers are described in US 6,867,245, which is incorporated herein by reference.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (1):

Wherein n in formula (1) is 0 to 30, or 10 to 15; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS) and (c) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (1):

wherein n in formula (1) is 0 to 30, or 10 to 15; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS); and (c) at least one hydrophilic amide monomer having one N-vinyl group; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein n in formula (1) is 0 to 30, or 10 to 15; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS); and (c) at least one hydrophilic amide monomer having one N-vinyl group; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein F is the calorific value of pure water in melting and is expressed by J/g. In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) at least one siloxane monomer represented by formula (1):

Wherein n in formula (1) is 12 to 13 and its molecular weight is about 1,500 daltons; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS); and (c) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein n in formula (1) is 12 to 13 and its molecular weight is about 1,500 daltons; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS); and (c) at least one hydrophilic amide monomer having one N-vinyl group; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In yet another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (1):

wherein n in formula (1) is 12 to 13 and its molecular weight is about 1,500 daltons; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS); and (c) at least one hydrophilic amide monomer having one N-vinyl group; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Examples of the siloxane monomer may include a bifunctional siloxane monomer having at least two urethane linkages, such as an example of the bifunctional siloxane monomer represented by formula (2):

Wherein n in formula (2) is an integer of about 100 to 150, both m and p in formula (2) are integers of about 5 to about 10, and h is an integer of about 2 to 8. Other examples of such difunctional siloxane monomers and methods of making compounds of formula (2) are described in U.S. patent No. 6,867,245, which is incorporated herein by reference. In a particular example, the siloxane monomer can be a difunctional siloxane monomer having two urethane linkages and a molecular weight greater than 10,000 daltons (e.g., a molecular weight greater than about 15,000 daltons). The siloxane monomer may be a monofunctional siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group. In other words, the CH bonded to the adjacent siloxane group in formula (3) is on a single molecule of the siloxane monomer represented by formula 1₂First R of the group₂A second R which may be a hydrogen atom or a methyl group and which is bonded to C of the methacrylate end group in formula (3)²Or a hydrogen atom or a methyl group, irrespective of the first R in the formula (3)²Whether it is a hydrogen atom or a methyl group. In a specific example of the siloxane monomer of formula (3), m in formula (3) is 4, n in formula (3) is 1, and R in formula (3) ¹Is butyl, and each R in formula (3)²Independently a hydrogen atom or a methyl group. The siloxane monomer of formula (3) may have a molecular weight of less than 2,000 daltons. In some examples, the siloxane monomer of formula (3) has a molecular weight of less than 1,000 daltons. Typically, the molecular weight of the first siloxane monomer is from 400 to 700 daltons. Further details of the siloxane monomer of formula (3) are known from US20090299022, the entire contents of which are incorporated herein by reference. As can be appreciated from formula (3), the first siloxane monomer has a single methacrylic functional end group.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group; wherein the silicone hydrogel contact eyeThe mirror has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, said at least one hydrophilic amide monomer having one N-vinyl group being present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3) ¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, said at least one hydrophilic amide monomer having one N-vinyl group being present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) is 4, n in formula (3) is 1, R in formula (3)¹Is butyl, and each R in formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Wherein m in formula (3) is 4, n in formula (3) is 1, R in formula (3)¹Is butyl, and each R in formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, said at least one hydrophilic amide monomer having one N-vinyl group being present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) is 4, n in formula (3) is 1, R in formula (3)¹Is butyl, and each R in formula (3) ²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, said at leastA hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 unit weight parts; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein F is the calorific value of pure water in melting and is expressed by J/g. The siloxane monomer may be a bifunctional siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration. In some examples where the second siloxane monomer is a monomer represented by formula (4), m in formula (4) is 0, n in formula (4) is an integer from 5 to 15, a is an integer from 65 to 90, b is an integer from 1 to 10, and R in formula (4) ₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. One example of the second siloxane monomer represented by formula (4) is abbreviated as Si2 in the examples. In one example, the number average molecular weight of the second siloxane monomer represented by formula (4) is from about 9,000 daltons to about 10,000 daltons. In other examples, the second siloxane monomer represented by formula (4) is from about 5,000 daltons to about 10,000 daltons. It can be understood that the second siloxane represented by formula (4) is a bifunctional siloxane having two terminal methacrylic groups. Other details of this second siloxane monomerSee US20090234089, the entire contents of which are incorporated herein by reference.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic amide monomer having one N-vinyl group; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic amide monomer having one N-vinyl group, said hydrophilic amide monomer having one N-vinyl group being present in the polymerizable composition in an amount of 30 to 60 unit weight parts; wherein the polymerizable groupThe compound is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) is 0, n in formula (4) is an integer of 5 to 15, a is an integer of 65 to 90, b is an integer of 1 to 10, R in formula (4)₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) is 0, n in formula (4) is an integer of 5 to 15, a is an integer of 65 to 90, b is an integer of 1 to 10, R in formula (4)₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic amide monomer having one N-vinyl group; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein R in the formula (4)₁Selected from hydrogen atoms orA methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) is 0, n in formula (4) is an integer of 5 to 15, a is an integer of 65 to 90, b is an integer of 1 to 10, R in formula (4)₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic amide monomer having one N-vinyl group, said hydrophilic amide monomer having one N-vinyl group being present in the polymerizable composition in an amount of 30 to 60 unit weight parts; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; (b) a second siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic amide monomer having at least one N-vinyl group; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In yet another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a first siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) is 0, n in formula (4) is an integer of 5 to 15, a is an integer of 65 to 90, b is an integer of 1 to 10, R in formula (4)₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; and the configuration of the siloxane units includes a random configuration; (b) a first one represented by formula (3)Disiloxane monomers:

wherein m in formula (3) is 4, n in formula (3) is 1, R in formula (3)¹Is butyl, and each R in formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The siloxane monomer may be a bifunctional siloxane monomer represented by formula (5):

wherein R is³Selected from a hydrogen atom or a methyl group, m in formula (5) represents an integer of 0 to 15, and n in formula (5) represents an integer of 1 to 500. In one example, the siloxane monomer is represented by formula (5), and R³Is methyl, m in formula (5) is 0, and n in formula (5) is an integer of 40 to 60.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a difunctional siloxane monomer represented by formula (5):

wherein R is³Selected from a hydrogen atom or a methyl group, m in formula (5) represents an integer of 0 to 15, and n in formula (5) represents an integer of 1 to 500; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) a difunctional siloxane monomer represented by formula (5):

wherein R is³Is methyl, m in formula (5) is 0, and n in formula (5) is an integer of 40 to 60; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is in an amount of 30 to 60 unit weight partsIs present in the polymerizable composition; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, the siloxane monomer may be a difunctional siloxane monomer represented by formula (6), and may be obtained from Sulfast (Gelest), Morrisville, Pa., under the product code DMS-R18:

in one example, the siloxane of formula (6) has a number average molecular weight of about 4,000 to about 4,500 daltons.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) a difunctional siloxane monomer represented by formula (6):

a number average molecular weight of from 4,000 daltons to 4,500 daltons; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In one example, the polymerizable composition can include a siloxane monomer component comprised of a first siloxane monomer and a second siloxane monomer. The second siloxane monomer can have more than one functional group, or can have a number average molecular weight of at least 3,000 daltons, or can have both more than one functional group and a number average molecular weight of at least 3,000 daltons. If the second siloxane monomer has two functional groups (e.g., two methacrylate groups), it is a difunctional monomer. If the second siloxane monomer has three functional groups, it is a trifunctional monomer.

When the polymerizable composition comprises a first siloxane and a second siloxane, the first siloxane monomer and the second siloxane monomer can be present in the following amounts: the ratio of the first siloxane monomer to the second siloxane monomer is at least 1: 1 (based on unit parts), or at least 2: 1 (based on unit parts). For example, the first siloxane monomer and the second siloxane monomer can be present in the polymerizable composition in a ratio of about 2: 1 to about 10: 1 (based on unit parts). In another example, the first siloxane monomer and the second siloxane monomer can be present in the polymerizable composition in a ratio of about 3: 1 to about 6: 1 (based on unit parts). In one example, the first siloxane monomer and the second siloxane monomer can be present in the polymerizable composition in a ratio of about 4: 1 (based on unit parts).

When the polymerizable composition comprises at least one siloxane monomer, the total amount of siloxane monomer present in the polymerizable composition (e.g., the sum of the unit parts of the optional first siloxane monomer, the optional second siloxane monomer, and any other optional siloxane monomer present in the polymerizable composition) can be from about 10 to about 60 unit parts, or from about 25 to about 50 unit parts, or from about 35 to about 40 unit parts.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the total amount of siloxane monomers present in the polymerizable composition is from 25 unit parts to 50 unit parts, said at least one hydrophilic amide monomer having one N-vinyl group being present in the polymerizable composition in an amount of from 30 to 60 unit weight parts; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In one particular example, where the siloxane monomer component comprises a combination of at least two siloxane monomers each having a different molecular weight, the molecular weight of the first siloxane monomer can be less than 2,000 daltons. In some examples, the molecular weight of the first siloxane monomer can be less than 1,000 daltons. Typically, the molecular weight of the first siloxane monomer is from 400 to 700 daltons.

Where at least one siloxane monomer is present in the polymerizable composition, as previously discussed, the at least one siloxane monomer can comprise a first siloxane monomer and a second siloxane monomer. In one example, the first siloxane monomer can consist of a siloxane monomer of formula (2) and the second siloxane monomer can consist of a siloxane monomer of formula (1). In another example, the first siloxane monomer can consist of a siloxane monomer of formula (1) and the second siloxane monomer can consist of a siloxane monomer of formula (2). In another example, the first siloxane monomer can consist of a siloxane monomer of formula (3) and the second siloxane can consist of a siloxane monomer of formula (4). In another example, the first siloxane monomer can consist of a siloxane monomer of formula (4) and the second siloxane monomer can consist of a siloxane monomer of formula (3). In another example, the first siloxane monomer can consist of a siloxane monomer of formula (1) and the second siloxane monomer can consist of a siloxane monomer of formula (4). In yet another example, the first siloxane monomer can consist of a siloxane monomer of formula (4) and the second siloxane monomer can consist of a siloxane monomer of formula (1). In any or all of the examples described herein, the siloxane monomer component can comprise a third siloxane monomer. For example, the third siloxane monomer can consist of a siloxane monomer of formula (5).

Optionally, the polymerizable compositions of the present invention may optionally comprise at least one silicon-free hydrophobic monomer. Hydrophobic monomers are understood to be non-silicone polymerizable constituents which have only one polymerizable functional group present in their molecular structure. The at least one hydrophobic monomer of the polymerizable composition can be one hydrophobic monomer, or can comprise a hydrophobic monomer component consisting of at least two hydrophobic monomers. Examples of hydrophobic monomers that can be used in the polymerizable compositions disclosed herein include, but are not limited to, acrylate-containing hydrophobic monomers or methacrylate-containing hydrophobic monomers, or any combination thereof. Examples of hydrophobic monomers include, but are not limited to, methyl acrylate, or ethyl acrylate, or propyl acrylate, or isopropyl acrylate, or cyclohexyl acrylate, or 2-ethylhexyl acrylate, or Methyl Methacrylate (MMA), or ethyl methacrylate, or propyl methacrylate, or butyl acrylate, or vinyl acetate, or vinyl propionate, or vinyl butyrate, or vinyl valerate, or styrene, or chloroprene, or vinyl chloride, or vinylidene chloride, or acrylonitrile, or 1-butene, or butadiene, or methacrylonitrile, or vinyl toluene, or vinyl ethyl ether, or perfluorohexylethylthiocarbonylaminoethyl methacrylate, or isobornyl methacrylate, or trifluoroethyl methacrylate, or hexafluoroisopropyl methacrylate, or hexafluorobutyl methacrylate, or, Or ethylene glycol methyl ether methacrylate (EGMA), or any combination thereof. In one particular example, the hydrophobic monomer or monomer component may comprise or consist of MMA or EGMA or both.

When present in the polymerizable composition, the hydrophobic monomer or monomer component can be present in an amount of about 5 to about 25 unit parts, or about 10 to about 20 unit parts.

In one example, the hydrophobic monomer component can comprise at least two hydrophobic monomers each having a different polymerizable functional group. In another example, the hydrophobic monomer component can comprise at least two hydrophobic monomers each having the same polymerizable functional group. The hydrophobic monomer component may comprise or consist of two hydrophobic monomers, both having the same polymerizable functional group. In one example, the hydrophobic monomer component can comprise or consist of two hydrophobic methacrylate-containing monomers. The hydrophobic monomer component may comprise or consist of MMA and EGMA. In one example, the at least two hydrophobic monomers of the hydrophobic monomer component can comprise or consist of MMA and EGMA, and the ratio of unit parts of MMA to unit parts of EGMA present in the polymerizable composition can be from about 6: 1 to about 1: 1. The ratio of unit parts of MMA to EGMA present in the polymerizable composition can be about 2: 1 (based on unit parts of MMA to unit parts of EGMA).

According to the invention, a crosslinker is understood to be a monomer having more than one polymerizable functional group (e.g. two or three or four polymerizable functional groups) as part of its molecular structure, i.e. a multifunctional monomer, such as a difunctional or trifunctional or tetrafunctional monomer. Silicon-free crosslinkers that may be used in the polymerizable compositions disclosed herein include, for example, but are not limited to, allyl (meth) acrylate, or lower alkylene glycol di (meth) acrylate, or poly (lower alkylene) glycol di (meth) acrylate, or lower alkylene di (meth) acrylate, or divinyl ether, or divinyl sulfone, or divinylbenzene and trivinylbenzene, or trimethylolpropane tri (meth) acrylate, or neopentylglycol tetra (meth) acrylate, or bisphenol a di (meth) acrylate, or methylenebis (meth) acrylamide, or triallyl phthalate and diallyl phthalate, or any combination thereof. Crosslinkers as disclosed in some formulations of examples 1-4 include, for example, Ethylene Glycol Dimethacrylate (EGDMA), or triethylene glycol dimethacrylate (TEGDMA), or triethylene glycol divinyl ether (TEGDVE), or any combination thereof. In one example, the crosslinking agent can have a molecular weight of less than 1500 daltons, or less than 1000 daltons, or less than 500 daltons, or less than 200 daltons.

In one example, the crosslinker or crosslinker component can comprise or consist of a vinyl-containing crosslinker. As used herein, a vinyl-containing crosslinking agent is a monomer having at least two polymerizable carbon-carbon double bonds (i.e., at least two vinyl polymerizable functional groups) present in its molecular structure, wherein each of the at least two polymerizable carbon-carbon double bonds present in the vinyl polymerizable functional groups of the vinyl-containing crosslinking agent is less reactive than the carbon-carbon double bonds present in the acrylate or methacrylate polymerizable functional groups. Although as understood herein, carbon-carbon double bonds are present in the acrylate and methacrylate polymerizable functional groups, crosslinkers comprising one or more acrylate or methacrylate polymerizable groups (e.g., acrylate-containing crosslinkers or methacrylate-containing crosslinkers) are not considered vinyl-containing crosslinkers. Polymerizable functional groups having a carbon-carbon double bond that are less reactive than the carbon-carbon double bond of the acrylate or methacrylate polymerizable group include, for example, vinyl amide, vinyl ester, vinyl ether, and allyl ester polymerizable functional groups. Thus, vinyl-containing crosslinkers as used herein include, for example, crosslinkers having at least two polymerizable functional groups selected from: vinyl amides, vinyl ethers, vinyl esters, allyl esters, and any combination thereof. The mixed vinyl-containing crosslinking agent used herein is the following crosslinking agent: which has at least one polymerizable carbon-carbon double bond (i.e., at least one vinyl polymerizable functional group) present in its structure and having a reactivity weaker than that of the carbon-carbon double bond present in the acrylate or methacrylate polymerizable functional group, and at least one polymerizable functional group present in its structure and having a carbon-carbon double bond equivalent to at least that of the acrylate or methacrylate polymerizable functional group.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; and (c) at least one vinyl-containing crosslinking agent; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

When present in the polymerizable composition, the vinyl-containing crosslinking agent or crosslinker component may be present in an amount of from about 0.01 unit parts to about 2.0 unit parts, or from about 0.01 unit parts to about 0.80 unit parts, or from about 0.01 unit parts to about 0.30 unit parts, or from about 0.05 unit parts to about 0.20 unit parts, or in an amount of about 0.1 unit parts.

In one example, the crosslinker or crosslinker component can comprise or consist of a vinyl-free crosslinker (i.e., a crosslinker that is not a vinyl-containing crosslinker). For example, the non-vinyl crosslinker or crosslinker component can comprise or consist of an acrylate-containing crosslinker (i.e., a crosslinker having at least two acrylate polymerizable functional groups), or a methacrylate-containing crosslinker (i.e., at least two methacrylate polymerizable functional groups), or at least one acrylate-containing crosslinker and at least one methacrylate-containing crosslinker.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; (c) at least one vinyl-containing crosslinking agent; and (d) at least one vinyl-free crosslinking agent; wherein the polymerizable composition is free of DMA, and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

When present in the polymerizable composition, no vinyl crosslinker or crosslinker may be present in an amount of from about 0.01 unit parts to about 5 unit parts, or from about 0.1 unit parts to about 4 unit parts, or from about 0.3 unit parts to about 3.0 unit parts, or from about 0.2 unit parts to about 2.0 unit parts.

The crosslinker component may comprise or consist of a combination of two or more crosslinkers each having a different polymerizable functional group. For example, the crosslinker component can comprise a vinyl-containing crosslinker and an acrylate-containing crosslinker. The crosslinker component may comprise a vinyl-containing crosslinker and a methacrylate-containing crosslinking group. The crosslinker component may comprise or consist of a vinyl ether-containing crosslinker and a methacrylate-containing crosslinker.

When the polymerizable composition includes at least one crosslinking agent, the total amount of crosslinking agent (i.e., the total unit parts of all crosslinking agents present in the polymerizable composition) can be in an amount of from about 0.01 unit parts to about 5 unit parts, or from about 0.1 unit parts to about 4 unit parts, or from about 0.3 unit parts to about 3.0 unit parts, or from about 0.2 unit parts to about 2.0 unit parts, or from about 0.6 unit parts to about 1.5 unit parts.

In one example, where the polymerizable composition of the present invention comprises at least one vinyl-containing crosslinking agent, the total amount of vinyl-containing crosslinking agent present in the polymerizable composition can be in an amount of from about 0.01 unit parts to about 2.0 unit parts, or from about 0.01 unit parts to about 0.80 unit parts, or from about 0.01 unit parts to about 0.30 unit parts, or from about 0.05 unit parts to about 0.20 unit parts, or in an amount of about 0.1 unit parts.

Where the polymerizable composition comprises a first siloxane monomer and at least one crosslinker, the first siloxane monomer (e.g., the first siloxane monomer present as the only siloxane monomer of the polymerizable composition, or the first siloxane monomer present as part of a siloxane monomer component comprising two or more siloxane monomers) and the at least one crosslinker (i.e., a single crosslinker or a crosslinker component consisting of two or more crosslinkers) can be present in the polymerizable composition in a ratio of at least 10: 1 based on the total parts by weight of the first siloxane monomer to the total parts by weight of the at least one crosslinker (i.e., the sum of the parts by weight of all vinyl-containing crosslinkers present in the polymerizable composition). For example, the ratio can be at least 25: 1 or at least 50: 1 or at least 100: 1 (based on parts by weight).

In one example, the at least one crosslinker can comprise at least one vinyl-containing crosslinker and at least one methacrylate-containing crosslinker. In another example, the at least one crosslinking agent may consist of only one or more vinyl-containing crosslinking agents. In another example, the at least one crosslinking agent can comprise or consist of at least one vinyl ether-containing crosslinking agent. In yet another example, the at least one crosslinking agent may consist of only one or more vinyl-containing crosslinking agents. In a particular example, the at least one crosslinking agent can comprise or consist of at least one vinyl ether-containing crosslinking agent.

When the at least one crosslinking agent comprises or consists of at least one vinyl-containing crosslinking agent (i.e., a single vinyl-containing crosslinking agent or a vinyl-containing crosslinking agent component consisting of two or more vinyl-containing crosslinking agents), the first siloxane monomer and the at least one vinyl-containing crosslinking agent can be present in the polymerizable composition in a ratio of at least about 50: 1 based on the total number of unit parts of the first siloxane monomer to the total number of unit parts of the at least one vinyl-containing crosslinking agent (i.e., the sum of the units of all vinyl-containing crosslinking agents present in the polymerizable composition). For example, the ratio can be from about 50: 1 to about 500: 1, or from about 100: 1 to about 400: 1, or from about 200: 1 to about 300: 1 (based on parts by weight).

Where the polymerizable composition comprises the first siloxane monomer and at least one other siloxane monomer (i.e., the second siloxane and optionally the third siloxane monomer, the fourth siloxane monomer, etc.) in combination with at least one crosslinker, the siloxane monomer and the at least one vinyl-containing monomer can be present in the polymerizable composition in a ratio of at least about 100: 1 based on the total number of unit parts of each siloxane monomer present in the polymerizable composition (i.e., the sum of the unit parts of the first siloxane and second siloxane monomers and, if present, the third siloxane monomer, etc.) to the total number of unit parts of the at least one vinyl-containing crosslinker (i.e., the sum of the unit parts of all vinyl-containing crosslinkers present in the polymerizable composition). For example, the ratio can be from about 50: 1 to about 500: 1, or from about 100: 1 to about 400: 1, or from about 200: 1 to about 300: 1 (based on parts by weight).

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; (b) at least one hydrophilic amide monomer having at least one N-vinyl group, wherein the at least one hydrophilic amide monomer having one N-vinyl group is present in the polymerizable composition in an amount of 30 to 60 parts by weight; and (c) at least one vinyl-containing crosslinking agent; wherein the ratio of siloxane monomer to vinyl crosslinker present in the polymerizable composition is from 50: 1 to 500: 1; the polymerizable composition is free of DMA, and the silicone hydrogel contact lens; and has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The polymerizable composition may optionally include one or more organic diluents, one or more polymerization initiators (i.e., Ultraviolet (UV) initiators or thermal initiators or both), or one or more UV absorbers, or one or more colorants, or one or more oxygen scavengers, or one or more chain transfer agents, or any combination thereof. These optional ingredients may be polymerizable or non-polymerizable ingredients. In one example, the polymerizable composition can be free of diluents, which in this regard are free of any organic diluents that can achieve miscibility between the silicone and other lens forming ingredients (e.g., optional hydrophilic monomers, hydrophobic monomers, and crosslinking agents). Additionally, many of the polymerizable compositions of the present invention are substantially free of water (e.g., contain no more than 3.0% or 2.0% by weight water).

The polymerizable compositions disclosed herein can optionally comprise one or more organic diluents, i.e., the polymerizable compositions can comprise an organic diluent, or can comprise an organic diluent component comprising two or more organic diluents. Organic diluents that may optionally be included in the polymerizable compositions of the present invention include alcohols, including lower alcohols, such as, but not limited to, pentanol, or hexanol, or octanol, or decanol, or any combination thereof. When included, the organic diluent or organic diluent component can be provided in the polymerizable composition in an amount of from about 1 unit part to about 70 unit parts, or from about 2 unit parts to about 50 unit parts, or from about 5 unit parts to about 30 unit parts.

The polymerizable composition of the present invention may optionally comprise one or more polymerization initiators, i.e., the polymerizable composition may comprise an initiator, or may comprise an initiator component comprising two or more polymerization initiators. Polymerization initiators that may be included in the polymerizable compositions of the present invention include, for example, azo compounds or organic peroxides or both. Initiators that may be present in the polymerizable composition include, for example, but are not limited to, benzoin ethyl ether, or benzyl dimethyl ketal, or α, α -diethoxyacetophenone, or 2, 4, 6-trimethylbenzoyldiphenylphosphine oxide, or benzoin peroxide, or t-butyl peroxide, or azobisisobutyronitrile, or azobisdimethylvaleronitrile, or any combination thereof. The UV photoinitiator may include, for example, a phosphine oxide, such as diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide, or benzoin methyl ether, or 1-hydroxycyclohexyl phenyl ketone, or Darocur (available from BASF, Florham Park, NJ, USA (USA)), or goruaur (available from BASF), or any combination thereof. In many of examples 1-4 disclosed herein, the polymerization initiator is the thermal initiator 2, 2' -azobis-2-methylpropanenitrile (VAZO-64 from dupont DE Nemours & Co., Wilmington, state of tera (DE), usa). Other commonly used thermal initiators may include 2, 2 '-azobis (2, 4-dimethylvaleronitrile) (VAZO-52) and 1, 1' -azobis (cyanocyclohexane) (VAZO-88). The polymerization initiator or initiator component may be present in the polymerizable composition in an amount of from about 0.01 unit weight parts to about 2.0 unit weight parts, or from about 0.1 unit weight parts to about 1.0 unit weight parts, or from about 0.2 unit weight parts to about 0.6 unit weight parts.

Optionally, the polymerizable composition of the present invention may comprise one or more UV absorbers, i.e., the polymerizable composition may comprise one UV absorber, or may comprise a UV absorber component comprising two or more UV absorbers. UV absorbers that may be included in the polymerizable compositions of the present invention include, for example, benzophenone, or benzotriazole, or any combination thereof. In many of examples 1-4 disclosed herein, the UV absorber is 2- (3- (2H-benzotriazol-2-yl) -4-hydroxy-phenyl) ethyl methacrylate (nobloc)7966 from Nolamaceae (Noramco), Athens (Athens), Georgia (GA), USA. The UV absorber can also be 2- (4-benzoyl-3-hydroxyphenoxy) ethyl acrylate (UV-416). The UV absorber or UV absorber component can be present in the polymerizable composition in an amount of from about 0.01 unit weight parts to about 5.0 unit weight parts, or from about 0.1 unit weight parts to about 3.0 unit weight parts, or from about 0.2 unit weight parts to about 2.0 unit weight parts.

The polymerizable compositions of the present invention can also optionally include at least one colorant (i.e., one colorant or a colorant component comprising two or more colorants), but encompass both tinted lens products and clear lens products. In one example, the colorant can be a reactive dye or pigment effective to provide color to the resulting lens product. The colorant or colorant component in the polymerizable composition can comprise a polymerizable colorant, or can comprise a non-polymerizable colorant, or any combination thereof. The polymerizable colorant may be a colorant whose molecular structure contains a polymerizable functional group, or may be a colorant whose molecular structure includes both a monomer portion and a dye portion, i.e., the colorant may be a monomer-dye compound. The molecular structure of the colorant may comprise a beta sulfone functional group, or may comprise a triazine functional group. Colorants can include, for example, VAT blue 6(7, 16-dichloro-6, 15-dihydroanthracene azine-5, 9, 14, 18-tetrone), or 1-amino-4- [3- (. beta. -sulfatoethylsulfonyl) anilino ] -2-anthraquinone sulfonic acid (c.i. reactive blue 19, RB-19), or a monomer-dye compound of reactive blue 19 with hydroxyethyl methacrylate (RB-19HEMA), or 1, 4-bis [4- [ (2-methacryloyl-oxyethyl) phenylamino ] anthraquinone (reactive blue 246, RB-246, available from Arran Chemical company, astlon (Athlone), Ireland (Ireland)), or 1, 4-bis [ (2-hydroxyethyl) amino ] -9, 10-anthracenedione bis (2-propenoic acid) ester (RB-247), or reactive blue 4(RB-4), or a monomer-dye compound of reactive blue 4 and hydroxyethyl methacrylate (RB-4HEMA or "blue HEMA"), or any combination thereof. In one example, the colorant or colorant component can comprise a polymerizable colorant. The polymerizable colorant component can comprise, for example, RB-246, or RB-274, or RB-4HEMA, or RB-19HEMA, or any combination thereof. Examples of monomer-dye compounds include RB-4HEMA and RB-19 HEMA. Further examples of monomer-dye compounds are described in US5944853 and US 72169975, the entire contents of both cases being incorporated herein by reference. Other exemplary colorants are disclosed, for example, in U.S. patent application publication No. 2008/0048350, the entire contents of which are incorporated herein by reference. In many of examples 1-4 disclosed herein, the colorant is a reactive blue dye, such as those described in US4997897, the entire contents of which are incorporated herein by reference. Other suitable colorants for use according to the present invention are phthalocyanine pigments (e.g. phthalocyanine blue or phthalocyanine green), or chromium-aluminum-cobalt oxide, or chromium oxide, or various red, yellow, brown and black iron oxides, or any combination thereof. Opacifiers such as titanium dioxide may also be included. For some applications, combinations of colorants having different colors may be employed as the colorant component. If employed, the colorant or colorant component can be present in the polymerizable composition in an amount ranging from about 0.001 unit parts to about 15.0 unit parts, or from about 0.005 unit parts to about 10.0 unit parts, or from about 0.01 unit parts to about 8.0 unit parts.

The polymerizable composition of the present invention may optionally comprise at least one oxygen scavenger, i.e., one oxygen scavenger or an oxygen scavenger component comprising two or more oxygen scavengers. Examples of oxygen scavengers that may be included as an oxygen scavenger or oxygen scavenger component of the polymerizable composition of the present invention include, for example, vitamin E, or a phenolic compound, or a phosphite compound, or a phosphine compound, or an amine oxide compound, or any combination thereof. For example, the oxygen scavenger or oxygen scavenger component may consist of or comprise a phosphine-containing compound. In many of examples 1-4 disclosed herein, the oxygen scavenger or oxygen scavenger component is a phosphine-containing compound, such as triphenylphosphine, or a polymerizable form of triphenylphosphine, such as diphenyl (p-vinylphenyl) phosphine.

Chain transfer is a polymerization reaction that transfers the activity of a growing polymer chain to another molecule, thereby reducing the average molecular weight of the final polymer. The polymerizable composition of the present invention may optionally comprise at least one chain transfer agent, i.e., may comprise one chain transfer agent or may comprise a chain transfer agent component comprising at least two chain transfer agents. Examples of chain transfer agents that may be included as chain transfer agents or chain transfer components of the polymerizable compositions of the present invention include, for example, thiol compounds, or halocarbon compounds, or C3 to C5 hydrocarbons, or any combination thereof. In many of examples 1-4 disclosed herein, the chain transfer agent is allyloxyethanol. When present in the polymerizable composition, the chain transfer agent or chain transfer agent component may be present in an amount of from about 0.01 unit parts to about 1.5 unit parts, for example from about 0.1 unit parts to about 0.5 unit parts.

It is also understood that reference to a contact lens formed from the compositions described herein refers to a lens body having an anterior surface and a posterior surface, the posterior surface configured to be placed in contact with the cornea of the eye of a contact lens wearer. The lens body of the invention may be completely transparent. Alternatively, where the contact lens is a cosmetic lens configured to change the appearance of the iris of a contact lens wearer, the lens body can include a transparent optical zone.

The invention is useful for contact lenses that can be contacted with epithelial tissue or other ocular tissue when worn. The invention is useful for all known types of contact lenses, including soft and hard lens materials. In examples of the present contact lenses, the contact lenses are lenses having at least one optical zone configured to provide vision correction, increase visual acuity, or both. For example, the optical zone can be configured to provide spherical correction, astigmatic correction, or third or higher order correction. The optical zone can be configured to improve visual acuity at near viewing distances, at distance viewing distances, or at both near and distance viewing distances. Other features and examples of the present contact lenses are illustrated in the following sections.

The hydrogel contact lenses of the invention are vision correcting or vision enhancing contact lenses. The lens can be a spherical lens or an aspherical lens. The lens may be a single focal lens or a multifocal lens, including a bifocal lens. In one example, the present lenses are rotationally stable lenses, such as rotationally stable toric contact lenses. The rotationally stabilized contact lens can be a contact lens comprising a lens body including a ballast (ballast). For example, the lens body can have a prismatic weight, a peripheral weight, and/or one or more thinned upper and lower regions.

The lenses of the invention also include a lens body that includes a peripheral edge region. The peripheral edge region may include a rounded portion. For example, the peripheral edge region may include a rounded trailing edge surface, a rounded leading edge surface, or a combination thereof. The peripheral edge may be completely rounded from the front surface to the rear surface. Thus, it can be appreciated that the lens body of the lenses of the invention can comprise a circular peripheral edge.

The contact lenses of the present invention are ophthalmically acceptable contact lenses in that they are configured to be placed or disposed on the cornea of an animal or human eye. An ophthalmically acceptable contact lens as used herein is understood to be a contact lens having at least one of a plurality of different properties as described below. An ophthalmically acceptable contact lens can be formed from and packaged in ophthalmically acceptable ingredients such that the lens is non-cytotoxic and does not release irritating and/or toxic ingredients during wear. An ophthalmically acceptable contact lens can have a clarity in the lens optic zone (i.e., the portion of the lens that provides vision correction) sufficient for its intended use in contact with the cornea of an eye, e.g., a visible light transmittance of at least 80%, or at least 90%, or at least 95%. Ophthalmically acceptable contact lenses can have sufficient mechanical properties to facilitate lens handling and care over a duration based on their expected lifetime. For example, its modulus, tensile strength, and elongation may be sufficient to withstand insertion, wearing, removal, and optionally cleaning during the lens' expected lifetime. The level of these desirable properties will vary depending on the intended life and use of the lens (e.g., disposable daily, multiple use monthly, etc.). An ophthalmically acceptable contact lens can have an effective or appropriate ion current to substantially inhibit or substantially prevent corneal staining, e.g., corneal staining that is more severe than superficial or moderate corneal staining, after 8 or more hours of continuous lens wear on the cornea. Ophthalmically acceptable contact lenses can have sufficient oxygen permeability levels to allow oxygen to reach the cornea of the eye wearing the lens in an amount sufficient to maintain long-term corneal health. An ophthalmically acceptable contact lens can be one that does not cause significant or excessive corneal edema of the eye on which the lens is worn, e.g., no more than about 5% or 10% corneal edema after being worn on the cornea of the eye during overnight sleep. An ophthalmically acceptable contact lens can be a lens that allows movement of the lens on the cornea of an eye wearing the lens sufficient to facilitate tear flow between the lens and the eye, in other words, without adhering the lens to the eye with sufficient force to impede normal lens movement, and with a sufficiently low level of movement on the eye to allow vision correction. An ophthalmically acceptable contact lens can be a lens that permits the lens to be worn on-eye without excess or significant discomfort and/or irritation and/or pain. An ophthalmically acceptable contact lens can be a lens that inhibits or substantially prevents the deposition of lipids and/or proteins sufficiently to allow the lens wearer to remove the lens due to the deposition. The ophthalmically acceptable contact lens can have at least one of a water content, or a surface wettability, or a modulus or design, or any combination thereof, effective to promote ophthalmically compatible contact lens wear by a contact lens wearer, at least during a day. Ophthalmically compatible wear is understood to mean that the lens wearer produces little or no discomfort when wearing the lens and little or no corneal staining occurs. Conventional clinical methods can be used to determine whether a contact lens is ophthalmically acceptable, such as those implemented by an eye care practitioner and as will be appreciated by those skilled in the art.

In one example of the invention, a contact lens may have an ophthalmically acceptably wettable lens surface. For example, a contact lens can have an ophthalmically acceptably wettable lens surface when the polymerizable composition used to form the polymeric lens body does not contain an internal wetting agent, or when the polymerizable composition used to form the polymeric lens body does not contain an organic diluent, or when the polymeric lens body is extracted in water or an aqueous solution that does not contain a volatile organic solvent, or when the polymeric lens body is not surface plasma treated, or any combination thereof.

One method commonly used in the art to increase the wettability of a contact lens surface is to apply a treatment to or modify the lens surface. According to the present invention, silicone hydrogel contact lenses can have ophthalmically acceptably wettable lens surfaces without surface treatment or surface modification. Surface treatments include, for example, plasma and corona treatments that increase the hydrophilicity of the lens surface. While one or more surface plasma treatments may be applied to the lens bodies of the present invention, this is not necessary to obtain silicone hydrogel contact lenses having ophthalmically acceptably wettable lens surfaces when fully hydrated. In other words, in one example, the present silicone hydrogel contact lenses may not be surface plasma or corona treated.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the polymeric lens body is not exposed to the plasma treatment and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Surface modification includes binding a wetting agent to a lens surface, for example, binding a wetting agent such as a hydrophilic polymer to at least one lens surface by chemical bonding or another form of chemical interaction. In some cases, the wetting agent can be bound to the lens surface and at least a portion of the polymeric matrix of the lens (i.e., at least a portion of the lens body) by chemical bonding or another form of chemical interaction. An ophthalmically acceptably wettable lens surface of the present invention can have ophthalmically acceptable wettability in the absence of a wetting agent (e.g., a polymeric or non-polymeric material) at least bound to the lens surface. While one or more wetting agents may be incorporated into the lenses of the invention, this is not necessary to obtain silicone hydrogel contact lenses having ophthalmically acceptably wettable lens surfaces when fully hydrated. Thus, in one example, the lenses of the invention can comprise a wetting agent, e.g., a hydrophilic polymer and including polyvinylpyrrolidone, bound to the lens surface. Alternatively, in another example, the silicone hydrogel contact lenses of the invention may be free of wetting agents bound to the lens surface.

Another approach to increasing the wettability of a lens is to physically entrap wetting agents within the lens body or contact lens, for example, by: the wetting agent is introduced into the lens body as the lens body expands and then the lens body is returned to a less expanded state, thereby trapping a portion of the wetting agent within the lens body. The wetting agent may be permanently trapped within the lens body, or may be released from the lens over time (e.g., during wear). An ophthalmically acceptably wettable lens surface of the present invention can have ophthalmically acceptable wettability without the presence of wetting agents (e.g., polymeric or non-polymeric materials) physically entrapped in the lens body after formation of the polymeric lens body. While one or more wetting agents may be physically entrapped in the lenses of the invention, this is not necessary to obtain silicone hydrogel contact lenses having ophthalmically acceptably wettable lens surfaces when fully hydrated. Thus, in one example, the lenses of the invention may comprise a wetting agent entrapped within the lens, for example, a hydrophilic polymer and including polyvinylpyrrolidone. Alternatively, the hydrogel contact lenses of the invention (e.g., the silicone hydrogel contact lenses of the invention) may be free of wetting agents physically entrapped within the lenses. Physical entrapment, as used herein, means that the wetting agent or other ingredient is immobilized in the polymeric matrix of the lens with little or no chemical bonding or interaction between the wetting agent and or other ingredient and the polymeric matrix. This is in contrast to components that are chemically bonded to the polymeric substrate by, for example, ionic bonding, covalent bonding, van der Waals forces, and the like.

Another method commonly used in the industry to increase the wettability of hydrogel contact lenses, such as silicone hydrogel contact lenses, includes adding one or more wetting agents to the polymerizable composition. In one example, the wetting agent can be a polymeric wetting agent. However, when the polymerizable composition used to form the polymeric lens body is free of wetting agents, the contact lenses of the invention can have an ophthalmically acceptably wettable lens surface. While one or more wetting agents may be included in the polymerizable compositions of the present invention to increase the wettability of the hydrogel contact lenses of the present invention, this is not necessary to obtain hydrogel contact lenses having ophthalmically acceptably wettable lens surfaces. In other words, in one example, the hydrogel contact lenses of the invention can be formed from a polymerizable composition that does not contain a wetting agent. Alternatively, in another example, the polymerizable composition of the present invention can further comprise a wetting agent.

In one example, the wetting agent can be an internal wetting agent. The internal wetting agent can be incorporated within at least a portion of the polymeric matrix of the lens. For example, the internal wetting agent can be incorporated within at least a portion of the lens polymeric matrix by chemical bonding or another form of chemical interaction. In some cases, wetting agents can also bind to the lens surface. The internal wetting agent may comprise a polymeric material or a non-polymeric material. While one or more internal wetting agents may be incorporated into the polymeric matrix of the lenses of the invention, this is not necessary to obtain hydrogel contact lenses having an ophthalmically acceptably wettable lens surface when fully hydrated. Thus, in one example, the lenses of the invention can comprise an internal wetting agent bound to at least a portion of the lens polymeric matrix. Alternatively, in another example, the hydrogel contact lenses of the invention can be free of an internal wetting agent bound to at least a portion of the lens polymeric matrix.

In another example, the wetting agent can be an internal polymeric wetting agent. The internal polymeric wetting agent can be present in the polymeric lens body as part of an Interpenetrating Polymer Network (IPN) or a semi-IPN. Interpenetrating polymer networks are formed from at least two polymers, each crosslinked to itself, but not to each other. Similarly, a semi-IPN is formed from at least two polymers, at least one of which is cross-linked to itself but not to the other, and the other is neither cross-linked to itself nor to each other. In one example of the invention, a contact lens can have an ophthalmically acceptably wettable lens surface when the polymeric lens body is free of an internal polymeric wetting agent present in the lens body in the form of an IPN or semi-IPN. Alternatively, the contact lens can comprise an internal polymeric wetting agent in the form of an IPN or semi-IPN present in the lens body.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the polymerizable composition is free of DMA and free of polymeric internal wetting agent, and has an equilibrium freezable water content of at least 25% wt/wt as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In yet another example, the wetting agent can be a linking compound present in the polymerizable composition used to form the lens body, or a linking agent that is physically trapped within the polymerized lens body after the lens body has been formed. Where the wetting agent is a linking compound, after polymerization of the lens body or entrapment of the linking agent in the polymerized lens body, the linking compound can then link the wetting agent to the lens body upon contact of the lens body with a second wetting agent. The linking can be performed as part of the manufacturing process (e.g., as a washing process), or can be performed while the lens body is in contact with the packaging solution. The linkage may be in the form of an ionic or covalent bond, or in the form of van der waals attraction. The linking agent can comprise organoboronic acid moieties or groups, such that the polymeric organoboronic acid moieties or groups are present in the polymeric lens body, or such that the organoboronic acid moieties or groups are physically entrapped in the polymeric lens body. For example, where the chain linking agent comprises an organic boronic acid form, the second wetting agent may comprise a poly (vinyl alcohol) form bound to the organic boronic acid form. Optionally, the silicone hydrogel contact lenses of the present invention can be understood to be free of a linking agent. In one example, the silicone hydrogel contact lenses can be free of organoboronic acid moieties or groups (including polymerized organoboronic acid moieties or groups), i.e., in particular, the silicone hydrogel contact lenses can be formed from polymerizable compositions that are free of organoboronic acid forms (e.g., polymerizable forms of organoboronic acids, including vinylphenyl organoboronic acids (VPBs)), can be formed from polymers that are free of units derived from polymerizable forms of organoboronic acids (e.g., vinylphenyl organoboronic acids (VPBs)), and the polymerized lens bodies and the silicone hydrogel contact lenses can be free of organoboronic acid forms (including polymerized or non-polymerized forms of organoboronic acids) physically entrapped therein. Alternatively, the polymerizable composition, or the polymeric lens body, or the hydrogel contact lens, or any combination thereof, can comprise at least one linking agent.

In addition to including wetting agents and modifying lens surfaces in polymerizable compositions, washing polymeric lens bodies in volatile organic solvents or aqueous solutions of volatile organic solvents has also been used to increase the wettability of lens surfaces, particularly silicone hydrogel contact lens surfaces. Although the polymeric lens bodies of the present invention can be washed in a volatile organic solvent or an aqueous solution of a volatile organic solvent in accordance with the present invention, this is not necessary to obtain a hydrogel contact lens having an ophthalmically acceptably wettable lens surface when fully hydrated. In other words, in one example, the hydrogel contact lenses of the invention are not exposed to a volatile organic solvent (including a solution of a volatile organic solvent) as part of the manufacturing process. In one example, the hydrogel contact lenses of the present invention can be formed from a polymerizable composition that does not contain a wetting agent, or the polymerized lens body and/or hydrated contact lens can be free of a wetting agent, or free of a surface treatment, or free of a surface modification, or free of exposure to a volatile organic solvent during the manufacturing process, or any combination thereof. In contrast, for example, the hydrogel contact lens can be washed in a volatile organic solvent-free wash solution (e.g., water or an aqueous solution free of volatile organic solvents, including liquids free of volatile lower alcohols).

The use of volatile organic solvents to extract the lens body significantly increases production costs due to factors such as: the cost of organic solvents, the cost of disposing of solvents, the need to employ explosion proof production equipment, the need to remove solvents from the lens prior to packaging, and the like. However, it can be challenging to develop polymerizable compositions that consistently produce contact lenses having ophthalmically acceptably wettable lens surfaces upon extraction in an aqueous liquid that is free of volatile organic solvents. For example, the presence of unwetted areas is often found on the lens surface of contact lenses that have been extracted in aqueous liquids that are free of volatile organic solvents.

As previously discussed, in one example of the invention, the contact lens is one that has not been exposed to volatile organic solvents (e.g., lower alcohols) during manufacture. In other words, the washing, extraction and hydration liquids used for the lenses and all liquids used in wet demolding, or wet delensing, or washing, or any other manufacturing step are free of volatile organic solvents. In one example, the polymerizable composition used to form these lenses that are not in contact with volatile organic solvents can comprise a hydrophilic vinyl-containing monomer or monomer component, e.g., a hydrophilic vinyl ether-containing monomer. The vinyl-containing hydrophilic monomer or monomer component can include, for example, VMA. The vinyl ether containing monomer may include, for example, BVE, or EGVE, or DEGVE, or any combination thereof. In a particular example, the vinyl ether-containing monomer can be a vinyl ether-containing monomer that is more hydrophilic than BVE, e.g., DEGVE. In another example, the hydrophilic monomer component in the polymerizable composition can be a mixture of a first hydrophilic monomer that is a vinyl-containing monomer but not a vinyl ether-containing monomer and a second hydrophilic monomer that is a vinyl ether-containing monomer. The mixture includes, for example, a mixture of VMA and one or more vinyl ethers (e.g., BVE, or DEGVE, or EGVE, or any combination thereof).

When present, the hydrophilic vinyl ether-containing monomer or monomer component can be present in the polymerizable composition in an amount of from about 1 to about 15 unit parts, or from about 3 to about 10 unit parts. When present in admixture with a hydrophilic vinyl-containing monomer other than a vinyl ether, the moieties of the hydrophilic vinyl-containing monomer or monomer component other than a vinyl ether and the hydrophilic vinyl ether-containing monomer or monomer component can be present in the polymerizable composition in a ratio of at least 3: 1, or from about 3: 1 to about 15: 1, or about 4: 1, based on the ratio of parts by weight of the hydrophilic vinyl-containing monomer or monomer component other than a vinyl ether to parts by weight of the hydrophilic vinyl ether-containing monomer or monomer component.

Another method of producing the present contact lenses having ophthalmically acceptably wettable lens surfaces, particularly lenses extracted in liquids free of volatile organic solvents and including lenses that are not contacted with volatile organic solvents during manufacture, can be to limit the amount of vinyl-containing crosslinking agent or crosslinker component included in the polymerizable composition. For example, the vinyl-containing crosslinking agent or crosslinker component can be present in the polymerizable composition in an amount of from about 0.01 to about 0.80 unit parts, or from 0.01 to about 0.30 unit parts, or from about 0.05 to about 0.20 unit parts, or in an amount of about 0.1 unit parts. In one example, the vinyl-containing crosslinking agent or crosslinker component can be present in the polymerizable composition in an amount effective to produce a contact lens having enhanced wettability compared to a contact lens produced from the same polymerizable composition but in an amount greater than about 2.0 unit parts, or greater than 1.0 unit parts, or greater than about 0.8 unit parts, or greater than about 0.5 unit parts, or greater than about 0.3 unit parts.

While limiting the amount of vinyl-containing crosslinking agent or crosslinker component can improve wettability, in one example, the inclusion of a vinyl-containing crosslinking agent or crosslinker component in the polymerizable composition can improve the dimensional stability of the resulting contact lens formed from the polymerizable composition. Thus, in some polymerizable compositions, the vinyl-containing crosslinking agent or crosslinker component can be present in the polymerizable in an amount effective to produce a contact lens having improved dimensional stability as compared to a contact lens produced from the same polymerizable composition but without the vinyl-containing crosslinking agent or crosslinker component.

Yet another method of producing contact lenses of the invention having ophthalmically acceptably wettable surfaces, particularly lenses washed in liquids free of volatile organic solvents, can be to include an amount of a vinyl-containing crosslinking agent or crosslinker component in the polymerizable composition based on the ratio of the parts per weight of hydrophilic vinyl-containing monomer or monomer component present in the composition to the parts per weight of vinyl-containing crosslinking agent or crosslinker component present in the composition. For example, the total unit parts of the hydrophilic vinyl-containing monomer or monomer component and the total unit parts of the vinyl-containing crosslinking agent or crosslinker component can be present in the polymerizable composition in a ratio of greater than about 125: 1, or from about 150: 1 to about 625: 1, or from about 200: 1 to about 600: 1, or from about 250: 1 to about 500: 1, or from about 450: 1 to about 500: 1, based on the ratio of the unit parts by weight of all hydrophilic vinyl-containing monomers present in the polymerizable composition to the total unit parts by weight of all vinyl-containing crosslinking agents present in the polymerizable composition.

In one example, the contact lenses of the invention are ophthalmically compatible silicone hydrogel contact lenses. As will be discussed below, many different criteria may be evaluated to determine whether a contact lens is ophthalmically compatible. In one example, an ophthalmically acceptable contact lens has an ophthalmically acceptable wettable surface when fully hydrated. A silicone hydrogel contact lens having an ophthalmically acceptably wettable surface can be understood to refer to a silicone hydrogel contact lens that adversely affects the tear film of the lens wearer's eye to an extent that does not cause the lens wearer to experience or report discomfort associated with placement or wearing of the silicone hydrogel contact lens on the eye.

Examples of the disclosed polymerizable compositions can be miscible at the time of initial preparation and can remain miscible for a period of time sufficient for industrial manufacture of contact lenses (e.g., about 2 weeks, or about 1 week, or about 5 days). Typically, upon polymerization and processing into contact lenses, the miscible polymerizable compositions produce contact lenses having ophthalmically acceptable clarity.

A method commonly used to increase the miscibility of hydrophilic monomers and less hydrophilic or relatively hydrophobic monomers, including silicone monomers, includes adding an organic diluent to the polymerizable composition to act as a compatibilizer between the more hydrophilic and less hydrophilic monomers. For example, siloxane monomers are generally more hydrophobic. Moreover, when using siloxane monomers, miscibility can also be increased by using only siloxane monomers having low molecular weights (e.g., molecular weights below 2500 daltons). In one example where the polymerizable composition comprises a first siloxane and a second siloxane monomer, the use of a first siloxane of formula (6) above allows for the inclusion of both an optional high molecular weight second siloxane and a high level of at least one hydrophilic monomer in the polymerizable composition of the present invention. Moreover, while one or more organic diluents may be included in the polymerizable compositions of the present invention disclosed herein, such may not be necessary to obtain a miscible polymerizable composition of the present invention. In other words, in one example, the hydrogel contact lenses of the invention are formed from a polymerizable composition that is free of organic diluents.

In one example, a silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic amide monomer having at least one N-vinyl group; wherein the polymerizable composition is free of organic diluent and free of DMA; and the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The hydrogel contact lenses of the invention can be provided in a sealed package. For example, the hydrogel contact lenses of the present invention may be provided in sealed blister packages or other similar containers suitable for delivery to lens wearers. The lens can be stored in an aqueous solution (e.g., saline solution) within the package. Some suitable solutions include phosphate buffered saline solutions and borate buffered solutions. The solution may include a disinfectant, if desired, or may be free of a disinfectant or preservative. The solution may also include a surfactant, such as a poloxamer (poloxamer) or the like, if desired.

The lenses in the sealed package are preferably sterile. For example, the lens can be sterilized prior to sealing the package or can be sterilized in a sealed package. The sterilized lens can be a lens that has been exposed to a sterilizing amount of radiation. For example, the lens can be an autoclaved lens, a gamma irradiated lens, a lens exposed to ultraviolet radiation, and the like.

In the case of a contact lens package, the package may further include a base member having a cavity configured to receive the contact lens body and the packaging solution; and a seal attached to the base member, the seal configured to maintain the contact lens and packaging solution under sterile conditions for a duration of time equivalent to the shelf life of the contact lens.

Certain specific examples of silicone hydrogel contact lenses will now be described in accordance with the teachings of the present disclosure.

As one example (example a), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of a polymerizable composition comprising at least one siloxane monomer and at least one hydrophilic monomer. The silicone hydrogel contact lenses have an average equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC). In one example, the at least one monomer comprises a first siloxane monomer represented by formula (3), wherein m in formula (3) represents an integer from 3 to 10, n in formula (3) represents an integer from 1 to 10, and R ¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group. In this example, the silicone hydrogel contact lens comprises a silicone hydrogel contact lens comprising a polymerized lens body that is the reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, such asAs determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

As a second example (example B), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition of example a, and wherein the polymerizable further comprises a second siloxane monomer. In one example, the first siloxane monomer and the second siloxane monomer can be present in a ratio of at least 2: 1 based on the parts by weight of the first siloxane monomer to the parts by weight of the second siloxane monomer present in the polymerizable composition.

As a third example (example C), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as described in examples a or B, and wherein the polymerizable composition further comprises a hydrophobic monomer or monomer component. For example, the hydrophilic monomer may comprise or consist of Methyl Methacrylate (MMA), EGMA, or any combination thereof.

As a fourth example (example D), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as in examples a or B or C, and wherein the polymerizable composition further comprises a vinyl-containing crosslinking agent or crosslinker component. In one example, the crosslinker or crosslinker component can comprise or consist of a vinyl ether-containing crosslinker or crosslinker component, specifically the crosslinker or crosslinker component can comprise or consist of triethylene glycol divinyl ether (TEGVE).

As a fifth example (example E), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as in examples a or B or C or D, and wherein the polymerizable composition further comprises a thermal initiator or thermal initiator component.

As a sixth example (example F), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as described in examples a or B or C or D or E, and wherein at least one hydrophilic monomer comprises a hydrophilic monomer component comprising a first hydrophilic monomer and a second hydrophilic monomer. In one example, the first hydrophilic monomer can comprise a hydrophilic amide-containing monomer and the second hydrophilic monomer can comprise a vinyl ether-containing monomer.

As a seventh example (example G), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as in examples a or B or C or D or E or F, and wherein the polymerizable composition further comprises a UV absorber or UV absorber component.

As an eighth example (example H), a silicone hydrogel contact lens comprises a polymeric lens body that is the reaction product of the polymerizable composition as in examples a or B or C or D or E or F or G, and wherein the polymerizable composition further comprises a colorant or a colorant component.

As a ninth example (example I), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as in examples a or B or C or D or E or F or G or H, and wherein the polymerizable composition comprises a siloxane monomer represented by formula (2), wherein R in formula (2) ₁Selected from a hydrogen atom or a methyl group; r in the formula (2)₂Selected from hydrogen or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (2) represents an integer of 0 to 10; n in formula (2) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration. As an example, the siloxane monomer may be represented by formula (2), wherein m in formula (2) is 0, n in formula (2) is an integer of 5 to 10, a is an integer of 65 to 90, b is an integer of 1 to 10Integer, R in formula (2)₁Is methyl, and R in formula (2)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms.

As a tenth example (example J), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as in examples a or B or C or D or E or F or G or H or I, and wherein the polymerizable composition further comprises a methacrylate-containing crosslinker or crosslinker component, in particular the crosslinker or agent component can comprise or consist of Ethylene Glycol Dimethacrylate (EGDMA). In this example, where the polymerizable composition also includes a vinyl ether-containing crosslinker as part of the crosslinker component, specifically the crosslinker component can comprise or consist of a combination of triethylene glycol divinyl ether (TGDVE) and a methacrylate-containing crosslinker, which can specifically comprise or consist of Ethylene Glycol Dimethacrylate (EGDMA). In this example, it can be appreciated that the polymerizable composition comprises two crosslinkers, each having a different reactivity ratio, i.e., the polymerizable composition contains a crosslinker component comprising or consisting of a vinyl-containing crosslinker and a methacrylate-containing crosslinker having polymerizable functional groups that are more reactive and therefore react at a faster rate than the vinyl-containing polymerizable functional groups present in the vinyl-containing crosslinker.

As an eleventh example (example K), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable composition as in examples a or B or C or D or E or F or G or H or I or J, and wherein the polymerizable composition further comprises a chain transfer agent or chain transfer agent component that specifically can comprise or consist of Allyloxyethanol (AE).

As a twelfth example (example L), a silicone hydrogel contact lens comprises a polymeric lens body that is the reaction product of the polymerizable composition as described in examples a or B or C or D or E or F or G or H or I or J or K, and wherein at least one hydrophilic monomer comprises a hydrophilic vinyl ether-containing monomer or monomer component, e.g., the hydrophilic vinyl ether-containing monomer or monomer component can comprise or consist of 1, 4-Butanediol Vinyl Ether (BVE), or Ethylene Glycol Vinyl Ether (EGVE), or diethylene glycol vinyl ether (DEGVE), or any combination thereof.

As a thirteenth example (example M), a silicone hydrogel contact lens comprises a polymerized lens body that is the reaction product of the polymerizable compositions as described in examples a or B or C or D or E or F or G or H or I or J or K or L, wherein the contact lens has an ophthalmically acceptably wettable lens surface when the polymerizable composition used to form the lens does not contain an internal wetting agent, or when the polymerizable composition used to form the polymerized lens body does not contain an organic diluent, or when the polymerized lens body is extracted in a liquid that does not contain a volatile organic solvent, or when the lens is not surface plasma treated, or any combination thereof.

In any or each of the above examples a-M, as well as any or all other examples disclosed herein, the amount of the first siloxane monomer can be from 20 to 45 unit parts of the polymerizable composition. The amount of the first siloxane monomer can be from 25 to 40 unit parts of the polymerizable composition. The amount of the first siloxane monomer can be 27 to 35 unit parts of the polymerizable composition.

In any or each of the above examples a-M, as well as any or all of the other examples disclosed herein, the amount of the optional second siloxane monomer can comprise 1 to 20 unit parts of the polymerizable composition. The amount of the second siloxane monomer can be from 2 to 15 unit parts of the polymerizable composition. The amount of the second siloxane monomer can be from 5 to 13 unit parts of the polymerizable composition. In another example, the ratio of unit parts of the first siloxane monomer to the second siloxane can be at least 1: 1, or at least 2: 1.

In any or each of the above examples a-M, as well as any or all other examples disclosed herein, where the at least one siloxane monomer comprises a siloxane monomer component consisting of a first siloxane monomer and a second siloxane monomer, the amount of the first siloxane monomer can comprise 20 to 45 unit parts of the polymerizable composition. The amount of the first siloxane monomer can be from 25 to 40 unit parts of the polymerizable composition. The amount of the first siloxane monomer can be 27 to 35 unit parts of the polymerizable composition.

In any or each of the above examples a-M, as well as any or all other examples disclosed herein, where the at least one siloxane monomer comprises a siloxane monomer component consisting of a first siloxane monomer and a second siloxane monomer, the amount of the second siloxane monomer can comprise 1 to 20 unit parts of the polymerizable composition. The amount of the second siloxane monomer can be from 2 to 15 unit parts of the polymerizable composition. The amount of the second siloxane monomer can be from 5 to 13 unit parts of the polymerizable composition. In another example, the ratio of unit parts of the first siloxane monomer to the second siloxane can be at least 1: 1, or at least 2: 1, or at least 4: 1, or about 4: 1.

In any or each of the above examples a-M, as well as any or all of the other examples disclosed herein, the amount of hydrophilic monomer or monomer component present in the polymerizable composition can be from 1 to 60 unit parts of the polymerizable composition. The hydrophilic monomer component can comprise from 4 to 60 unit parts of the polymerizable composition. Where the hydrophilic monomer comprises or consists of VMA, it can be present in an amount of 30 unit parts to 60 unit parts. The VMA can be present in the polymerizable composition in an amount of about 40 unit parts to about 50 unit parts. Where a hydrophilic monomer (i.e., N-Dimethylacrylamide (DMA), 2-hydroxyethyl methacrylate (HEMA), or 2-hydroxybutyl methacrylate (HOB), or any combination thereof) is present in the polymerizable composition as the hydrophilic monomer in the hydrophilic monomer component, each or all may be present in an amount of about 3 to about 10 unit parts.

In any or each of the above examples a-M, as well as any or all of the other examples disclosed herein, the hydrophobic monomer or monomer component can be present in the polymerizable composition in an amount of 1 to 30 unit parts of the polymerizable composition. For example, the total amount of hydrophobic monomer or monomer component can be from about 5 to about 20 unit parts of the polymerizable composition. In polymerizable compositions where the hydrophobic monomer MMA is present as a hydrophobic monomer or as part of a hydrophobic monomer component, MMA may be present in amounts of from about 5 to about 20 unit parts, or from about 8 to about 15 unit parts.

In any or each of the above examples a-M, as well as any or all of the other examples disclosed herein, the crosslinker or crosslinker component can be present in the polymerizable composition in an amount from 0.01 to 4 unit parts of the polymerizable composition. TEGDVE may be present in an amount of 0.01 to 1.0 unit parts. EGDMA may be present in an amount of 0.01 to 1.0 unit parts. TEGDMA may be present in an amount of 0.1 to 2.0 unit parts. Each of these silicon-free crosslinkers can be present in the polymerizable composition alone or in any combination.

In any or each of the above examples a-M, as well as any or all of the other examples disclosed herein, when the polymerizable composition contains EGMA, BVE, DEGVE, EGVE, or any combination thereof, they can each be present in an amount from 1 unit part to 20 unit parts of the polymerizable composition. EGMA may be present in an amount of about 2 unit parts to about 15 unit parts. BVE can be present in an amount of from 1 unit part to about 15 unit parts. BVE can be present in an amount of about 3 unit parts to about 7 unit parts. DEGVE may be present in an amount of 1 unit part to about 15 unit parts. DEGVE may be present in an amount of about 7 unit parts to about 10 unit parts. EGVE may be present in an amount of from 1 unit part to about 15 unit parts, or in an amount of from about 3 unit parts to about 7 unit parts.

In any or each of the above examples a-M, as well as in any or all of the other examples disclosed herein, other optional components (e.g., an initiator or initiator component, a colorant or colorant component, a UV absorber or UV absorber component, an oxygen scavenger or oxygen scavenger component, or a chain transfer agent or chain transfer agent component) can each be present in an amount of from about 0.01 unit parts to about 3 unit parts. The initiator or initiator component may be present in the polymerizable in an amount of from 0.1 unit parts to 1.0 unit parts. When present, the thermal initiator or thermal initiator component (e.g., Vazo-64) may be present in an amount of from about 0.3 to about 0.5 unit parts. The colorant or colorant component may be present in an amount of from 0.01 unit parts to 1 unit part. When a reactive dye (e.g., reactive blue 246 or reactive blue 247) is used as a colorant or as part of a colorant component, it can each be present in an amount of about 0.01 unit parts. The UV absorber or UV absorber component can be present in an amount of 0.1 unit parts to 2.0 unit parts. For example, the UV absorber UV1 described in examples 1-4 below may be present in an amount of about 0.8 to about 1.0 unit parts (e.g., 0.9 unit parts); or the UV absorber UV2 described in examples 1-4 below may be present in an amount of 0.5 unit parts to 2.5 unit parts (e.g., about 0.9 unit parts to about 2.1 unit parts). The oxygen scavenger or oxygen scavenger component may be present in an amount of from 0.1 unit parts to 1.0 unit parts. By way of example, where Triphenylphosphine (TPP) or diphenyl (p-vinylphenyl) phosphine (pTPP), or any combination thereof, is used as the oxygen scavenger or oxygen scavenger component in the polymerizable composition, each or combination may be present in an amount of from 0.3 unit parts to 0.7 unit parts, for example, about 0.5 unit parts. The chain transfer agent or chain transfer agent component may be present in the polymerizable composition in an amount of from 0.1 unit parts to 2.0 unit parts, and in many of examples 1-4 below in an amount of from 0.2 unit parts to 1.6 unit parts. For example, the chain transfer agent Allyloxyethanol (AE) may be present in an amount of about 0.3 to about 1.4 unit parts.

In any or each of the above examples a-M, as well as in any or all other examples disclosed herein, the silicone hydrogel contact lens can be free of a wetting agent present in the polymerizable composition, or present in the polymerized lens body, or present in the silicone hydrogel contact lens. Similarly, silicone hydrogel contact lenses can have lens surfaces that are not surface treated or surface modified. However, in another example, the silicone hydrogel contact lens can include at least one wetting agent (i.e., a single wetting agent or two or more wetting agents present as wetting agent components) in the polymerizable composition, in the polymerized lens body, or in the silicone hydrogel contact lens. Silicone hydrogel contact lenses may have treated or modified lens surfaces. Additionally or alternatively, any or each of the foregoing examples a-M, as well as any or all other examples of the silicone hydrogel contact lenses disclosed herein, the contact lenses can be understood to be free of a linking agent (e.g., an organoboronic acid form).

In another example, novel polymerizable compositions are provided, including each of the (each and every) polymerizable compositions described herein with reference to the silicone hydrogel contact lenses and methods. The polymerizable composition can be free of diluents, in that it is free of organic solvents (e.g., alcohols, etc.), which can help reduce phase separation of the polymerizable composition. However, the diluent-free polymerizable composition may still contain one or more chain transfer agents, such as allyloxyethanol. However, if desired, the polymerizable composition can include a diluent or diluent component, which can be present in an amount of 1 to 20 unit parts.

As described herein, the silicone hydrogel contact lenses of the invention, when fully hydrated, have an average Equilibrium Water Content (EWC) of from about 30% wt/wt to about 70% wt/wt, or an average oxygen permeability of at least 55 barrers, or an average captive bubble dynamic advancing contact angle of less than 70 degrees, or an average captive bubble static contact angle of less than 55 degrees, or any combination thereof, based on an average of the values determined for at least 20 individual lenses in a batch, comprising a polymeric lens body comprising units derived from at least one siloxane monomer and at least one hydrophilic monomer. Accordingly, the present invention also relates to a batch of silicone hydrogel contact lenses.

In one example, the batch of silicone hydrogel contact lenses comprises a plurality of silicone hydrogel contact lenses, each silicone hydrogel contact lens comprising a polymerized lens body that is a reaction product of a polymerizable composition comprising (a) at least one siloxane monomer; and (b) at least one hydrophilic monomer; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

As used herein, a batch of silicone hydrogel contact lenses refers to a set of two or more silicone hydrogel contact lenses, and typically, a batch refers to at least 10, or at least 100, or at least 1,000 silicone hydrogel contact lenses. According to the present invention, a batch of silicone hydrogel contact lenses comprises a plurality of any of the silicone hydrogel contact lenses described herein.

As used herein, a batch of hydrogel contact lenses refers to a set of two or more hydrogel contact lenses, and typically, a batch refers to at least 10, or at least 100, or at least 1,000 hydrogel contact lenses. According to the present invention, a batch of hydrogel contact lenses comprises a plurality of any of the hydrogel contact lenses described herein.

In one example, a batch of hydrogel contact lenses can have an average Axial Edge Lift (AEL) difference based on averaging the AEL measurements for a representative number of lenses in the batch at different time points. For a batch of lenses, a mean AEL difference of less than +/-100% (± 100%), or less than +/-50% (± 50%), or less than 20% (± 20%) may be considered acceptable over a period of two weeks to seven years at room temperature, or when stored at a time period and temperature equivalent to storage at room temperature for two weeks to seven years under accelerated shelf life testing conditions. In one example, an accelerated shelf life test condition particularly useful for determining average AEL difference is 4 weeks at 70 ℃, although other time periods and temperatures may be used. The average AEL difference is determined by the time of storage at room temperature or at accelerated shelf life conditions (AEL) _Initial) And thereafter (AEL_{Finally, the product is processed}) The AEL values for each representative lens were averaged using actual AEL measurements for the representative lens to determine. The average AEL variability was determined using the following equation (C):

((AEL_{finally, the product is processed}-AEL_Initial)/AEL_Initial)×100(C)。

On average, the batch of hydrogel contact lenses has a change in AEL of less than 20% in either direction of the target value, or less than 10% in either direction of the target value, or less than 5% in either direction of the target value. As one example, if the contact lenses have a target AEL of 20 μm ± 50%, the present batch of hydrogel contact lenses will have an average AEL of 10 μm to 30 μm during the shelf life study procedure. The representative number of lenses tested in the batch may be 20 or more than 20 individual lenses.

In an accelerated shelf life study, the lens properties (e.g., AEL or color value) of a contact lens that has been stored at elevated temperatures (e.g., greater than 40 ℃, such as 50 ℃, or 55 ℃, or 65 ℃, or 70 ℃, or 80 ℃, or 95 ℃, etc.) for a period of time can be determined. Alternatively, the lens properties of a contact lens that has been stored at room temperature (e.g., about 20 ℃ to 25 ℃) for a period of time can be determined.

For accelerated shelf life studies, the number of storage months at a particular temperature corresponding to a desired length of storage at room temperature can be determined using the following formula (D):

Desirable shelf life ═ N × 2y ] + N (d)

Wherein

N-number of months stored under accelerated conditions

2 y-acceleration factor

y 2.0 (for every 10 ℃ above room temperature (25 ℃), for storage at 45 ℃ or above 45 ℃)

y 1.0 (for every 10 ℃ above room temperature (25 ℃), for storage at 35 ℃ to 45 ℃)

n-the age of the lens at the start of the study (in months).

Based on this equation, the following storage times have been calculated: storage at 35 ℃ for 6 months corresponds to aging at 25 ℃ for 1 year, storage at 45 ℃ for 3 months corresponds to aging at 25 ℃ for 1 year, storage at 55 ℃ for 3 months corresponds to aging at 25 ℃ for 2 years, and storage at 65 ℃ for 3 months corresponds to aging at 25 ℃ for 4 years.

In one example, the batch comprises a batch of silicone hydrogel contact lenses comprising a plurality of the silicone hydrogel contact lenses of the invention, wherein the batch of silicone hydrogel contact lenses has at least two average values based on the average values determined for at least 20 individual lenses in the batch selected from the group consisting of: an average oxygen permeability of at least 55 barrers, an average tensile modulus of from about 0.2MPa to about 0.9MPa when fully hydrated, and an average EWC of from about 30% wt/wt to about 70% wt/wt.

In one example, a batch of lenses may exhibit a change in average physical dimension when first tested shortly after manufacture and then tested again at a subsequent point in time. Where multiple batches of lenses of the invention are dimensionally stable, they may exhibit an acceptable level of variation in average physical dimension. As used herein, dimensional stability difference is understood to mean the difference in physical dimension value between the physical dimension value determined when the batch of lenses is first tested shortly after their manufacture and the physical dimension value when the batch of lenses is tested again at a subsequent point in time. The subsequent time point can be, for example, at least 2 weeks after the initial time point to as long as 7 years after the initial time point. The batches of silicone hydrogel contact lenses have a mean dimensional stability difference of less than +/-3% (± 3.0%) based on averaging lens diameter measurements for a representative number of lenses in the batch (e.g., 20 lenses in the batch). For a batch of lenses, a mean dimensional stability difference of less than +/-3% (± 3.0%) is considered a dimensionally stable batch, wherein the mean dimensional stability difference is the initial dimensional stability difference within one day of the manufacture date of the batch of lenses The difference in the physical dimension value between when measured at the starting point in time and when measured at a second point in time (where the second point in time is two weeks to seven years after the starting point in time when the batch is stored at room temperature; or when the batch is stored at a higher temperature (i.e., under accelerated shelf life testing conditions), the second point in time is a point in time representing two weeks to seven years of storage of the batch at room temperature). In one example, an accelerated shelf life test condition that is particularly useful for determining the difference in average dimensional stability is 4 weeks at 70 ℃, although other time periods and other temperatures may be used. The mean dimensional stability difference is the actual diameter (diameter) of a representative lens using the first measurement_Initial) And the actual diameter (diameter) of a representative lens measured at room temperature or after storage under accelerated shelf life conditions_{Finally, the product is processed}) Determined by averaging the individual dimensional stability differences for each representative lens. The representative lens measured for the first time and the representative lens measured after storage may be the same lens or may be different lenses. The average dimensional stability difference as used herein is expressed in percent (%). The individual dimensional stability differences were determined using the following equation (E):

((diameter)_{Finally, the product is processed}Diameter of_Initial) Diameter_Initial)×100(E)。

On average, the batch of silicone hydrogel contact lenses varied in diameter by less than 3% (± 3.0%) in either direction of the target value. As one example, if the contact lens has a target diameter (chord diameter) of 14.20mm, the present batch of silicone hydrogel contact lenses will have an average diameter (average of the population in the batch) of 13.77mm to 14.63 mm. In one example, the dimensional stability difference is less than +/-2% (+ -2.0%). As one example, if the contact lens has a target diameter (chord diameter) of 14.20mm, the present batch of silicone hydrogel contact lenses will have an average diameter (average of the population in the batch) of 13.92mm to 14.48 mm. Preferably, the mean diameter of the batch of silicone hydrogel contact lenses does not vary more than +/-0.20mm from the target diameter (typically 13.00mm to 15.00 mm).

In an accelerated shelf life study, the difference in average dimensional stability of contact lenses that have been stored at elevated temperatures (e.g., above 40 ℃, including, for example, 50 ℃, or 55 ℃, or 65 ℃, or 70 ℃, or 80 ℃, or 95 ℃, etc.) for a period of time can be determined. Alternatively, the average dimensional stability of a contact lens that has been stored at room temperature (e.g., about 20 ℃ to 25 ℃) for a period of time can be determined.

Another example of the present invention provides a method of making a hydrogel contact lens. According to the teachings of the present disclosure, the method comprises providing a polymerizable composition.

In one example, the method is a method comprising the steps of: providing a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The method can further comprise the step of polymerizing the polymerizable composition to form a polymerized lens body. The step of polymerizing the polymerizable composition can be carried out in a contact lens mold assembly. The polymerizable composition can be cast molded between molds formed from thermoplastic polymers. The thermoplastic polymer used to form the molding surface of the mold may comprise a polar polymer, or may comprise a non-polar polymer. Alternatively, the polymerizable composition can be formed into a lens via various methods known to those skilled in the art, such as spin casting, injection molding, forming a polymeric rod, and then lathing to form a lens body, and the like.

In one example, the method is a method comprising the steps of: providing a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the polymerizing step comprises polymerizing the polymerizable composition in a contact lens mold assembly having a molding surface formed from a non-polar thermoplastic polymer to form a polymerized lens body, and wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Polymerization of the polymerizable composition can be initiated thermally or using light, for example using Ultraviolet (UV) light. In some examples, the polymerization may be carried out in an atmosphere comprising air or in an inert atmosphere.

In one example, the method is a method comprising the steps of: providing a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, the method is a method comprising the steps of: providing a polymerizable composition comprising: (a) a first siloxane monomer represented by formula (1):

wherein n in formula (1) is 0 to 30, or 10 to 15; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS) and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, the method is a method comprising the steps of: providing a polymerizable composition comprising: (a) a first siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In yet another example, the method is a method comprising the steps of: providing a polymerizable composition comprising: (a) a first siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein F is the calorific value of pure water in melting and is expressed by J/g. In this example, the hydrophilic monomer can optionally comprise a hydrophilic amide monomer having one N-vinyl group, or the polymerizable composition can be free of DMA, or the polymerizable composition can be free of an organic diluent, or any combination thereof.

The method can also include the step of demolding the polymeric lens body from one mold portion for cast molding the lens body, or delensing the polymeric lens body from two mold portions for cast molding the lens body, or both. In one example, the step of demolding the lens body, or delensing the lens body, or both, can be performed mechanically, i.e., without contacting the polymeric lens body with a liquid during the demolding/delensing process.

In one example, the method is a method comprising the steps of: providing a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; and contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein n in formula (1) is 0 to 30, or 10 to 15; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS) and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymerized contact lens body with a cleaning solutionTo remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, such as by As determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymeric contact lens body with a wash solution to remove the polymeric contact lens body from the polymeric contact lens Removing the extractable material from the eyewear lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

The method can also include contacting the polymeric lens body with a washing solution to remove extractable materials, such as unreacted monomers, uncrosslinked materials that were not physically immobilized in the polymeric lens body, diluents, and the like. The wash liquid may be a liquid that is free of volatile organic solvents, or may comprise a volatile organic solvent (e.g., may be a volatile organic solvent or a solution of a volatile organic solvent).

In one example, the method is a method comprising the steps of: providing a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; and contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Wherein n in formula (1) is 0 to 30, or 10 to 15; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS) and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

Wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, the method is a method comprising the steps of: providing a polymerizable composition comprising: (a) a first siloxane monomer represented by formula (4):

Wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; in the formula (4)M of (a) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

In another example, the method is a method comprising the steps of: providing a polymerizable composition comprising (a) at least one siloxane monomer, and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; and contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein n in formula (1) is 0 to 30, or 10 to 15; (b) 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate (TRIS) and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration; and (b) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group; and (c) at least one hydrophilic monomer; polymerizing the polymerizable composition in a contact lens mold assembly under an atmosphere consisting essentially of air to form a polymeric lens body; mechanically demolding and delensing the polymeric lens body; contacting the polymeric contact lens body with a washing solution free of volatile organic solvents to remove extractable material from the polymeric contact lens body; and packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package; wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by Differential Scanning Calorimetry (DSC); and the equilibrium freezable water content is calculated using equation (a):

As previously discussed, the wash solution may be water or an aqueous solution without a volatile organic solvent, or may be an organic solvent or a solution of an organic solvent. Alternatively, in some examples, the method does not comprise the step of contacting the polymeric lens body with a washing solution or any liquid, i.e., wherein the polymeric lens body is not contacted with any liquid prior to placing the polymeric lens body in a blister package containing the packaging solution and sealing. The method can be a method that does not include a washing step involving the use of a washing liquid comprising a volatile organic solvent, i.e., wherein the polymeric lens body is contacted with the washing liquid, but not with the washing liquid comprising the volatile organic solvent, and not with the volatile organic solvent prior to placing the polymeric lens body in a blister package containing the packaging solution and sealing.

In a method comprising the step of contacting the lens body with a washing liquid, the step of contacting the polymeric lens body with a washing liquid may be understood as an extraction step, since extractable material is removed from the polymeric lens body. In some methods, the contacting step comprises contacting the polymeric lens body with a wash solution comprising a volatile organic solvent, such as a liquid comprising a primary alcohol (e.g., methanol, ethanol, n-propanol, etc.). Some wash solutions may contain secondary alcohols such as isopropanol and the like. The use of a wash solution containing one or more volatile organic solvents can aid in the removal of hydrophobic materials from the polymeric lens body and thereby can increase the wettability of the lens surface. The process can be understood as an alcohol-based extraction step. In other methods, the contacting step comprises contacting the polymeric lens body with an aqueous wash solution that is free of volatile organic solvents. The process may be understood as an aqueous extraction step. Examples of aqueous wash solutions that can be used in the method include water (e.g., deionized water), saline solutions, buffer solutions, or aqueous solutions containing surfactants or other non-volatile ingredients that can improve removal of hydrophobic components from, or can reduce deformation of, a polymeric contact lens body compared to using deionized water alone. In one example, the surface of the lens body of the present invention has an ophthalmically acceptably wettable surface when washed with a wash solution that is free of volatile organic solvents.

After washing, the contact lens can be placed in a package (e.g., a plastic blister package) containing a packaging solution (e.g., a buffered saline solution), which may or may not contain surfactants, anti-inflammatory agents, antimicrobial agents, contact lens wetting agents, and the like; and sealed and sterilized. The packaging solutions used to package the silicone hydrogel contact lenses of the present invention may include a wetting agent to increase the wettability of the lens surface. However, it should be understood that the lens surface of the silicone hydrogel contact lenses of the present invention has an ophthalmically acceptably wettable surface prior to contact with a packaging solution comprising a wetting agent, and that the wetting agent is used in the packaging solution only to increase the wettability of a surface that is already ophthalmically acceptably wettable, and thus, there is no need to provide an ophthalmically acceptably wettable surface to the contact lens.

After washing, the contact lens can be placed in a package (e.g., a plastic blister package) containing a packaging solution (e.g., a buffered saline solution), which may or may not contain surfactants, anti-inflammatory agents, antimicrobial agents, contact lens wetting agents, and the like; and can be sealed and sterilized.

According to the present invention, the polymeric lens body can be packaged in a contact lens package (e.g., a blister package or a glass vial) with a contact lens packaging solution. After packaging, the package can be sealed and the polymeric lens body and contact lens packaging solution sterilized, for example, by autoclaving the sealed package, to produce a silicone hydrogel contact lens product.

The present methods can further comprise repeating the steps to produce a plurality of hydrogel contact lenses. The present methods may further comprise manufacturing a batch of hydrogel contact lenses.

Examples of the invention

The following examples 1-4 illustrate certain aspects and advantages of the present invention, which should not be construed as limiting.

The following chemicals are mentioned in examples 1 to 4 and may be mentioned by their abbreviations.

Si 1: 2-methyl-2- [3- (9-butyl-1, 1, 3, 3, 5, 5, 7, 7, 9, 9-decamethylpentasiloxane-1-yl) propoxy ] ethyl 2-acrylate (CAS number 1052075-57-6). (Si1 was obtained as product number X-22-1622 from Shin-Etsu Chemical Co., Ltd., Tokyo, Japan (Japan)).

Si 2: α, ω -bis (methacryloxypropyl) -poly (dimethylsiloxane) -poly (ω -methoxy-poly (ethyleneglycol) propylmethylsiloxane) (the synthesis of this compound can be carried out as described in US20090234089, which is incorporated herein by reference)

VMA: N-vinyl-N-methylacetamide (CAS number 003195786)

DMA: n, N-dimethylacrylamide (CAS number 2680-03-7)

EGMA: ethylene glycol methyl ether methacrylate (CAS number 6976-93-8)

MMA: methyl methacrylate (CAS number 80-62-6)

EGDMA: ethylene glycol dimethacrylate (CAS number 97-90-5)

TEGDMA: triethylene glycol dimethacrylate (CAS number 109-16-0)

BVE: 1, 4-butanediol vinyl Ether (CAS number 17832-28-9)

DeGVE: diethylene glycol vinyl ether (CAS number 929-37-3)

TEGDVE: triethylene glycol divinyl ether (CAS number 765-12-8)

AE: 2-allyloxyethanol (CAS number 111-45-5)

V-64: 2, 2' -azobis-2-methylpropanenitrile (CAS number 78-67-1)

UV 2: methacrylic acid 2- (3- (2H-benzotriazol-2-yl) -4-hydroxy-phenyl) ethyl ester (CAS number 96478-09-0)

RBT 1: 1, 4-bis [4- (2-methacryloyloxyethyl) phenylamino ] anthraquinone (CAS No. 121888-69-5)

RBT 2: 1, 4-bis [ (2-hydroxyethyl) amino ] -9, 10-anthracenedione bis (2-propenoic acid) ester (CAS registry number 109561071)

TPP: triphenylphosphine (CAS number 603-35-0)

pTPP: polymerizable TPP: diphenyl (p-vinylphenyl) phosphine (CAS number 40538-11-2)

Silicone hydrogel contact lens manufacturing and testing procedures

For each example, the chemical compounds described in examples 1-4 were weighed out in amounts corresponding to the unit parts and combined to form a mixture. The mixture was filtered into a bottle through a 0.2 to 5.0 micron syringe filter. The mixture was stored for a maximum of about 2 weeks. The mixture is understood to be a polymerizable silicone hydrogel contact lens precursor composition, or a polymerizable composition as used herein. In examples 1 to 4, the amounts of the listed ingredients are given in parts by weight per unit weight of the polymerizable composition.

A volume of polymerizable composition is cast molded by placing the composition in contact with the lens defining surface of the female mold member. In all of the following examples 1 to 4, the molding surface of the female mold member was formed of a nonpolar resin, specifically, polypropylene. The male mold member is placed in contact with the female mold member to form a contact lens mold assembly comprising a contact lens shaped cavity containing a polymerizable composition. In the following examples 1 to 4, the molding surface of the male mold member was formed of a nonpolar resin, specifically, polypropylene.

The contact lens mold assembly was placed in a nitrogen-purged oven to thermally cure the precursor composition. For all examples 1-4, the contact lens mold assembly is exposed to a temperature of at least about 55 ℃ for about 2 hours. Examples of curing profiles that can be used to cure the silicone hydrogel contact lenses described herein include exposing the contact lens mold assembly to a temperature of 55 ℃ for 40 minutes, to 80 ℃ for 40 minutes, and to 100 ℃ for 40 minutes. Other contact lenses may be manufactured with the same curing profile, but instead of using a first temperature of 55 ℃, which may be 65 ℃.

After polymerizing the polymerizable composition, the contact lens mold assembly is demolded to separate the male and female mold members. The polymeric lens body remains attached to the male or female mold. A dry demolding process that does not contact the mold assembly with a liquid medium may be used, or a wet demolding process that contacts the mold assembly with a liquid medium (e.g., water or an aqueous solution) may be used. Mechanical dry demolding methods may involve applying mechanical force to a portion of one or both mold members to separate the mold members. In all of the following examples 1 to 4, a dry demolding process was used.

The polymeric lens body is then delensed from the male or female mold to produce a delensed polymeric lens body. In one example of a delensing process, a polymeric lens body can be delensed from a male mold member using a dry delensing process by: for example, manually stripping the lens from the male mold member; or compressing the male mold member and directing gas to the male mold member and the polymeric lens body and lifting the dry polymeric lens body from the male mold member with a vacuum device and discarding the male mold member. In other methods, the polymeric lens body can be delensed using a wet delensing process by contacting the dry polymeric lens body with a liquid release medium (e.g., water or an aqueous solution). For example, the male mold member with the polymeric lens body attached thereto can be immersed in a container containing a liquid until the polymeric lens body is separated from the male mold member. Alternatively, a volume of liquid release medium may be added to the female mold to soak the polymeric lens body in the liquid and separate the lens body from the female mold member. In the following examples 1 to 4, a dry delensing method was used. After separation, the lens body can be manually lifted from the mold member using tweezers or using a vacuum device and placed in a tray.

The delensed lens product is then washed to remove extractable material from the polymeric lens body, and the product is hydrated. The extractable material includes polymerizable components (e.g., monomers, or crosslinkers, or any optional polymerizable ingredients (e.g., colorants or UV blockers), or combinations thereof) present in the polymerizable composition that remain in the polymerized lens body in unreacted form, in partially reacted form, or in uncrosslinked form, or any combination thereof, after polymerization of the lens body and prior to extraction of the lens body. The extractable material can also include any non-polymerizable ingredients present in the polymerizable composition, such as any optional non-polymerizable colorant, or UV blocker, or diluent, or chain transfer agent, or any combination thereof, that remains present in the polymerized lens body after polymerization of the polymerized lens body and prior to extraction of the polymerized lens body.

In another method (e.g., a method involving delensing by compressing a male mold member and directing a flow of gas toward the male mold member), a delensed polymeric contact lens body can be placed in a cavity of a lens carrier or tray, wherein the delensed polymeric lens body can then be contacted with one or more volumes of an extraction fluid (e.g., an aqueous extraction fluid without a volatile organic solvent (e.g., deionized water or an aqueous solution of a surfactant such as Tween 80(Tween 80)), or an organic solvent-based extraction fluid (e.g., ethanol), or an aqueous solution of a volatile organic solvent (e.g., ethanol)).

In other methods, such as those involving wet delensing by contacting the mold and lens with a liquid release medium, the delensed polymeric contact lens body can be washed with a wash solution free of volatile organic solvents, such as lower alcohols, e.g., methanol, ethanol, or any combination thereof, to remove extractable components from the lens body. For example, the delensed polymeric contact lens body can be washed by contacting the lens body with an aqueous wash solution free of volatile organic solvents (e.g., deionized water, or a surfactant solution, or a saline solution, or a buffer solution, or any combination thereof) to remove extractable components from the lens body. The washing may be performed in the final contact lens package, or may be performed in a wash tray or wash tank.

In examples 1-4 below, after the dry demolding and dry delensing steps, the dry delensing lens body is placed in a cavity of a tray, and the delensing polymeric lens body is extracted and hydrated by contacting the polymeric lens body with one or more volumes of an extraction solution. The extraction and hydration liquid used in the extraction and hydration process is composed of: a) a combination of a volatile organic solvent-based extraction liquid and a volatile organic solvent-free hydration liquid, or b) a volatile organic solvent-free extraction and hydration liquid, i.e. a completely water-based extraction and hydration liquid. Specifically, in example 1 below, the extraction and hydration process comprises, in order, at least two extraction steps performed in separate portions of ethanol, at least one extraction step performed in a 50: 50wt/wt ethanolic: aqueous portion of tween 80, at least three extraction and hydration steps performed in separate portions of a deionized water solution of tween 80, wherein each extraction step or extraction and hydration step lasts from about 5 minutes to 3 hours. In the following examples 2 to 4, the extraction and hydration procedure used comprised at least three extraction and hydration steps carried out in separate portions of a deionized water solution of tween 80, wherein the temperature of the tween 80 solution portion ranges from room temperature to about 90 ℃, and wherein each extraction and hydration step lasts from about 15 minutes to about 3 hours.

The washed, extracted and hydrated lenses are then individually placed in contact lens blister packages containing a phosphate buffered saline packaging solution. The blister pack is sealed and sterilized by autoclaving.

After sterilization, lens properties such as contact angle (including dynamic and static contact angles), oxygen permeability, ion flux, modulus, elongation, tensile strength, water content, and the like are determined as described herein.

As described in examples 1-4 below, contact lenses of formulations 1-4 were prepared and tested to determine their water content. Commercially available silicone hydrogel contact lenses were also tested to determine their water content.

The Equilibrium Water Content (EWC) of the lenses of the invention can be determined using conventional methods known to those skilled in the art. For the lenses in examples 1-4 below, as well as commercial lenses compared to examples 1-4, the hydrated silicone hydrogel contact lenses were equilibrated in deionized water for at least 30 minutes, and rinsed with at least 3 volumes of deionized water to remove any residual packaging solution from the lenses. The lenses were then removed from the water, wiped to remove excess surface water, and weighed. The weighed lenses can then be dried in an oven at 80 ℃ and under vacuum, and the dried lenses are then weighed. The weight difference was determined by subtracting the weight of the dry lens from the weight of the hydrated lens. The water content (% wt/wt) is (weight difference/hydrated weight) × 100.

The equilibrium freezable water content and equilibrium non-freezable water content of the lenses of the invention can be determined using conventional methods known to those skilled in the art. For the lenses in examples 1-4 below, as well as commercial lenses compared to examples 1-4, the hydrated silicone hydrogel contact lenses were equilibrated in deionized water for at least 30 minutes, and rinsed with at least 3 volumes of deionized water to remove any residual packaging solution from the lenses. The lens was then removed from the water, wiped to remove excess surface water, and the sample punched out of the lens to fit within the pan of the DSC apparatus. Using DSC, the sample was scanned at a rate of 5 ℃/minute over a temperature range of-40 ℃ to 30 ℃ and the endothermic curve of the sample was recorded. At least two samples from each lens type were tested. Using the endothermic curve determined for each sample, the peaks corresponding to free water and weakly bound water in the endothermic curve were determined and integrated to determine the peak area. The percentage of freezable water present in the sample is calculated using equation (a):

freezable water% wt/wt ═ [ (peak area of free and weakly bound water)/F ] × 100(a),

The F value may be the heating value of pure water melting reported in the literature, or may be the heating value of melting as determined in experiments using the same equipment used to test the samples. For example, based on literature, a value of 340.6J/g may be used for F (the heating value for pure water melting). In the results reported herein, an experimental measurement of 333.4J/g was used for F (calorific value of pure water melting). The percentage of unfrozen water is then calculated using the percentage of freezable water and EWC using equation (B):

For the present contact lenses, contact angles, including dynamic and static contact angles, can be determined using conventional methods known to those skilled in the art. For example, the advancing and receding contact angles of the contact lenses provided herein can be measured using conventional droplet shape methods, such as the sitting drop method or the captive bubble method.

In the following examples 1-4, the advancing and receding contact angles of silicone hydrogel contact lenses were determined using a Kruss (Kruss) DSA 100 instrument (Kruss GmbH, Hamburg) and as described in the following references: d.a. brandreth (d.a. brandreth): "Dynamic contact angle and contact angle hysteresis (Dynamic contact angles and contact angle hysteresis)", Journal of Colloid and Interface Science (Journal of Colloid and Interface Science), Vol.62, 1977, pp.205 to 212; and r. naproski (r.knapikowski), m. kudre (m.kudra): "measurement of contact angle (Kontaktwilkelmessung nach dem Wilhelmy-Prinzip-Ein statischis Ansatz zur Feiherbeuriteung) by error evaluation via William principle statistical method", chemical technique (chem. Technik), Vol.45, 1993, pp.179 to 185; and U.S. patent No. 6,436,481, which are incorporated herein by reference.

As an example, the advancing contact angle and the receding contact angle are measured using a bubble trap method using phosphate buffered saline (PBS; pH 7.2). The lenses were laid flat on a quartz surface and rehydrated with PBS for at least 10 minutes prior to testing. An automatic injection system is used to place air bubbles on the lens surface. The size of the air bubble is increased and decreased to obtain a receding angle (plateau obtained when the bubble size is increased) and an advancing angle (plateau obtained when the bubble size is decreased).

The modulus, elongation and tensile strength values of the lenses of the invention can be determined using conventional methods known to those skilled in the art, for example, according to test methods of ANSI Z80.20. The modulus, elongation and tensile strength values reported herein were determined using an instron 3342 or 3343 mechanical testing system (instron corporation, Norwood (Norwood), MA, usa) and blue hill (Bluehill) materials testing software, where a custom rectangular contact lens cut mold was used to prepare rectangular sample strips. Modulus, elongation and tensile strength are measured in a room having a relative humidity of at least 70%. Lenses intended for testing were soaked in Phosphate Buffered Saline (PBS) for at least 10 minutes prior to testing. The central strip of the lens is cut using a cutting die while the lens is held concave side up. The thickness of the strip was measured using a calibrated gauge (reed electronic thickness gauge, reed Development, inc., Castro Valley, CA, usa). The strips were loaded into the grips of a calibrated instron apparatus using tweezers and the strips fit on at least 75% of the grip surface of each grip. Test methods designed to determine the mean and standard deviation of the maximum load (N), tensile strength (MPa), strain at maximum load (% elongation), and tensile modulus (MPa) were run and the results recorded.

The percent energy loss of the silicone hydrogel contact lenses of the invention can be determined using conventional methods known to those skilled in the art. For the following examples 1-4, the percent energy loss was determined using an instron model 3343 (instron corporation, norwood, ma, usa) mechanical testing system using a 10N force transducer (instron model 2519-. The energy loss is measured in a room with a relative humidity of at least 70%. Prior to testing, each lens was soaked in Phosphate Buffered Saline (PBS) for at least 10 minutes. The lenses are loaded into the clamps of the calibration instron apparatus using tweezers and are loaded vertically between the clamps as symmetrically as possible so that the lenses fit on at least 75% of the clamp surface of each clamp. A test designed to determine the energy required to stretch the lens to 100% strain at a rate of 50 mm/min and then return it to 0% strain was then run on the lens. Only one test is performed on a single lens. After the test is completed, the energy loss is calculated using the following equation: the lost energy (%) — (energy to 100% strain-energy to recover to 0% strain)/energy to 100% strain × 100%.

The ion current of the lenses of the invention can be determined using conventional methods known to those skilled in the art. For the lenses in examples 1-4 below, ion current was measured using a technique substantially similar to the "ion current technique" described in U.S. Pat. No. 5,849,811, which is incorporated herein by reference. The hydrated lens was allowed to equilibrate in deionized water for at least 10 minutes prior to measurement. The lens to be measured is placed in the lens holding device between the convex and concave portions. The male and female portions include a flexible sealing ring between the lens and the respective male or female portion. After placing the lens in the lens holder, the lens holder is then placed in the threaded cap. A cover is screwed onto the glass tube to define the supply chamber. The supply chamber was filled with 16ml of 0.1M NaCl solution. The receiving chamber was filled with 80ml of deionized water. The leads of the conductivity meter were immersed in deionized water in the receiving chamber and a stir bar was added to the receiving chamber. The receiving chamber was placed in a water bath and the temperature was maintained at about 35 ℃. Finally, the supply chamber is immersed in the receiving chamber so that the NaCl solution in the supply chamber is level with the water in the receiving chamber. After the temperature in the receiving chamber had equilibrated to 35 ℃, the conductivity was measured every 2 minutes for at least 10 minutes. The conductivity is substantially linear with time data and is used to calculate the ion flow value of the lens tested.

The oxygen transmission rate (Dk) of the lenses of the invention can be determined using conventional methods known to those skilled in the art. For example, Dk may be a model name of Yuankang (MOCON)Commercially available instruments of the oxygen permeation System (Ox-Tran System) (membrane health (Mocon) corporation, Minneapolis (Minneapolis), MN (MN), usa) are determined, for example, using the membrane health method as described in U.S. patent No. 5,817,924, which is incorporated herein by reference. The Dk values for the lenses in examples 1-4 below were single-lens polarographic measurements of oxygen transmission rate (Dk) of high-throughput soft contact lenses using brakeqi (chubra) et al (2007) (a single-lens polar measurement of oxygen permeability (Dk) for permeable soft contact lenses) biomaterial (Biomaterials) 28: 4331 to 4342, which are incorporated herein by reference.

The percentage of wet extractable or dry extractable components in the lens can be determined by extracting the lens in an organic solvent that does not dissolve the polymeric lens body according to methods known to those skilled in the art. For the lenses in examples 1 to 4 below, the soxhlet extraction method was used for extraction in methanol. For the determination of wet extractable components, samples of fully hydrated and sterilized contact lenses (e.g., at least 5 lenses per batch) were prepared by removing excess packaging solution from each lens and drying it overnight in a vacuum oven at 80 ℃. For determination of dry extractable components, samples of polymeric lens bodies were prepared without washing, extraction, hydration or sterilization by drying the lens bodies overnight in a vacuum oven at 80 ℃. Upon drying and cooling, each lens was weighed to determine its initial dry weight (W1). Each lens was then placed in a porous stackable Teflon (Teflon) sleeve and the sleeves were stacked to form an extraction column with an empty sleeve placed at the top of the column. The extraction column was placed in a small soxhlet extractor attached to a condenser and a round bottom flask containing 70ml to 80ml methanol. Water was circulated through the condenser and methanol was heated until it boiled gently. The lenses were extracted for at least 4 hours from the time of first appearance of condensed methanol. The extracted lenses were dried again overnight in a vacuum oven at 80 ℃. Upon drying and cooling, each lens was weighed to obtain the dry weight of the extracted lens (W2), and the following calculation was performed on each lens to determine the percentage of wet extractable components: [ (W1-W2)/W1] x 100.

Examples 1 to 4

Table 1 lists the ingredients of polymerizable compositions 1 to 4. Polymerizable compositions 1-4 were prepared as described in the hydrogel contact lens manufacturing and testing procedures given above, and the compositions were used to prepare and test hydrogel contact lenses as described in the hydrogel contact lens manufacturing and testing procedures. All lenses prepared in examples 1 to 4 were dry demolded and delensed by hand.

Table 2 shows the lens properties of the lenses formed using polymerizable compositions 1-4 at the time of initial manufacture.

Table 3 shows water content data for lenses prepared from the polymerizable compositions of formulations 1-4 as well as several commercially available silicone hydrogel contact lenses. Commercially available silicone hydrogel contact lenses include comfort oxygen (O2OPTIX)Lenses (Vision, Ciba Vision, deluge, Georgia (GA), usa); anshiyou (ACUVUE)European comfortableness (OASYS)^TMHengrun oxygen (TRUUEYE)(Narafilcon a) and Narafilcon b (narafilcon b)) lenses (Johnson eyesight-improving (Johnson)&Johnson Vision Care) Inc., Jackson Ville (Jacksonville), Florida (FL), USA); and love vitamin A (AVAIRA)Glasses lens and herboringming (BIOFINITY) Lenses (Cooper Vision, Inc., pleisonon, Calif.).

Specifically, table 3 shows EWC (% wt/wt), equilibrium freezable water content (% wt/wt), Standard Deviation (SD) of equilibrium freezable water content (% wt/wt), equilibrium non-freezable water content (% wt/wt), SD of equilibrium freezable water content (% wt/wt), and the ratio of equilibrium freezable water content (% wt/wt) to equilibrium non-freezable water content (% wt/wt). The data reported in table 3 was collected using the methods described in the silicone hydrogel contact lens manufacturing and testing procedures above.

TABLE 1

	Formulations
						1	2	3	4
Si1	30	26	29	36
					Si2	10	10	8
VMA	48	40	42	40
					BVE		7		7
DEGVE			7
					MMA	15	12	14	13
EGMA	7	5		5
					TEGDVE	0.10	0.20	0.08	2.00
EGDMA	0.50		0.60
					TEGDMA		1.30
AE	1.4
					V64	0.50	0.50	0.50	0.50
UV2	0.90	0.90	1.30	0.90
					RBT1	0.01
RBT2		0.01	0.01	0.01
					pTPP		0.50	0.50	0.50
TPP	0.50

TABLE 2

TABLE 3

While the disclosure herein refers to certain illustrated embodiments, it is to be understood that these embodiments are presented by way of example and not limitation. While exemplary embodiments are discussed, the intent of the foregoing detailed description should be construed to cover all modifications, alterations, and equivalents of those embodiments as may fall within the spirit and scope of the invention as defined by the other disclosure.

A number of publications and patents are cited above. Each of the publications and patents cited herein is incorporated by reference in its entirety.

Claims

1. A silicone hydrogel contact lens, comprising:

a polymerized lens body that is the reaction product of a polymerizable composition comprising

(a) At least one siloxane monomer; and

(b) at least one hydrophilic monomer;

wherein the silicone hydrogel contact lens has an equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by differential scanning calorimetry, DSC; and the equilibrium freezable water content is calculated using equation (a):

freezable water% wt/wt ═ [ (peak area of free and weakly bound water)/Y ] × 100 (a),

2. The contact lens of claim 1, wherein the silicone hydrogel contact lens has an equilibrium freezable water content of 27% to 40% (wt/wt) when fully hydrated, as determined by DSC.

3. The contact lens of any preceding claim, wherein the silicone hydrogel contact lens has an equilibrium non-freezable water content of at least 25% wt/wt when fully hydrated, as determined by DSC, and is calculated using equation (B):

Wherein EWC is the equilibrium water content of the lens and the freezable water content of the lens is determined using equation (a).

4. The contact lens of any preceding claim, wherein the silicone hydrogel contact lens, when fully hydrated, has a ratio of equilibrium freezable water content to equilibrium non-freezable water content of at least 3: 1.

5. The contact lens of any preceding claim, wherein the silicone hydrogel contact lens, when fully hydrated, has an equilibrium water content EWC of about 30% wt/wt to about 70% wt/wt as determined by gravimetric analysis; or has a tensile modulus of about 0.2MPa to about 0.9MPa, or has a percent energy loss of about 25% to about 45%, or any combination thereof.

6. The contact lens of any preceding claim, wherein the at least one siloxane monomer comprises a siloxane monomer component comprising a first siloxane and a second siloxane.

7. The contact lens of claim 6, wherein the first siloxane monomer has a number average molecular weight of 400 to 700 daltons.

8. The contact lens of claim 6 or 7, wherein the second siloxane monomer has a number average molecular weight of 7,000 daltons to 20,000 daltons.

9. The contact lens of any preceding claim, wherein the at least one siloxane monomer comprises a monofunctional siloxane monomer represented by formula (3):

wherein m in formula (3) represents an integer of 3 to 10, n in formula (3) represents an integer of 1 to 10, R in formula (3)¹Is an alkyl group having 1 to 4 carbon atoms, and each R in the formula (3)²Independently a hydrogen atom or a methyl group.

10. The contact lens of claim 9, wherein the siloxane monomer represented by formula (3) is a monofunctional siloxane monomer of formula (3), wherein m in formula (3) is 4, n in formula (3) is 1, and R in formula (3) is¹Is butyl, and each R in formula (3)²Independently a hydrogen atom or a methyl group.

11. The contact lens of any preceding claim, wherein the at least one siloxane monomer comprises a difunctional siloxane monomer represented by formula (4):

wherein R in the formula (4)₁Selected from a hydrogen atom or a methyl group; r in the formula (4)₂Selected from a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m in formula (4) represents an integer of 0 to 10; n in formula (4) represents an integer of 4 to 100; a and b represent an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units includes a random configuration.

12. The contact lens of claim 11, wherein the siloxane monomer represented by formula (4) is a bifunctional siloxane monomer represented by formula (4), wherein m in formula (4) is 0, n in formula (4) is an integer of 5 to 15, a is an integer of 65 to 90, b is an integer of 1 to 10, R in formula (4)₁Is methyl, and R in formula (4)₂Is a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms.

13. The contact lens of any preceding claim, wherein the at least one hydrophilic monomer is present in the polymerizable composition in an amount from 30 to 60 unit parts by weight.

14. The contact lens of claim 13, wherein the at least one hydrophilic monomer comprises a hydrophilic amide monomer having one N-vinyl group.

15. The contact lens of any preceding claim, wherein the polymerizable composition further comprises at least one vinyl-containing crosslinking agent.

16. A batch of silicone hydrogel contact lenses,

wherein the batch comprises a plurality of silicone hydrogel contact lenses formed from polymerized lens bodies that are the reaction product of a polymerizable composition comprising

(a) At least one siloxane monomer; and

(b) at least one hydrophilic monomer;

wherein the batch of silicone hydrogel contact lenses has an average equilibrium freezable water content of at least 25% wt/wt when fully hydrated, as determined by differential scanning calorimetry, DSC; and the equilibrium freezable water content is calculated using equation (a):

17. The batch of silicone hydrogel contact lenses of claim 16, wherein the silicone hydrogel contact lenses, when fully hydrated, have at least one property selected from the group consisting of: an average equilibrium water content, EWC, of from about 30% wt/wt to about 70% wt/wt, or an average tensile modulus of from about 0.2MPa to about 0.9MPa, or an average percent energy loss of from about 25% to about 45%, or an average Dk of at least 55 barrers, or less than about 8 x 10^-3mm²An average ion current per min, or an average captive bubble dynamic advancing contact angle of less than 120 degrees, or an average captive bubble static contact angle of less than 55 degrees, or an average wet extractable component content of less than 10% wt/wt, or an average dry extractable component content of less than 20% wt/wt, or any combination thereof.

18. A method of manufacturing a silicone hydrogel contact lens, comprising:

providing a polymerizable composition comprising

(a) At least one siloxane monomer, and

(b) at least one hydrophilic monomer;

polymerizing the polymerizable composition in a contact lens mold assembly to form a polymeric lens body;

contacting the polymeric contact lens body with a washing liquid to remove extractable material from the polymeric contact lens body; and

packaging the polymeric contact lens body in a contact lens packaging solution in a contact lens package;

19. The method of claim 18, wherein the polymerizing step comprises polymerizing the polymerizable composition in a contact lens mold assembly having a molding surface formed from a non-polar thermoplastic polymer to form the polymeric lens body.

20. The method of claim 18 or 19, wherein the contacting step comprises contacting the polymeric contact lens body with a washing solution that is free of volatile organic solvents.