HK1205792B - Contact lenses made with hema-compatible polysiloxane macromers - Google Patents

Description

Contact lenses made with HEMA-compatible polysiloxane macromers

The present application claims the benefit of the previous U.S. provisional patent application No. 61/694,011, filed on 8/28/2012 and 61/786,761, filed on 3/15/2013, as filed on 8/28/2012, by 35u.s.c. § 119(e), which is incorporated herein by reference in its entirety.

Background

The field of the present disclosure is contact lenses formed from the copolymerization of hydroxyalkyl methacrylates with HEMA-compatible bifunctional polysiloxanes.

2-hydroxyethyl methacrylate (HEMA) is a biocompatible polymerizable monomer that has been used in the manufacture of soft hydrogel contact lenses for over 40 years. HEMA-based hydrogel contact lenses are much more comfortable to wear than previous hard contact lenses. One disadvantage of HEMA-based hydrogel lenses, however, is that they have low oxygen permeability. Materials that provide higher oxygen permeability are known to be more beneficial to the health of the cornea of the eye. At the end of the 1990's, silicone hydrogel contact lenses were introduced on the market, which have significantly higher oxygen permeability than HEMA-based hydrogel lenses. However, the siloxane monomers used to make silicone hydrogels are typically much more expensive than HEMA. In addition, the methods for manufacturing silicone hydrogel contact lenses are substantially more complex and labor intensive than methods for manufacturing HEMA-based hydrogel contact lenses. It is therefore desirable to combine the benefits of HEMA with the oxygen permeability properties of silicone hydrogels, however HEMA is extremely hydrophilic and generally immiscible with silicone monomers.

Background publications include U.S. patent No. 8,053,544, U.S. patent No. 8,129,442, U.S. patent No. 4,260,725, U.S. patent publication No. 2011/0181833, U.S. patent publication No. 20060063852, and U.S. patent publication No. 2011/0140292.

Disclosure of Invention

We have discovered HEMA-compatible siloxane monomers useful in the manufacture of contact lenses that combine the attributes of HEMA-based contact lenses with the high oxygen permeability of silicone hydrogel lenses.

Disclosed herein is an optically clear silicone hydrogel contact lens comprising a polymeric lens body that is the reaction product of a polymerizable composition comprising at least 25 wt-% of at least one hydroxyalkyl methacrylate and at least 20 wt-% of at least one HEMA-compatible bifunctional polysiloxane. The polysiloxane is difunctional, i.e. it contains 2 polymerizable acrylate or meth (acrylate) groups. The polysiloxane additionally comprises at least 6 siloxane groups and i) has an HLB value of at least 5, or ii) has a hydroxyl content of at least 1 wt.%, or iii) has both an HLB value of at least 5 and a hydroxyl content of at least 1 wt.%. The contact lens may have any of the other features described as examples in the following paragraphs, or any combination of non-mutually exclusive other features.

In one example, the HEMA-compatible bifunctional polysiloxane has a molecular weight of 1K to 20K.

In another example, the HEMA-compatible bifunctional polysiloxane has an elemental silicon content of at least 10 weight percent, optionally in combination with the above molecular weight characteristics.

In one particular example, the HEMA-compatible bifunctional polysiloxane, optionally in combination with one or both of the other features described above, has the structure of formula 1:

wherein R is₁And R₂Independently selected from hydrogen or methyl, k is an integer of 0 or 1, m is an integer of at least 6, n is an integer of at least 1, p is an integer of at least 1 and R is₁Is hydrogen or methyl. In another example, m is an integer from 6 to 100, n is an integer from 1 to 75, and p is an integer from 1 to 40. In yet another example, m is an integer from 6 to 60, n is an integer from 1 to 10, and p is an integer from 10 to 30. In yet another example, m is an integer from 30 to 60, n is an integer from 30 to 60, p is an integer from 1 to 6, and R is₁Is hydrogen.

In one example, the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 7. In another example, the HEMA-compatible bifunctional polysiloxane has an HLB value of less than 5 and a hydroxyl content of at least 1 wt.%. In yet another example, the HEMA-compatible bifunctional polysiloxane has an HLB value of 2 to 4 and a hydroxyl content of 4 to 8 weight percent.

The polymerizable composition used to make a contact lens of any of the above examples or combinations of examples can additionally comprise 1 to 65 wt% of a diluent, wherein the diluent comprises water, low molecular weight polyethylene glycol, PEG, or a combination thereof. In a particular example, the HEMA-compatible bifunctional polysiloxane requires the addition of water for optical clarity.

In any of the preceding examples or example combinations, the polymerizable composition can further comprise 0.1 to 5 weight percent methacrylic acid.

In any of the preceding examples or example combinations, the polymerizable composition can comprise at least 35 wt.% of the hydroxyalkyl methacrylate.

In any of the preceding examples or example combinations, the hydroxyalkyl methacrylate can be 2-hydroxyethyl methacrylate (HEMA).

In any preceding example or combination of examples, the contact lens can have a Dk of at least 35. In another example, the HEMA-compatible bifunctional polysiloxane provides the contact lens with an oxygen permeability increase of at least 50%.

Also disclosed herein is a method of manufacturing an optically clear contact lens according to any one of the foregoing examples or combinations of examples. The method comprises polymerizing a polymerizable composition to form a polymeric lens body and hydrating the polymeric lens body, wherein the polymerizable composition comprises at least 25 wt-% of at least one hydroxyalkyl methacrylate and at least 20 wt-% of at least one HEMA-compatible bifunctional polysiloxane, and wherein the polymerizable composition is free of diluent or comprises about 1 to 65 wt-% of a diluent consisting essentially of water or low molecular weight PEG, or a combination thereof. In one particular example of the method, the polymeric lens body is not contacted with a volatile organic solvent during the hydrating step. In another example, the polymerizing step comprises heat curing in air.

Also disclosed herein is a composition comprising a polysiloxane of formula 3:

wherein R is₂Selected from hydrogen or methyl, m is an integer from 6 to 50, n is an integer from 1 to 6 and p is an integer from 8 to 20, and wherein the composition comprises at least 75% polysiloxane and at least 20% by weight is miscible in HEMA. In a particular example, the composition comprises a polysiloxane of formula 3, wherein R₂Is methyl, m is an integer from 6 to 25, n is an integer from 1 to 4 and p is an integer from 12 to 18.

Detailed Description

Through extensive research, a HEMA-compatible polysiloxane macromer has been developed that can be used to make optically clear silicone hydrogel contact lenses having high HEMA content. Thus, the polysiloxane macromers disclosed herein can be used to manufacture contact lenses with HEMA or other hydroxyalkyl (meth) acrylates, thereby combining the benefits of HEMA with the oxygen permeability properties of silicone hydrogels. The polysiloxane is difunctional, as used herein, meaning that it contains two polymerizable acrylate or meth (acrylate) groups. It further comprises at least 6 Siloxane (SiO) groups and has an HLB value of at least 5 and/or a hydroxyl content of at least 1 wt.%.

HEMA compatibility means that the bifunctional polysiloxane formed optically clear lenses made from the following test formulations and processes. The test formulation consists essentially of a mixture of 20 parts of the difunctional polysiloxane, 80 parts HEMA, 0.5 parts Ethylene Glycol Dimethacrylate (EGDMA), 0.5 parts polymerization initiator 2,2' -azobis (2, 4-dimethylvaleronitrile) V52, optionally 0.1 to 2 parts Methacrylic Acid (MA), and optionally 0.1 to 30 parts water, wherein parts are by weight based on the total weight of the test formulation, which is the polymerizable composition. The test formulations were cured in polypropylene contact lens molds for 1 hour at 80 ℃. Upon curing, the mold is opened and the resulting polymeric lens body is mechanically removed from the mold (i.e., dry delensing) or wet delensing by immersing the mold in water until the polymeric lens body is hydrated and floats off the mold. After delensing, the polymer lens bodies were placed in room temperature clear water for 20 minutes, then placed in contact lens blisters containing 1.8ml Phosphate Buffered Saline (PBS), sealed, and sterilized by autoclaving. If the resulting lenses were optically clear after autoclave sterilization, it was confirmed that at least 20 wt% of the polysiloxane was miscible in HEMA and thus considered HEMA compatible. If the lens shows a light transmission of at least 90% between 381nm and 780nm (measured according to ISO 18369), it is considered optically transparent. If a transparent lens is formed using the above-described method for a difunctional polysiloxane formulation (except that the formulation has 30 parts polysiloxane and 70 parts HEMA), at least 30 weight percent of the polysiloxane is said to be miscible in HEMA. In various examples, the difunctional polysiloxanes described herein are at least 25, 30, 35, 40, 45, or 50 weight percent miscible in HEMA. Throughout this disclosure, reference to "an example," "one example," or "one particular example," or similar phrases, is intended to refer to one or more features of the contact lens, unless a particular combination of features is mutually exclusive or otherwise indicated herein, the HEMA-compatible polysiloxane, polymerizable composition, or method of manufacture (as hereinafter described) can be combined with any combination of the previously described or subsequently described examples (i.e., features).

Some of the HEMA-compatible polysiloxanes described herein are miscible in the above-described test formulations without the addition of any water (i.e., the mixture is clear), but upon curing and hydration form cloudy lenses. We found that: by adding water to the polymerizable composition, the resulting lens will be optically clear. In such examples, the HEMA-compatible polysiloxane is said to require the addition of water to provide HEMA compatibility, however, it is understood that diluents other than water may also form optically clear lenses. Thus, in various examples, the polymerizable composition further comprises from about 1, 5, or 10 wt.% to about 30, 50, or 65 wt.% of a diluent, wherein the wt.% of the diluent is based on the total weight of the polymerizable composition. As used herein, the term diluent refers to the non-polymerizable component of the polymerizable composition that is added to render the polysiloxane compatible (i.e., miscible) with HEMA (or other hydroxyalkyl methacrylates). In some examples, the diluent consists essentially of water, low molecular weight polyethylene glycol (PEG), or a combination thereof. As used herein, low molecular weight PEG has an average molecular weight of less than about 1500, and in some examples, less than about 1200, 1000, or 800. In some examples, HEMA-compatible polysiloxanes can be prepared by a hydrosilation reaction in which side chains derived from low molecular weight reactive PEG (e.g., hydroxypolyethylene glycol allyl ether) are bonded to the polysiloxane, as described in example 2 below. In such examples, the hydrosilation reaction product may comprise at least 70, 75, or 80 weight percent of the HEMA-compatible polysiloxane, with the remaining components being PEG and reactive PEG (e.g., OH-PEG allyl ether). In such examples, the PEG and OH-PEG allyl ether can be removed by further purifying the HEMA-compatible polysiloxane to provide a HEMA-compatible polysiloxane having a purity of at least 85, 90, or 95 weight percent. An exemplary purification method is described below and in example 6. Alternatively, the PEG and reactive PEG can be retained as a low molecular weight PEG diluent in the polymerizable composition. Thus, the term "low molecular weight PEG diluent" encompasses reactive PEG (e.g., OH-PEG allyl ether) having an average molecular weight ≦ 1500 used in the preparation of the polysiloxane. In particular examples, the diluent is substantially free of components containing non-polymerizable polysiloxanes, such as polysiloxane surfactants, silicone oils, or other diluents known for use in silicone hydrogel contact lens formulations. One advantage of the water and low molecular weight PEG diluent described herein is that the contact lenses can be manufactured without the use of volatile solvents.

The hydrophilicity of a silicone macromer is represented by its hydrophilic-lipophilic balance (HLB) value, which is calculated as twenty times the molecular weight of the hydrophilic portion of the polysiloxane divided by the total molecular weight of the polysiloxane. For example, a HEMA-compatible polysiloxane can have the structure shown in formula 1, wherein R₁Is hydrogen. In such examples, polyethylene oxide groups (PEO; -CH)₂CH₂O-) and terminal hydroxyl (-OH) groups constitute the hydrophilic part of the polysiloxane. One example of such a polysiloxane is described in example 2 below (designated as H10P16) and is represented by the following formula 1 (where k is 0, m is 19.7, n is 2.5, P is 16, R₁Is hydrogen and R₂Is methyl).

Thus, based on these values, the HLB value of H10P16 was calculated to be about 10.9. In the case of polydisperse molecules (e.g., polysiloxanes as described herein), the term "molecular weight" refers to the absolute number average molecular weight (in daltons) of the monomer, such as by¹HNMR end group analysis (NM)R) is determined. Similarly, the m, n and p values are the average values determined by NMR. Thus, in various examples, the polysiloxane has an HLB value of at least 6,7, or 8 and at most about 10, 11, or 12. It is to be understood that the polysiloxane may comprise hydrophilic groups that contribute to HLB values in place of or in addition to PEO and/or hydroxyl groups. Examples of such other groups include carbamate groups, amide groups, and diol groups.

Throughout this disclosure, when a range of lower limits and a range of upper limits are provided, all combinations of the provided ranges are encompassed, as if each combination were specifically listed. For example, in the above list of HLB values, all 9 possible HLB ranges are encompassed (i.e., 6-10, 6-11 … 8-11, and 8-12). Additionally, throughout this disclosure, when a series of values is presented with a qualifier preceding the first value, the qualifier is intended to explicitly precede each value in the series unless the context indicates otherwise. For example, in terms of the above HLB values, it is desired that the qualifier "at least" explicitly precede 7 and 8 and the qualifier "to about" explicitly precede 11 and 12.

When the HEMA compatibility of the polysiloxane is determined in the manner described above using the test formulation, the polymerizable composition used to manufacture the contact lenses described herein may comprise monomers other than hydroxyalkyl methacrylates, provided that the composition comprises at least 25 wt.% of at least one hydroxyalkyl methacrylate and at least 20 wt.% of at least one HEMA-compatible bifunctional polysiloxane comprising at least 6 siloxane groups and having an HLB value of at least 5 and/or comprising a hydroxyl content of at least 1 wt.%. As used herein, the weight% of monomers (i.e., hydroxyalkyl methacrylate, HEMA-compatible polysiloxane, and any other polymerizable components of the polymerizable composition) is based on the total weight of polymerizable monomers in the composition, i.e., does not include diluent and any other non-polymerizable components.

The hydroxyalkyl methacrylate can be any lower hydroxyalkyl methacrylate suitable for use in contact lenses. In a particular example, the hydroxyalkyl methacrylate is selected from HEMA, 2-hydroxybutyl methacrylate (HOB), 2-hydroxypropyl methacrylate (HOP), and combinations thereof. For example, in the case of a composition comprising 10 wt.% HOB and 15 wt.% HOP, the composition is said to comprise 25 wt.% of at least one hydroxyalkyl methacrylate. In other words, the composition may comprise a combination of hydroxyalkyl methacrylates, provided that the sum thereof is at least 25 wt%. Similarly, the composition may comprise a combination of two or more HEMA-compatible bifunctional polysiloxanes having an HLB value of at least 5 and/or comprising at least 1 wt.% hydroxyl content, provided that the sum thereof in the composition is at least 20 wt.%. Thus, unless the context indicates otherwise, reference to "a", "an", or "the" particular type of monomer (e.g., "the HEMA-compatible polysiloxane" or "a hydroxyalkyl methacrylate") is meant to encompass "one or more" of that type of monomer. In various examples, the polymerizable composition comprises at least 30, 35, or 40 weight percent of the hydroxyalkyl methacrylate and at least 25, 30, or 35 weight percent of the HEMA-compatible polysiloxane. In addition to the hydroxyalkyl methacrylate and the HEMA-compatible polysiloxane, the polymerizable composition can include other monomers. Exemplary other monomers include N-vinyl-N-methylacetamide (VMA), N-vinyl pyrrolidone (NVP), 1, 4-Butanediol Vinyl Ether (BVE), Ethylene Glycol Vinyl Ether (EGVE), diethylene glycol vinyl ether (DEGVE), N-Dimethylacrylamide (DMA), Methyl Methacrylate (MMA), ethoxyethyl methacrylamide (EOEMA), ethylene glycol methyl ether methacrylate (EGMA), isobornyl methacrylate (IBM), Glycerol Methacrylate (GMA), Methacrylic Acid (MA), Acrylic Acid (AA), or any combination of two or more of the foregoing other monomers. In a particular example, the polymerizable composition comprises from about 0.1, 0.5, 1 wt% up to about 2, 3, or 5 wt% MA or AA.

The polymerizable composition can also include polymerizable siloxanes, as described above, that are not necessarily HEMA compatible, present in an amount wherein the other polymerizable siloxanes remain miscible such that the resulting lens is optically clear. Examples of other polymerizable siloxanes include 3- [ TRIS (trimethylsiloxy) silyl ] propyl methacrylate ("TRIS"), 3-methacryloxy-2-hydroxypropoxy) propylbis (trimethylsiloxy) methylsilane ("SiGMA"), methyl bis (trimethylsiloxy) silylpropylglycerol ethyl methacrylate ("SiGEMA"), and monomethacryloxypropyl functional polydimethylsiloxanes (e.g., MCR-M07 and MCS-M11), all available from Gelest (Morrisville, Pa., USA). Other polymerizable siloxanes are known in the art (see, e.g., U.S. patent No. 7,572,841, U.S. patent No. 5,998,498, U.S. patent No. 5,965,631, U.S. patent publication No. 2006/0063852, U.S. patent publication No. 2007/0296914, U.S. patent No. 2009/0299022, U.S. patent No. 6,310,169, and U.S. patent No. 6,867,245, each of which is incorporated herein by reference).

While the HEMA-compatible silicone is difunctional and thus acts as a crosslinker in the polymerizable composition, the polymerizable composition may also include other crosslinkers to obtain a hydrogel having physical properties suitable for use in a contact lens. Various crosslinking agents are known in the art. Exemplary crosslinkers are triethylene glycol dimethacrylate (TEGDMA) and Ethylene Glycol Dimethacrylate (EGDMA).

Typically, the polymerizable composition will additionally comprise a colorant (e.g., a stain (e.g., VatBuse 6) or a polymerizable dye (e.g., RB 19-HEMA; see, e.g., WO 201302839)). In a particular example, the polymerizable composition consists of: (a) said HEMA-compatible polysiloxane; (b) hydroxyalkyl methacrylate; (c) a monomer selected from methacrylic acid or acrylic acid or glycerol methacrylate or a combination thereof; and optionally (d) a cross-linking agent and/or a polymerizable dye; and no other polymerizable components.

The HEMA-compatible polysiloxane described herein is not subject to particular size constraints, but will generally have a molecular weight of at least 1K, 2K, or 3K to about 10K, 20K, or 30K. In some examples, the polysiloxane has a silicone content selected to provide a silicone coating on the surface of the HEMA-compatible polysiloxaneThe oxygen permeability (Dk) of the contact lens is selected to increase by at least 25%, 50%, 75% or 100% over a comparable HEMA lens, wherein the oxygen permeability of the contact lens is measured using standard methods in the industry (in barrer), for example by Chhabra et al, (2007), single lens polarographic measurements of oxygen permeability for ultra-high transmission soft contact lenses (ash-lentiolographical measurements of oxygen permeability (Dk) for hyper-transmissive soft contact lenses) biomaterial (Biomaterials)28: 4331-. For example, if a contact lens made with a HEMA-compatible bifunctional polysiloxane (as described herein) has a Dk of 30 and an equivalent HEMA contact lens has a Dk of 15, the HEMA-compatible polysiloxane is said to provide the contact lens with a 100% increase in oxygen permeability, as determined by the following equation: increment [ [ (Dk)_H–Dk_C)/Dk_C]× 100, wherein Dk_HAnd Dk_CAs used herein, a "comparable HEMA contact lens" is made from a polymerizable composition in which HEMA and optionally methacrylic acid are substituted for the HEMA-compatible difunctional polysiloxane, but are otherwise substantially the same, if desired, an amount of methacrylic acid is added to the comparative formulation such that the resulting comparative lens has a similar Equilibrium Water Content (EWC) as the lens containing the HEMA-compatible polysiloxane, for measuring the EWC, the excess surface moisture of the lens is wiped off and the lens is weighed to obtain a water-containing weight, the lens is dried in an oven and weighed under 80 ℃ and vacuum, the weight difference is measured by subtracting the dry lens weight from the water-containing lens weight, the EWC% (weight difference/water-containing weight) × 100 of the lens, in various examples, the HEMA polysiloxane has an average molecular weight of at least 8, 10, 12, 14, 16, 18, or 20 wt% relative to the HEMA polysiloxane, and the contact lens has an average silicon content of at least about 30 wt%, or more than the other examples, and the HEMA-compatible polysiloxane has an EWC content of at least about 40 wt%.

As described above, exemplary HEMA phasesThe compatible difunctional polysiloxane comprises polyethylene oxide groups (PEO), typically as side chains to one or more of the siloxane groups (e.g., p groups as in formula 1 for example) and/or as groups adjacent to functional (i.e., polymerizable) end groups of the polysiloxane (e.g., k groups as in formula 1 for example). Methods of making polysiloxanes comprising PEO groups are described in U.S. patent No. 8,053,544, U.S. patent No. 8,129,442, and U.S. patent publication No. 2011/0140292. In one particular example, the HEMA-compatible polysiloxane has the structure of formula 1 above, where k is an integer of 0 or 1, m is an integer of at least 6, n is an integer of at least 1, p is an integer of at least 1, and R is₁And R₂Independently selected from hydrogen or methyl. In various such examples, m is an integer of at least 10, 15, 20, or 30 to about 50, 60, 80, or 100; n is an integer of at least 1, 2 or 4 to about 6,8, 10 or 12. In another example, m is an integer within the foregoing range and n is an integer of at least 10, 15, or 30 to about 40, 60, or 80. In various examples, k, m, and p are any of the foregoing values and R₁Is hydrogen. In such examples, the polysiloxane can have a hydroxyl content of at least 1 wt.%. In some examples, the HEMA-compatible polysiloxane has an average hydroxyl content of about 1, 2, or 3 wt.% to about 5,7, 10, or 15 wt.%, wherein the wt.% of-OH groups are based on the average molecular weight of the polysiloxane. We have found that polysiloxanes having a relatively high hydroxyl content, while having a relatively low HLB value, can be HEMA compatible. Thus, in various examples, the polysiloxane has an HLB value of 1, 2, 3 to 5,6, 7, or 8 and has a hydroxyl content of about 1, 2, or 3 wt.% to about 5,7, or 10 wt.%. In a particular example, the polysiloxane has an HLB value of 3 to 5 and a hydroxyl content of about 4 to 8 wt%. For example, polysiloxanes of formula 1 (wherein k is 0, R)₁Is hydrogen, R₂Is methyl, m is 71, n is 50 and p is 1) has a hydroxyl content of about 6% and an HLB value of about 4 and is HEMA compatible as described above without the addition of water. In various other examples, the polysiloxane has the structure of formula 1, wherein k is 0 and R₁Is hydrogen, R₂Is hydrogen or methyl, m is an integer from 6 to 100, n is an integer from 1 to 75And p is an integer from 1 to 40. In another example, the polysiloxane has the structure of formula 1, wherein k is 0 and R₁Is hydrogen, R₂Is hydrogen or methyl, m is an integer from 6 to 60, n is an integer from 1 to 10 and p is an integer from 10 to 30.

Methods for making HEMA-compatible polysiloxanes and contact lenses comprising the same are described in the examples below. In one particular method, the intermediate polysiloxane of formula 2 (wherein R is₂Hydrogen or methyl):

octamethylcyclotetrasiloxane, 1,3,5, 7-tetramethylcyclotetrasiloxane and 1, 3-bis (3-methacryloxypropyl) -1,1,3, 3-tetramethyldisiloxane were reacted with trifluoromethanesulfonic acid and the reaction was neutralized with magnesium oxide. Next, a hydrosilylation reaction is used to bond the PEO-containing side chains to the intermediate polysiloxane of formula 2 to form a HEMA-compatible polysiloxane of formula (3):

wherein R is₂Is hydrogen or methyl, and m, n and p have any one or a combination of values indicated in the preceding paragraphs. In one particular example, the HEMA-compatible polysiloxane has a structure represented by formula (3) (wherein R is₂Is methyl, m is an integer from 6 to 50, n is an integer from 1 to 6 and p is an integer from 8 to 20) and at least 30 weight percent is miscible in HEMA. In another example, the polysiloxane has a structure represented by formula (3), wherein R₂Is methyl, m is an integer from 6 to 25, n is an integer from 1 to 4 and p is an integer from 12 to 18.

In various other examples, the HEMA-compatible bifunctional polysiloxane has the structure of formula 4:

wherein R is₁And R₂Independently selected from hydrogen or methyl, k is an integer of 0 or 1, m is an integer of 0 to 160, n is an integer of 1 to 75, p is an integer of 0 to 40 and q is an integer of 0 to 20. In one particular example, m is an integer from 6 to 100, n is an integer from 1 to 75, p is an integer from 1 to 40, and q is 0. In another particular example, m is an integer from 6 to 60, n is an integer from 1 to 10, p is an integer from 10 to 30, and q is 0.

In some examples, the HEMA-compatible bifunctional polysiloxane has the structure of formula 4, wherein m is 0, i.e., the polysiloxane does not contain any Polydimethylsiloxane (PDMS). In various of the examples, the polysiloxane has the structure of formula 4, where m is 0, n is an integer from 10 to 60, p is an integer from 0 to 6, q is 0, and R is₁Is hydrogen. In another example, the polysiloxane has a structure of formula 4, where m is 0, n is an integer from 20 to 40, and p is 0. Examples 8-10 below describe methods for synthesizing PDMS-free HEMA-compatible bifunctional polysiloxanes.

In other examples, the HEMA-compatible bifunctional polysiloxane comprises side chains comprising ethylene oxide and propylene oxide units. In one such example, the HEMA-compatible bifunctional polysiloxane has the structure of formula 4, wherein m is an integer from 6 to 60, n is an integer from 1 to 10, p is an integer from 1 to 40, and q is an integer from 1 to 10. In another example, the HEMA-compatible bifunctional polysiloxane has a structure of formula 4, wherein m is an integer from 6 to 50, n is an integer from 1 to 6, p is an integer from 8 to 20, and q is an integer from 2 to 8. The synthesis of one such exemplary polysiloxane is described in example 7.

Provided herein is a method of purifying the HEMA-compatible bifunctional polysiloxane to remove unreacted PEG-containing reagents (e.g., OH-PEG allyl ether, PEG-polypropylene glycol allyl ether, etc.). In one exemplary method, the hydrosilylation reaction product (e.g., the HEMA-compatible polysiloxane, unreacted polyethylene glycol-containing reagent, and any other unreacted reagents) is combined with an organic solvent and water, or with an organic solvent and an aqueous solution, to produce a mixture. Suitable organic solvents include ethyl acetate, dichloromethane, and the like. Suitable aqueous solutions include saline solutions, sodium citrate, and the like. Agitation (e.g., rotary shaking or vigorous stirring) may be used to facilitate mixing of the organic and aqueous phases. Next, the mixture was equilibrated to separate into an organic layer and an aqueous layer containing unreacted PEG-containing reagent. Centrifugation may be used in the equilibration step to facilitate phase separation. Subsequently, the aqueous layer was discarded from the organic layer. The polysiloxane can be isolated from the organic layer using standard techniques (e.g., removal of residual aqueous solution using a dehydrating agent (e.g., anhydrous sodium sulfate), and removal of organic solvent using air/gas flow, reduced pressure, elevated temperature, and/or combinations of these) and other techniques. Optionally, the organic layer and water or aqueous solution can be combined again and the equilibration step and discard step repeated one or more times until the desired purity is achieved. In various examples, the HEMA-compatible bifunctional polysiloxane is purified to at least 85, 90, 95, 98, or 99 weight percent.

Optically clear contact lenses can be made from the HEMA-compatible bifunctional polysiloxanes described herein using curing and other processing methods known in the art. One exemplary method comprises preparing a polymerizable composition comprising at least 25 wt.% of at least one hydroxyalkyl methacrylate, at least 20 wt.% of a HEMA-compatible bifunctional polysiloxane, a polymerization initiator, and optionally 1 to 65 wt.% of a diluent. The polymerizable composition is filled into a contact lens mold, which is typically made from a thermoplastic polymer (e.g., polypropylene). Typically, a first mold member (referred to as a "female mold member") defining the anterior surface of the contact lens is filled with the polymerizable composition in an amount sufficient to form a single polymeric lens body. A second mold member (referred to as the "male mold member") defining the back surface of the contact lens (i.e., in contact with the eye) is coupled to the female mold member to form a mold assembly having a lens-shaped cavity with an amount of polymerizable composition therebetween. Subsequently, the polymerizable composition within the contact lens mold assembly is polymerized using any suitable curing method. Typically, the polymerizable composition is exposed to a large amount of heat or ultraviolet light (UV) to polymerize. In the case of UV curing, also referred to as photopolymerization, the polymerizable composition typically comprises a photoinitiator, for example benzoin methyl ether, 1-hydroxycyclohexyl phenyl ketone, Darocur or Irgacur (available from ciba specialty chemicals). Photopolymerization methods for contact lenses are described in U.S. patent No. 5,760,100. In the case of thermal curing (also referred to as thermal curing), the polymerizable composition typically comprises a thermal initiator. Exemplary thermal initiators include 2,2' -azobis (2, 4-dimethylvaleronitrile) (V-52), 2' -azobis (2-methylpropionitrile) (V-64), and 1,1' -azobis (cyanocyclohexane) (V-88). In some examples, the polymerizable composition is thermally cured in a nitrogen oven. In one particular example, the polymerizable composition comprises V-52 and is cured in air at about 80 ℃ for about 1 hour.

Upon completion of curing, the polymeric material located between the mold members of the mold assembly has the shape of a contact lens and is referred to herein as a "polymeric lens body". The male mold part is demolded (i.e., separated) from the female mold part and the polymeric lens body adhered thereto is removed (i.e., delensed) from the mold part. These methods are referred to as demolding and delensing, respectively, and each such method is known to those skilled in the art. In some methods, the demolding and delensing methods may include a single processing step, such as using a liquid separation mold that also removes the polymeric lens body from the mold. In other processes (e.g., when a dry demolding process is used), the polymeric lens body is typically left on one of the mold members and delensed in a subsequent process step. Delensing can also be a wet or dry process. In one example, delensing is performed by a "float-off" process in which a mold part to which the polymeric lens body is adhered is immersed in water. The water may optionally be heated (e.g., up to about 100 ℃). Typically, the polymeric lens body drifts away from the mold part in about ten minutes. In one particular example, the polymeric lens body is dry delensed from the mold followed by hydration of the polymeric lens body. Dry delensing can be performed manually, such as using tweezers to remove the polymeric lens body from the mold member, or it can be removed using automated mechanical methods, such as those described in U.S. patent No. 7,811,483. Other demolding and delensing methods for silicone hydrogel contact lenses are described in U.S. patent publication No. 2007/0035049.

After delensing, rinsing the polymeric lens body to remove unreacted or partially reacted ingredients from the polymeric lens body and to hydrate the polymeric lens body. In one particular example, the polymer lens body is rinsed in a rinse solution that is free of volatile organic solvents (e.g., methanol, ethanol, chloroform, etc.), and all liquids used to rinse the polymer lens body are free of volatile organic solvents. Such washing may also be referred to herein as "organic solvent free extraction," where "organic solvent" refers to volatile organic solvents. For example, a washing step using an aqueous solution of a surfactant (e.g., Tween (Tween)80) without any volatile organic solvent is considered to be a volatile organic solvent-free extraction. In another example, the polymer lens body does not contact any volatile organic solvent during the manufacturing process (i.e., from the time the curing of the polymer lens body is complete to the time it is sealed in its final package). Although the polymerizable compositions described herein can be used to make polymeric lens bodies that can be rinsed without the use of volatile organic solvents, they can also be rinsed with organic solvents, if desired. Thus, the rinsing step can include contacting the polymeric lens body with a volatile organic solvent, such as a lower alcohol (e.g., methanol, ethanol, etc.), contacting the polymeric lens body with an aqueous liquid that may or may not contain a volatile organic solvent, a solute, or a combination thereof. Exemplary rinsing methods are described in U.S. patent publication No. 2007/0296914 and example 3 below.

After rinsing and any optional surface modification, the hydrated polymer lens body is typically placed in a blister pack, glass bottle, or other suitable container, all referred to herein as a "package," which contains a packaging solution (typically a buffered saline solution, such as phosphate-or borate-buffered saline). The packaging solution may optionally include other ingredients such as comfort agents, hydrophilic polymers, surfactants or other additives that prevent the lens from sticking to the container, and the like. The package is sealed and the sealed polymeric lens body is sterilized by applying a sterilizing amount of radiation (including heat or steam) (e.g., by autoclaving, gamma radiation, electron beam radiation, ultraviolet radiation, etc.). The finished product is a sterile packaged type optical transparent silicone hydrogel contact lens.

The following examples illustrate some aspects and advantages of the present invention, it being understood that the invention is not so limited.

Example 1: process for preparing polysiloxane intermediates

202.20g of octamethylcyclotetrasiloxane (LS8620, Shin-Etsu chemical), 21.87g of 1,3,5, 7-tetramethylcyclotetrasiloxane (LS8600, Shin-Etsu chemical Co., Ltd.), and 56.63g of 1, 3-bis (3-methacryloxypropyl) -1,1,3, 3-tetramethyldisiloxane (X-22-164, Shin-Etsu chemical Co., Ltd.) were added to a500 ml Kjeldahl flask. 0.62g of trifluoromethanesulfonic acid (WakoPure chemical industries, Ltd.) was added to this solution and stirred at 35 ℃ for 3 hours. Thereafter, 0.7025g of magnesium oxide (light) (Wako pure chemical industries, Ltd.) and 100ml of hexane (anhydrous) were added and stirred at room temperature for 1 hour. The reaction mixture was suction-filtered through No. 545 diatomaceous earth (Wako pure chemical industries, Ltd.) and No. 5A KIRIYAMA filter paper. The filtrate was evaporated and dried in vacuo at 35 ℃. Then, the reaction mixture was gradually heated to 165 ℃ over 30 minutes at 1-2 mmHg with stirring, and low molecular impurities were removed from the organic phase under reduced pressure (about 1mmHg) and 165 ℃ over 2 h. The reaction yielded 253.27g of the intermediate siloxane of formula 2 (above).

Example 2: preparation of HEMA-compatible polysiloxane macromonomers

60.01g of intermediate siloxane of formula 2, 83.43g of hydroxypolyethyleneglycol allyl ether having an average molecular weight of about 750 (UnioxPKA5004, NOFCcorporation), 120.00g of 2-propanol (super-dehydrated grade) (Wako pure chemical industries, Ltd.), 0.60g of an ethanol solution of 10% potassium acetate (Wako pure chemical industries, Ltd.), 1.36g of a 2-propanol solution of 1% of 2, 6-di-tert-butyl-4-methylphenol (Wako pure chemical industries, Ltd.), and 0.69g of a 2-propanol solution of 1% of p-methoxyphenol (Wako pure chemical industries, Ltd.) were added to a500 ml eggplant-shaped flask. 1.20g 1% solution of hexahydrohexachloroplatinic (IV) acid hexahydrate in 2-propanol (hereinafter 1% H2PtCl6/6H2O/IPA) was added to this solution and stirred at 50 deg.C for 2H. Thereafter, the reaction mixture was evaporated and dried in vacuo at 35 ℃ for 2 h. The reaction produced 146.05g of product of which about 80% was of formula 3 (above) (wherein R was₂A hydrophilic polysiloxane (designated as H10P16) having a methyl group, m is-20, n is-3, and P is-16). The polysiloxane has an HLB value of about 10 and a hydroxyl content of about 1.2 wt%. The remaining components of the reaction product were about 16% allyl PEG and about 4% PEG.

Example 3: method for making contact lenses using HEMA-compatible polysiloxanes (H10P16)

When the components listed in table 1 were mixed together, a clear composition was formed. The component designated H10P16 was prepared using the method described in example 2 above.

Table 1:

components	Parts per unit by weight
		H10P16	40
HEMA	60
		MA	1.8
TEGDMA	0.1
		V52	0.5
Water (W)	25

The mixtures of table 1 were filled into polypropylene contact lens molds and air cured at 80 ℃ for 1 hour. The mold was opened and the mold half retaining the cured polymeric lens body was immersed in room temperature water for 20 minutes. During this time, the lens hydrates and detaches from the mold half. Subsequently, the lenses were placed in clear water at room temperature for a further 20 minutes, then placed in contact lens blisters containing 1.8ml of PBS, sealed and autoclaved. The resulting lenses were optically clear, had an equilibrium water content of about 55%, a Dk of about 38, and had acceptable physical properties and wettability.

Example 4: method for making contact lenses using HEMA-compatible polysiloxanes (H8P16)

When the components listed in table 2 were mixed together, a clear composition was formed. The component designated H8P16 was prepared using the method described in example 2 above (except that the ratio of reagents was varied to provide a composition having formula 3 (where R is₂Polysiloxane having a structure of methyl, m is-54, n is-7 and p is-17).

Table 2:

components	Parts per unit by weight
		H8P16	40
HEMA	60
		MA	1.8
TEGDMA	0.510 -->
		V52	0.5
Water (W)	25

The mixture of table 2 was filled into contact lens molds, cured and hydrated using the method described in example 3. The resulting lenses were optically clear, had an equilibrium water content of about 56%, a Dk of about 47 and had acceptable physical properties and wettability.

Example 5: process for making dry delensible contact lenses using HEMA-compatible polysiloxanes (H10P16)

When the components listed in table 3 were mixed together, a clear composition was formed. The component designated H10P16 was prepared using the method described in example 2 above.

Table 3:

components

Parts per unit by weight

H10P16	30
		HEMA	50
GMA	15
		MA	2.5
TEGDMA	0.5
		V52	0.8
Water (W)	20

The mixtures of table 3 were filled into polypropylene contact lens molds and air cured at 80 ℃ for 1 hour. The mold is opened and the lens adhered thereto is mechanically removed from the mold halves (i.e., dry delensed). Subsequently, the lenses were placed in PBS for 20 minutes at room temperature, then placed in contact lens blisters containing 1.2ml PBS, sealed and autoclaved. The resulting lenses were optically clear, had an equilibrium water content of about 63%, a Dk of about 40, and had acceptable physical properties and wettability.

Optically clear dry-delensible eyeglasses with the formulations shown in table 4 below were manufactured using the same method as described above for the formulations of table 3.

Table 4:

components	Parts per unit by weight
		H10P16	25
HEMA	70
		GMA	0
MA	4
		TEGDMA	0.5
V52	0.8
		Water (W)	15

Example 6: preparation and purification of HEMA-compatible polysiloxanes (H10P16)

41.67g of the intermediate siloxane of formula 2, 89.10g of hydroxypolyethyleneglycol allyl ether having an average molecular weight of about 750 (UnioxPKA5004, Nippon grease Co., Ltd.), 83.34g of 2-propanol (super-dehydrated grade) (Wako pure chemical industries, Ltd.), 0.40g of 10% ethanol solution of potassium acetate (Wako pure chemical industries, Ltd.), 0.50g of 1% 2-propanol solution of butylated hydroxytoluene (hereinafter, 1% BHT/IPA) and 0.24g of 1% 2-propanol solution of 6-methoxyquinoline (hereinafter, 1% MQ/IPA) were added to a 300ml eggplant-shaped flask. 0.80g of 1% H2PtCl6/6H2O/IPA was added to this solution and stirred at 50 ℃ for 2H. Thereafter, 0.8184g of 1% NaHCO were added₃The aqueous solution was stirred at room temperature for 1 hour. Subsequently, the reaction mixture was evaporated and dried under vacuum at 35 ℃.

The crude mixture was dissolved in 200g of dichloromethane and 135gDI water was added. The solution was vigorously stirred and then centrifuged at 1500rpm for 5 minutes at 20 ℃. After that, the upper layer is removed. This operation was repeated 4 times. 135g of 1% aqueous NaCl solution were added to the organic layer. The solution was vigorously stirred and then centrifuged at 1500rpm for 5 minutes at 20 ℃. Then, the upper layer is removed. This operation was repeated 13 times. Using Na₂SO₄The organic layer was dried and filtered. The filtrate was evaporated and dried in vacuo. 0.24g 1% BHT/IPA and 0.13g 1% MQ/IPA were added to this solution and the solution was subsequently evaporated and dried in vacuo at 35 ℃.

The reaction yielded 73.83g of a compound having formula 3 (above) (where R is₂A hydrophilic polysiloxane (designated as H10P16) having a methyl group, m is-20, n is-3, and P is-16).

Example 7: preparation of HEMA-compatible polysiloxanes (H15E75)

202.20g octamethylcyclotetrasiloxane (LS8620, shin-Etsu chemical Co., Ltd.), 32.78g1,3,5, 7-tetramethylcyclotetrasiloxane (LS8600, shin-Etsu chemical Co., Ltd.), and 58.61g1, 3-bis (3-methacryloxypropyl) -1,1,3, 3-tetramethyldisiloxane (X-22-164, shin-Etsu chemical Co., Ltd.) were added to a500 ml Kyoda flask. 0.62g of trifluoromethanesulfonic acid (Wako pure chemical industries, Ltd.) was added to the solution and stirred at 35 ℃ for 5 hours. Thereafter, 0.7055g of magnesium oxide (light) (Wako pure chemical industries, Ltd.) and 100ml of hexane (anhydrous) were added and stirred at room temperature for 1 hour. The reaction mixture was suction-filtered through No. 545 diatomaceous earth (Wako pure chemical industries, Ltd.) and No. 5A KIRIYAMA filter paper. The filtrate was evaporated and dried in vacuo at 35 ℃. The reaction mixture was then gradually heated to 165 ℃ over 30 minutes at 1mmHg with stirring and low molecular impurities were removed from the organic phase under reduced pressure (1mmHg) and 165 ℃ over 2 h. The reaction yielded 264.48g of the intermediate siloxane of formula 2.

The following were added to a 200ml eggplant-shaped flask: 10.42g of the intermediate siloxane of formula 2, 33.43g of polyethylene-polypropylene glycol allyl ether (UnioxPKA5004, Nippon oil Co., Ltd.), a polyethylene glycol-polypropylene glycol allyl ether having an average molecular weight of about 750 and a random copolymer EO/PO molar ratio of about 75:20, respectively, 30.01g of 2-propanol (super-dehydrated grade) (Wako pure chemical industries, Ltd.), 0.10g of a solution of 10% potassium acetate in ethanol (Wako pure chemical industries, Ltd.), 0.15g of a solution of 1% butylated hydroxytoluene in 2-propanol, and 0.08g of a solution of 1% p-methoxyphenol in 2-propanol (Wako pure chemical industries, Ltd.). 0.20g of 1% H2PtCl6/6H2O/IPA was added to this solution and stirred at 50 ℃ for 2H; after stirring for 1H, 0.2g of 1% H2PtCl6/6H2O/IPA was added. Subsequently, the reaction mixture was evaporated and dried in vacuo. 0.07g 1% BHT/IPA and 0.03g 1% MQ/IPA were added to the dry reaction mixture and the solution was again dried in vacuo. The reaction yielded 22.6069g of a compound having formula 4 (above) (where R is₂Is methyl, k is 0, m is-15, n is-3, p is-12, q is-4 and R₁Hydrogen) structure (designated as H15E75-2 k). What is needed isThe polysiloxane has an HLB value of about 2.8 and a hydroxyl content of about 1.2 wt%.

Example 8: process for preparing polysiloxane intermediates

139.68g of 1,3,5, 7-tetramethylcyclotetrasiloxane (LS8600, shin-Etsu chemical Co., Ltd.) and 30.00g of 1, 3-bis (3-methacryloxypropyl) -1,1,3, 3-tetramethyldisiloxane (X-22-164, shin-Etsu chemical Co., Ltd.) were added to a500 ml Kyoda flask. 0.60g of trifluoromethanesulfonic acid (Wako pure chemical industries, Ltd.) was added to the solution and stirred at 35 ℃ for 24 hours. Thereafter, 0.70g of magnesium oxide (light) (Wako pure chemical industries, Ltd.) and 150ml of hexane (anhydrous) were added and stirred at room temperature for 1 hour. The reaction mixture was suction-filtered through No. 545 diatomaceous earth (Wako pure chemical industries, Ltd.) and No. 5A KIRIYAMA filter paper. The filtrate was evaporated and dried in vacuo at 35 ℃. Then, under reduced pressure (2-3 mmHg), the reaction mixture is gradually heated to 100 ℃ while stirring, and low molecular impurities are removed from the organic phase at 100 ℃ for 2h and subsequently at 120 ℃ for 1 h. The reaction yielded 157.86g of the intermediate siloxane of formula 5.

Example 9: preparation of HEMA-compatible polysiloxane (H30P1-5K-NDM)

15.00g of intermediate siloxane of formula 5, 32.75g of 2- (allyloxy) ethanol (Wako pure chemical industries, Ltd.), 45.02g of 2-propanol (super-dehydrated grade) (Wako pure chemical industries, Ltd.), 0.30g of 10% ethanol solution of potassium acetate, 1.15g of 1% BHT/IPA and 0.08g of 1% MQ/IPA were added to a 300ml eggplant-shaped flask. 0.60g of 1% H2PtCl6/6H2O/IPA was added to this solution and stirred at 50 ℃ for 13.5H. Thereafter, the reaction mixture was evaporated and dried under vacuum at 45 ℃. 0.19g 1% BHT/IPA and 0.09g 1% MQ/IPA were added to this mixture and subsequently evaporated and dried in vacuo at 45 ℃. The reaction yielded 35.1547g of a compound having formula 3 (above) (where R is₂Polysiloxane (designated as H30P1-5K-NDM) with a structure of methyl, m is 0, n is-30 and P is 1). The polysiloxane has an HLB value of about 7 and a hydroxyl content of about 9.7 wt%.

Example 10: preparation of HEMA-compatible polysiloxanes (H30AA-5K)

10.02g of intermediate siloxane of formula 5, 15.52g of allyl alcohol (Wako pure chemical industries, Ltd.), 25.04g of 2-propanol (super-dehydrated grade) (Wako pure chemical industries, Ltd.), 0.20g of 10% ethanol solution of potassium acetate, 0.10g of 1% BHT/IPA and 0.05g of 1% MQ/IPA were added to a 300ml eggplant-shaped flask. 0.40g of 1% H2PtCl6/6H2O/IPA was added to this solution and stirred at 50 ℃ for 13.5H. Thereafter, 0.4128g of 1% aqueous NaHCO3 solution were added and stirred at room temperature for more than 1 h. Subsequently, the reaction mixture was evaporated and dried under vacuum at 35 ℃. About 5g of acetone and 15gDI water were added to this mixture with vigorous shaking. The mixture was then centrifuged (7000rpm, 5 ℃,10 min). The upper layer (aqueous layer) was removed. This operation was repeated 3 times in total. 5g IPA was added to this mixture and the reaction mixture was evaporated and dried in vacuo at 40 ℃. Subsequently, 0.06g 1% BHT/IPA and 0.03g 1% MQ/IPA were added and subsequently evaporated and dried in vacuo at 45 ℃. The reaction yielded 16.6762g of a compound having formula 3 (above) (where R is₂Polysiloxane (named H30AA-5K) with a structure of methyl, m is 0, n is-30 and p is 0). The polysiloxane has an HLB value of about 3 and a hydroxyl content of about 13 wt%.

While the disclosure herein makes reference to specific illustrative examples, it should be understood that these examples are presented by way of example and not limitation of the invention. While exemplary examples have been discussed, the intent of the previous detailed description should be understood to cover all modifications, alternatives, and equivalents of the examples which may be within the spirit and scope of the invention as defined by the additional disclosure.

Numerous publications and patents have been cited above. The cited publications and patents are each incorporated herein by reference in their entirety.

The present invention additionally provides:

1. an optically clear silicone hydrogel contact lens, comprising a polymer lens body that is a reaction product of a polymerizable composition comprising: a) at least 25% by weight of at least one hydroxyalkyl methacrylate; and b) at least 20 wt.% of at least one HEMA-compatible bifunctional polysiloxane comprising at least 6 siloxane groups, wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 5, or has a hydroxyl group content of at least 1 wt.%, or has an HLB value of at least 5 and has a hydroxyl group content of at least 1 wt.%.

2. The contact lens of 1, wherein the HEMA-compatible bifunctional polysiloxane has a molecular weight of 1K to 20K.

3. The contact lens of 1 or 2, wherein the HEMA-compatible bifunctional polysiloxane has an elemental silicon content of at least 10 wt.%.

4. The contact lens of any one of claims 1-3, wherein the HEMA-compatible bifunctional polysiloxane has the structure of formula 4 (above), wherein R₁And R₂Independently selected from hydrogen or methyl, k is an integer of 0 or 1, m is 0 or an integer of at least 1, 6, 10, 15, 20 or 30 to about 50, 60, 80, 100 or 160, n is an integer of at least 1, 2,4, 6,8, 10, 12, 15, 20 or 30 to about 6, 10, 20, 30, 40, 60, 75 or 80, p is 0 or an integer of at least 1, 2,4, 6,8, 10, 12 or 15 to about 18, 20, 30, 40 or 60 and q is 0 or an integer of at least 1, 2,4 or 6 to about 8, 10, 15 or 20.

5. The contact lens of any one of claims 1-4, wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 7.

6. The contact lens of any one of claims 1-4, wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of less than 5 and a hydroxyl content of at least 1 wt.%.

7. The contact lens of any one of claims 1-4, wherein the HLB value is 2 to 4 and hydroxyl content is 4 to 8 wt%.

8. The contact lens of any one of claims 1 to 7, wherein the polymerizable composition further comprises: c)1 to 65 weight percent of a diluent, wherein the weight percent of the diluent is based on the total weight of the polymerizable composition, and wherein the diluent comprises water, low molecular weight polyethylene glycol (PEG), or a combination thereof.

9. The contact lens of any one of claims 1 to 8, wherein the polymerizable composition further comprises at least 0.1% to about 5% methacrylic acid or acrylic acid.

10. The contact lens of any one of claims 1 to 9, wherein the polymerizable composition comprises at least 35 wt.% of a hydroxyalkyl methacrylate.

11. The contact lens of any one of claims 1 to 9, wherein the hydroxyalkyl methacrylate is 2-hydroxyethyl methacrylate (HEMA).

12. The contact lens of any one of claims 1 to 11, having a Dk of at least 35.

13. The contact lens of any one of claims 1 to 11, wherein the polymerizable composition comprises a monomer selected from the group consisting of methacrylic acid, acrylic acid, glycerol methacrylate, and combinations thereof.

14. The contact lens of 13, wherein the polymerizable composition optionally comprises a crosslinker, a polymerizable dye, or both a crosslinker and a polymerizable dye, without other polymerizable components.

15. A method of manufacturing an optically clear contact lens according to any one of claims 1 to 14, comprising: a) polymerizing the polymerizable composition to form a polymeric lens body; and b) hydrating the polymeric lens body, wherein the polymerizable composition is free of diluent or comprises about 1 to 65 wt% of a diluent consisting essentially of water or low molecular weight PEG, or a combination thereof, wherein the wt% of the diluent is based on the total weight of the polymerizable composition.

16. The method of 15, wherein the polymeric lens body is not contacted with a volatile organic solvent during the hydrating step.

17. The method of claim 15 or 16, wherein the polymerizing step comprises heat curing in air.

18. The method of any one of claims 15-17, wherein the polymerizable composition is cured in a mold to form a polymeric lens body, and wherein the polymeric lens body is dry delensed from the mold followed by hydration of the polymeric lens body.

19. A HEMA-compatible polysiloxane having the structure of formula 4 (above), wherein R₁Is hydrogen, R₂Is hydrogen or methyl, k is an integer of 0 or 1, m is an integer of 0 or 1 or 6 to 10, 30, 50 or 60, n is an integer of at least 1, 2,4, 6,8, 10, 12, 15, 20 or 30 to about 6, 10, 20, 30, 40, 60, 75 or 80, p is 0 or an integer of at least 1, 2,4, 6,8, 10, 12 or 15 to about 18, 20, 30, 40 or 60 and q is 0 or an integer of at least 1, 2,4 or 6 to about 8, 10, 15 or 20, wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 5, or has a hydroxyl content of at least 1 wt% (based on the average molecular weight of the polysiloxane), or has an HLB value of at least 5 and has a hydroxyl content of at least 1 wt%, and wherein the HEMA-compatible bifunctional polysiloxane has a purity of at least 75%.

20. The HEMA-compatible polysiloxane of 19, having a purity of at least 90%.

21. The HEMA-compatible polysiloxane of 19 or 20, wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 7.

22. The HEMA-compatible polysiloxane of 19 or 20, wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of less than 5 and a hydroxyl content of at least 1 wt.%.

23. The HEMA-compatible polysiloxane of 19 or 20, wherein the HLB value is 2 to 4 and hydroxyl content is 4 to 8 weight percent.

24. The HEMA-compatible polysiloxane of 19 or 20, wherein k is 0.

25. A method of purifying a polysiloxane from a reaction product comprising the polysiloxane and an unreacted polyethylene glycol-containing reagent, the method comprising: a) combining the reaction product with an organic solvent and water or an aqueous solution to produce a mixture; b) equilibrating the mixture to separate into an organic layer and an aqueous layer; and c) discarding the aqueous layer from the organic layer.

26. The method of 25, further comprising: d) combining the organic layer of step (c) with water or an aqueous solution and repeating the equilibration step and the discard step one or more times.

27. The method of 25 or 26, wherein the equilibrating step comprises centrifuging the mixture.

28. The method of any one of claims 25 to 27, comprising separating the polysiloxane from an organic layer.

Claims (21)

1. An optically clear silicone hydrogel contact lens, comprising:

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

a) at least 25% by weight of at least one hydroxyalkyl methacrylate; and

b) at least 20% by weight of at least one HEMA-compatible bifunctional polysiloxane comprising at least 6 siloxane groups,

wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 7,

wherein the weight% of the hydroxyalkyl methacrylate and the HEMA-compatible difunctional polysiloxane are based on the total weight of polymerizable monomers in the composition.

2. The contact lens of claim 1, wherein the HEMA-compatible bifunctional polysiloxane has the structure of formula 4:

wherein R is₁And R₂Independently selected from hydrogen or methyl, k is an integer of 0 or 1, m is an integer of 0 to 160, n is an integer of 1 to 75, p is an integer of at least 6 and q is an integer of 0 to 20.

3. The contact lens of claim 1, wherein the HEMA-compatible bifunctional polysiloxane has a hydroxyl content of at least 1 weight percent based on the average molecular weight of the polysiloxane.

4. The contact lens of claim 1, wherein the polymerizable composition further comprises:

c)1 to 65 weight percent of a diluent, wherein the weight percent of the diluent is based on the total weight of the polymerizable composition, and wherein the diluent comprises water, low molecular weight polyethylene glycol (PEG), or a combination thereof.

5. The contact lens of claim 4, wherein the HEMA-compatible bifunctional polysiloxane requires the addition of water for optical clarity.

6. The contact lens of claim 1, wherein the polymerizable composition comprises 0.1 wt% to 5 wt% methacrylic acid or acrylic acid.

7. The contact lens of claim 1, wherein the polymerizable composition comprises at least 35 wt.% of a hydroxyalkyl methacrylate.

8. The contact lens of claim 1, wherein the hydroxyalkyl methacrylate is 2-hydroxyethyl methacrylate (HEMA).

9. The contact lens of claim 1 having a Dk of at least 35.

10. The contact lens of claim 1, wherein the polymerizable composition comprises a monomer selected from methacrylic acid, acrylic acid, glycerol methacrylate, and combinations thereof.

11. The contact lens of claim 10, wherein the polymerizable composition optionally comprises a crosslinker, a polymerizable dye, or both a crosslinker and a polymerizable dye, and no other polymerizable components.

12. A method of manufacturing the optically clear contact lens of claim 1, comprising:

a) polymerizing the polymerizable composition to form the polymeric lens body; and

b) hydrating the polymeric lens body and allowing the polymeric lens body to hydrate,

wherein the polymerizable composition is free of diluent or comprises 1 wt% to 65 wt% of a diluent consisting essentially of water or low molecular weight PEG, or a combination thereof, wherein the wt% of the diluent is based on the total weight of the polymerizable composition.

13. The method of claim 12, wherein the polymerizable composition is cured in a mold to form the polymer lens body, and wherein the polymer lens body is dry delensed from the mold followed by hydration of the polymer lens body.

14. A HEMA-compatible polysiloxane having the structure of formula 4,

wherein R is₁Is hydrogen, R₂Is hydrogen or methyl, k is 0 or an integer of 1, m is an integer from 0 to 60, n is an integer from 1 to 75, p is an integer from 0 to 40 and q is an integer from 0 to 20,

wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 7, and

wherein the HEMA-compatible bifunctional polysiloxane has a purity of at least 75%.

15. The HEMA-compatible polysiloxane of claim 14, wherein m is an integer from 6 to 60, n is an integer from 1 to 10, p is an integer from 10 to 30, and q is 0.

16. The HEMA-compatible polysiloxane of claim 14, wherein m is 0, n is an integer from 10 to 60, p is an integer from 0 to 6, and q is 0.

17. The HEMA-compatible polysiloxane of claim 16, wherein n is an integer from 20 to 40 and p is 0.

18. The HEMA-compatible polysiloxane of claim 14, wherein m is an integer from 6 to 60, n is an integer from 1 to 10, p is an integer from 1 to 40, and q is an integer from 1 to 10.

19. The HEMA-compatible polysiloxane of claim 14, wherein m is an integer from 6 to 50, n is an integer from 1 to 6, p is an integer from 8 to 20, and q is an integer from 2 to 8.

20. The HEMA-compatible polysiloxane of claim 14, having a purity of at least 90%.

21. The HEMA-compatible polysiloxane of claim 14, wherein k is 0.