HK1249934B - Contact lens packaging and method for manufacturing same - Google Patents

Description

Contact lens packaging and manufacturing method thereof

Technical Field

The present invention relates to contact lens packaging and a method for making the same.

Background Art

Conventionally, contact lens packaging has been proposed using a packaging solution for hydrophobic contact lenses containing polysorbate or poloxamer as a surfactant (see, for example, Patent Document 1). This packaging solution can substantially prevent contact lenses from adhering to the surface of the packaging material. Furthermore, contact lens packaging has been proposed in which soft lenses are stored in a packaging solution containing methylcellulose as a surfactant (see, for example, Patent Document 2). This packaging solution can inhibit soft lenses from adhering to the hydrophobic packaging material.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application No. 2004-523777

Patent Document 2: Japanese Patent Application No. 2007-512554

Summary of the Invention

Problems to be solved by the invention

However, the packaging solution of Patent Document 1 has the problem of being unable to prevent soft lenses from sticking to the packaging container. Furthermore, the methylcellulose used as a surfactant in Patent Document 2 has low solubility in water, requiring heating for dissolution. Furthermore, there are problems with contamination of impurities and poor filterability, making production difficult.

Furthermore, in recent years, research has been underway into silicone hydrogel contact lenses, which have a lower elastic modulus (Young's modulus) and are more flexible, to improve wearability. This flexibility increases the contact area between these materials and the packaging, making them more susceptible to adhesion to, for example, highly hydrophobic packaging, increasing the potential for deformation or damage to the contact lenses.

The present invention has been made in view of the above problems, and its main object is to provide a contact lens package and a method for producing the same, which have an excellent effect of inhibiting adsorption of silicone hydrogel contact lenses to a packaging container formed of polypropylene.

Means for solving problems

As a result of intensive studies to achieve the above-mentioned object, the present inventors discovered that the use of a packaging solution containing a desired amount of a predetermined nonionic surfactant exhibits an excellent adsorption inhibitory effect, thereby completing the present invention.

That is, the contact lens package of the present invention comprises:

Silicone hydrogel contact lenses,

Packaging container formed of polypropylene, and

A packaging solution containing a nonionic surfactant having a linear alkyl moiety having 12 or more carbon atoms and an ethylene oxide moiety, wherein the average number of added moles of the ethylene oxide per mole of the nonionic surfactant is 30 or more.

The method for manufacturing a contact lens package of the present invention comprises the following steps:

A silicone hydrogel contact lens and a packaging solution are enclosed in a packaging container formed of polypropylene. The packaging solution contains a nonionic surfactant having a linear alkyl moiety having 12 or more carbon atoms and an ethylene oxide moiety, wherein the average number of added moles of the ethylene oxide per mole of the nonionic surfactant is 30 or more.

Effects of the Invention

In the contact lens packaging and manufacturing method of the present invention, the adhesion (adsorption) of silicone hydrogel contact lenses to the packaging container formed by polypropylene can be further suppressed. It is speculated that the reason is that, for example, the non-ionic surfactant has a straight-chain alkyl portion with a carbon number of 12 or more, and the average number of added moles of ethylene oxide is 30 or more, so it has good compatibility with the hydrophobic part of the silicone hydrogel. Generally, silicone hydrogel has strong hydrophobicity, so it is speculated that it interacts strongly with the hydrophobic part of the non-ionic surfactant in water. It is speculated that the surfactant attracted by the lens surface will face the hydrophilic unit toward the surface (in the liquid), and as a result, it can impart hydrophilicity to the lens surface. However, when the hydrophilicity of the non-ionic surfactant is too strong, the surfactant itself will not be attracted by the lens itself, making it difficult to impart hydrophilicity to the lens surface. On the other hand, when the hydrophobicity of the non-ionic surfactant is too strong, although the surfactant itself can be firmly attached to the lens, it is difficult to impart sufficient hydrophilicity to the lens. Therefore, the balance of these hydrophobicity and hydrophilicity is very important. In the present invention, the nonionic surfactant has a good balance between the hydrophobicity and the hydrophilicity, and therefore is presumed to effectively exhibit the adsorption inhibitory effect.

DETAILED DESCRIPTION

The contact lens package of the present invention comprises a silicone hydrogel contact lens, a packaging container made of polypropylene, and a packaging solution containing a nonionic surfactant. The nonionic surfactant in the packaging solution comprises a linear alkyl moiety having 12 or more carbon atoms and an ethylene oxide moiety, with the average number of added moles of ethylene oxide per mole of the nonionic surfactant being 30 or more. It should be noted that the term "linear alkyl moiety" refers to a structure in which carbon atoms are linked in a chain, rather than a cyclic or branched structure.

As silicone hydrogel contact lenses, known silicone hydrogel contact lenses can be used. For example, silicone hydrogel contact lenses include polymers containing silicone monomers copolymerized with hydrophilic monomers. Examples of materials for making such silicone hydrogels include acquafilcon A, asmofilcon A, balafolcon A, comfilcon A, enfilcon A, galyfilcon A, lenefilcon A, lotorafilcon A, lotorafilcon B, senofilcon A, comfilcon A, stenfilcon A, and narafilcon A. Examples of silicone monomers contained in silicone hydrogels include 3-(meth)acryloxypropyl tris(trimethylsiloxy)silane, mono(meth)acryloxypropyl-terminated polydimethylsiloxane, 3-(meth)acryloxypropyl-bis(trimethylsiloxy)methylsilane, and (meth)acryloxypropyl pentamethyldisiloxane. 3-Methacryloxypropyltris(trimethylsiloxy)silane (TRIS) is more preferred because it has excellent compatibility with other monomers, can be distilled, and can easily obtain a highly pure monomer.

In addition, as materials for making silicone hydrogels, silicone macromonomers can be cited, for example. As the silicone macromonomer, it can be a compound having, for example, a polyurethane structure, an ethylenically unsaturated structure, a polydimethylsiloxane structure, and a polymeric group. The polymeric group can be, for example, one or more of an acryloyl group and a methacryloyl group. The silicone macromonomer can have, for example, a structure of chemical formula (1). Here, in formula (1), c is preferably 30 or more and 50 or less. As examples of the silicone macromonomer, compounds represented by chemical formula (2) can be cited. Alternatively, the silicone macromonomer can be a compound represented by chemical formula (3).

[Chemistry 1]

[Chemistry 2]

[Chemistry 3]

Examples of hydrophilic monomers included in the silicone hydrogel include unsaturated carboxylic acids such as methacrylic acid and acrylic acid, acrylic acid-substituted alcohols such as 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate, vinyl lactams such as 1-methyl-3-methylene-2-pyrrolidone and N-vinylpyrrolidone, acrylamides such as methacrylamide and N,N-dimethylacrylamide, and (meth)acrylates having a polyethylene glycol moiety. Among these, N-vinylpyrrolidone, N,N-dimethylacrylamide, and 1-methyl-3-methylene-2-pyrrolidone are preferred because they have excellent compatibility with other monomers and can impart high hydrophilicity to the hydrophobic silicone hydrogel with a small amount.

The Young's modulus of the silicone hydrogel contact lens is preferably 1.2 MPa or less. When the Young's modulus is 1.2 MPa or less, the lens is soft and can further suppress congestion caused by friction between the lens and the eye surface, so it is preferred. From the perspective of further improving the wearing experience, the Young's modulus is more preferably 1.1 MPa or less. In addition, when the Young's modulus of the silicone hydrogel contact lens exceeds 1.2 MPa, especially when it is above 1.4 MPa, the lens is relatively hard and the contact area with the packaging container is not easy to increase, so it is not easy for the contact lens to adhere to the packaging container. For the contact lens packaging of the present invention, a Young's modulus of less than 1.4 MPa is more effective for softer silicone hydrogel contact lenses.

The silicone hydrogel contact lens may be subjected to a surface modification treatment. The surface modification treatment can further improve the water wettability of the surface of the silicone hydrogel contact lens. As a surface modification treatment, for example, low-temperature plasma treatment, atmospheric pressure plasma, corona discharge, and the like, which are well known to those skilled in the art, may be applied. The surface modification treatment may be performed under reduced pressure or at atmospheric pressure. For example, in low-temperature plasma treatment performed under reduced pressure, one or more of alkanes having 1 to 6 carbon atoms, fluorine-substituted alkanes, _O₂ , _N₂ , _CO₂ , argon, hydrogen, air, and water vapor may be used as a carrier gas.

While polypropylene, polyethylene, nylon, olefins, copolymers, acrylic resins, rubber, polyurethane, polycarbonate, or fluorocarbon resins have been studied as packaging containers, polypropylene is preferred due to its low water vapor permeability, resistance to high-pressure steam sterilization, durability, low raw material costs, and transparency. A housing for silicone hydrogel contact lenses is formed within the packaging container. Furthermore, contact lens packaging preferably includes a cover sheet that covers the lens housing opening of the packaging container and seals it fluid-tight. It should be noted that the cover sheet is preferably formed from a laminated sheet, for example, comprising a composite material comprising aluminum foil and a synthetic resin laminated in layers or foils.

The packaging solution contains a nonionic surfactant comprising a linear alkyl moiety having 12 or more carbon atoms and an ethylene oxide moiety, wherein the average number of added moles of ethylene oxide per mol of the nonionic surfactant is 30 or more. The inclusion of such a nonionic surfactant in the packaging solution can further suppress adhesion of silicone hydrogel contact lenses to packaging containers. For this nonionic surfactant, a linear alkyl moiety having 12 or more carbon atoms exhibits sufficient hydrophobicity, which is also preferred from the perspective of availability. This carbon number is more preferably 15 or more, and even more preferably 17 or more. Furthermore, from the perspective of ease of solubility in solution, this carbon number is preferably 20 or less. Silicone hydrogels have a hydrophobic portion, so in order to exhibit an effect that inhibits adsorption between contact lenses and packaging containers, it is preferable to have a linear alkyl moiety that exhibits a certain degree of hydrophobicity. To achieve the desired sufficient hydrophobicity, the alkyl chain preferably has 12 or more carbon atoms and 20 or less carbon atoms. In addition, from the viewpoint of easy solubility in a solution and imparting hydrophilicity, the average number of moles of ethylene oxide added to the nonionic surfactant is preferably 30 or more, more preferably 40 or more. From the viewpoint of easy availability, the average number of moles of ethylene oxide added is preferably 100 or less. Examples of such nonionic surfactants include polyoxyethylene-hydrogenated castor oil. Examples of such polyoxyethylene-hydrogenated castor oils include polyoxyethylene-hydrogenated castor oil 40 (average number of moles of ethylene oxide added = 40), polyoxyethylene-hydrogenated castor oil 60 (average number of moles of ethylene oxide added = 60), and polyoxyethylene-hydrogenated castor oil 100 (average number of moles of ethylene oxide added = 100).

The packaging solution preferably contains a nonionic surfactant in a range of 0.001% to 0.1% by mass. A content of 0.001% by mass or greater can significantly inhibit adsorption of the contact lens to the packaging container. To achieve the desired effect, this content is more preferably 0.005% by mass or greater. Furthermore, a content of 0.1% or less will not be excessive, further suppressing blistering and facilitating manufacturing. This is also preferred because it can inhibit excessive swelling of the contact lens, making it easier to remove the contact lens from the packaging container. A more preferred content is 0.08% by mass or less.

In addition to the nonionic surfactant described above, the packaging solution may contain other substances that can be added to the packaging solution, as long as the effects of the present invention are not impaired. Examples of such added substances include chelating agents, isotonicity agents, pH adjusters, buffers, surfactants, thickeners, preservatives (preservatives), and wetting agents. These substances may be added to the packaging solution alone or in combination of two or more.

Examples of chelating agents include ethylenediaminetetraacetic acid (EDTA) and its hydrates, disodium ethylenediaminetetraacetate (EDTA-2Na) and its hydrates, trisodium ethylenediaminetetraacetate (EDTA-3Na) and its hydrates, tetrasodium ethylenediaminetetraacetate (EDTA-4Na) and its hydrates, phytic acid, and citric acid. The amount of the chelating agent in the packaging solution is preferably in the range of 0% by mass or more and 1.0% by mass or less. When the amount is 1.0% by mass or less, the user is less likely to experience eye problems when using contact lenses. Furthermore, the amount is preferably 0.001% by mass or more. When the amount is 0.001% by mass or more, the chelating agent's effect can be further enhanced.

As isotonic agents, for example, glycerol, propylene glycol, sodium chloride, potassium chloride, sorbitol, mannitol, etc. can be mentioned. The compounding amount of the isotonic agent in the packaging solution is preferably in the range of 0 mass % or more and 2.0 mass % or less. When the compounding amount is below 2.0 mass %, it is safe for the eyes and is not easy to cause eye irritation or foreign body sensation when the user uses contact lenses. In addition, the compounding amount is preferably above 0.01 mass %. When the compounding amount is above 0.01 mass %, the effect of the isotonic agent can be further exerted.

Examples of pH adjusters include hydrochloric acid, citric acid, acetic acid, sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate. The amount of the pH adjuster blended into the packaging solution is preferably in the range of 0% by mass to 1.0% by mass. A blending amount of 1.0% by mass or less reduces the risk of eye problems when the user wears contact lenses. Furthermore, the blending amount is preferably 0.01% by mass or greater. A blending amount of 0.01% by mass or greater further enhances the effectiveness of the pH adjuster.

Examples of buffering agents include phosphoric acid, phosphate buffers, boric acid, borax and borate buffers, carbonate buffers, acetic acid, citric acid, ε-aminocaproic acid, 2-amino-2-methyl-1,3-propane (AMP) buffer, tris(hydroxymethyl)aminomethane (Tris) buffer, and bis(2-hydroxyethyl)iminotris(hydroxymethyl)methane (Bis-Tris). The amount of the buffer in the packaging solution is preferably in the range of 0% by mass or more and 2.0% by mass or less. When the amount is 2.0% by mass or less, the eye is safer and is less likely to cause eye irritation or foreign body sensation when the user uses contact lenses. In addition, the amount is preferably 0.01% by mass or more. When the amount is 0.01% by mass or more, the effect of the buffer can be further exerted.

As surfactant, for example, polyglycerol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene/polyoxypropylene block copolymer, polyoxyethylene/polyoxypropylene ethylenediamine, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether formaldehyde condensate, polyoxyethylene alkylphenyl ether, polyoxyethylene glycerol fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene solidified castor oil, polyoxyethylene sterol, polyoxyethylene hydrogenated sterol, polyoxyethylene fatty acid ester, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene lanolin alcohol, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene alkyl ether phosphoric acid, polysorbate etc. can be enumerated.The compounding amount of this surfactant in the packaging solution is preferably the scope of 0 mass % or more and 1.0 mass % or less. When compounding amount is 1.0 mass % or less, it is high for the safety of eyes, is difficult for bringing eye irritation or foreign body sensation when the user uses contact lenses. In addition, this compounding amount is preferably 0.001 mass % or more. When the compounding amount is 0.001 mass % or more, the effect of the surfactant can be further exhibited.

Examples of thickeners include polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polypropylene glycol, polyacrylamide, cellulose derivatives such as hydroxymethylcellulose and hydroxypropylcellulose, starch derivatives, and synthetic organic polymers. The amount of thickener blended into the packaging solution is preferably in the range of 0% by mass to 1.0% by mass. A blending amount of 1.0% by mass or less provides enhanced eye safety and is less likely to cause eye irritation or foreign body sensation when the user wears contact lenses. Furthermore, the blending amount is preferably 0.01% by mass or greater. A blending amount of 0.01% by mass or greater further enhances the effectiveness of the thickener.

As the preservative (preservative), for example, sorbic acid, potassium sorbate, benzalkonium chloride, benzethonium chloride, methylparaben, propylparaben, chlorobutanol, etc. can be enumerated. The compounding amount of the preservative in the packaging solution is preferably in the range of 0 mass % or more and 1.0 mass % or less. When the compounding amount is below 1.0 mass %, it is high for the safety of the eyes and is difficult to bring about eye irritation or foreign body sensation when the user uses contact lenses. In addition, the compounding amount is preferably above 0.01 mass %. When the compounding amount is above 0.01 mass %, the effect of the preservative can be further brought into play.

Examples of wetting agents include glycerin, polyethylene glycol, propylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, cationic cellulose polymers, hydroxypropyl methylcellulose, hydroxyethyl cellulose, and methylcellulose. The amount of the wetting agent blended into the packaging solution is preferably in the range of 0% by mass to 1.0% by mass. A blending amount of 1.0% by mass or less provides enhanced eye safety and is less likely to cause eye irritation or a foreign body sensation when the contact lens is used. Furthermore, the blending amount is preferably 0.01% by mass or greater. A blending amount of 0.01% by mass or greater further enhances the wetting agent's effectiveness.

The difference in specific gravity between the packaging solution and the silicone hydrogel contact lens at 20°C is preferably 0.1 or less. Within this specific gravity difference range, deformation caused by the silicone hydrogel contact lens floating out of the packaging solution and coming into contact with air can be prevented or further suppressed. The specific gravity difference is the value obtained by subtracting the specific gravity of the packaging solution from the specific gravity of the silicone hydrogel contact lens. This specific gravity difference is preferably 0.08 or less, and more preferably 0.06 or less.

The pH of the packaging solution is preferably in the range of 4.0 to 9.0. When the pH of the packaging solution is within this range, for example, degradation of the silicone hydrogel during autoclaving can be further suppressed, and the strength of the silicone hydrogel contact lens can be adequately maintained. For example, the pH range is more preferably in the range of 5.0 to 8.0.

The osmotic pressure of the packaging solution is preferably in the range of 200 mOsm to 500 mOsm, more preferably in the range of 250 mOsm to 400 mOsm. When the osmotic pressure is within this range, it is less likely to cause irritation to the user's eyes and can further prevent problems such as deformation of the contact lens.

The packaging solution is preferably sealed in the packaging container in a range of 0.01 ml to 5.0 ml, more preferably in a range of 0.1 ml to 2.5 ml.

The method for producing a contact lens package of the present invention comprises the steps of enclosing a silicone hydrogel contact lens and a packaging solution in a packaging container made of polypropylene, the packaging solution containing a nonionic surfactant, wherein the nonionic surfactant contains a linear alkyl moiety having 12 or more carbon atoms and an ethylene oxide moiety, and the average number of added moles of ethylene oxide per mole of the nonionic surfactant is 30 or more. In this production method, the aforementioned forms of the silicone hydrogel contact lens, packaging container, and packaging solution can be appropriately adopted.

In the contact lens packaging and manufacturing method of the present embodiment described in detail above, adhesion of the silicone hydrogel contact lens to the packaging container formed from polypropylene can be further suppressed. In addition, since this adhesion can be suppressed, the lens shape can be maintained. Furthermore, deformation or damage caused by adhesion of the contact lens, changes in optical properties, and a reduction in wearing comfort can be more effectively suppressed. The reason for this is presumably as follows. It is presumed that, for example, the nonionic surfactant contained in the packaging solution has a linear alkyl moiety with 12 or more carbon atoms and an average number of added moles of ethylene oxide of 30 or more, and therefore has good compatibility with the hydrophobic portion of the silicone hydrogel. Silicone hydrogels are generally highly hydrophobic, and therefore it is presumed that they interact strongly with the hydrophobic portion of the nonionic surfactant in water. It is therefore presumed that the surfactant attracted to the lens surface directs its hydrophilic units toward the surface (in the liquid), resulting in the lens surface being rendered hydrophilic. However, if the nonionic surfactant is too hydrophilic, the surfactant itself will not be attracted to the lens itself, making it difficult to impart hydrophilicity to the lens surface. On the other hand, if the nonionic surfactant is too hydrophobic, while the surfactant itself can firmly adhere to the lens, it is difficult to impart sufficient hydrophilicity to the lens. The nonionic surfactant in the present invention has a good balance between these hydrophobic and hydrophilic properties, and is therefore believed to effectively inhibit the adsorption of silicone hydrogel to polypropylene packaging containers.

Furthermore, contact lenses are typically designed to precisely match individual users' vision, corneal shape variations, and other factors. In addition to lens diameter (DIA), specifications such as diopter, base curve shape (BC), and various lens sizes are also strictly defined. The contact lens packaging of this embodiment effectively prevents adhesion (adsorption) of silicone hydrogel contact lenses to the packaging container, thereby ensuring long-term lens preservation and preventing lens breakage during user use.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented in various forms as long as it falls within the technical scope of the present invention.

Example

Hereinafter, an example in which the contact lens package of the present invention is specifically produced and used will be described as an embodiment.

[Contact lenses]

As commercial product 1, 1-DAY ACUVUE TruEye manufactured by Johnson & Johnson was used. As a pretreatment, 15 ml of the packaging solution and 5 lenses of commercial product 1 were placed in a screw-mouth bottle SV-20 manufactured by Nippon Glass Co., Ltd., and liquid replacement was performed for more than 3 hours. In addition, contact lenses of materials 1 to 4 were produced as follows. That is, the polymerizable composition mixed as shown in Table 1 was placed in a contact lens mold made of polypropylene in the shape of a contact lens, and for materials 1 and 2, after irradiation with a blue fluorescent lamp for 15 minutes, a high-intensity blue LED lamp was used to irradiate for 15 minutes, thereby producing contact lenses. For materials 3 and 4, ultraviolet light was irradiated for 20 minutes using a high-pressure mercury lamp, thereby producing contact lenses. It should be noted that the polydimethylsiloxane macromonomer containing an urethane bond shown in Table 1 has a structure represented by chemical formula (2). In addition, a plasma generator was used to perform surface modification treatment on the contact lenses of materials 1, 2, and 4. This surface modification treatment was performed using CO ₂ as the carrier gas and at an output of 80 W under reduced pressure. The contact lens of Material 3 was not subjected to surface modification treatment. Separately, a contact lens treated with atmospheric pressure plasma was produced. First, the polymerizable composition of Material 1, mixed as shown in Table 1, was placed in a contact lens-shaped polypropylene contact lens mold. After irradiation with a blue LED lamp for 12 minutes, it was then irradiated with a high-intensity blue LED lamp for 15 minutes to produce a contact lens. This contact lens was subjected to surface modification treatment at atmospheric pressure using an atmospheric pressure plasma treatment apparatus (Material 5).

Materials 1 to 3 were immersed in 2.8 ml/lens of packaging solution and allowed to stand for 3 hours to hydrate the lenses. Material 4 was immersed in 2.2 ml/lens of distilled water for 10 minutes, then immersed in 2.2 ml/lens of distilled water for another 10 minutes, and then immersed in 24-well plates with 2.2 ml/lens of the liquid of Comparative Example 1. They were then sterilized at 121°C for 20 minutes using a high-pressure steam sterilizer SM-22 manufactured by Yamato Scientific Co., Ltd. The lenses of Material 5 were hydrated by swelling them with the packaging solution of the examples shown in Table 2 and distilled water until equilibrium was reached. They were then immersed in the liquid of Example 2 in a contact lens blister and sterilized at 121°C for 20 minutes using a high-pressure steam sterilizer. The resulting lenses were designated as contact lenses of Material 5.

[Table 1]

[Packaging Solutions of Examples 1 to 7]

Packaging solutions for the examples were prepared using the mixing ratios shown in Table 2. Common components included NaCl and propylene glycol (PG) as isotonicity agents, sodium hydrogen phosphate hydrate and sodium dihydrogen phosphate as buffers, and trisodium ethylenediaminetetraacetic acid as a chelating agent. Examples 1 to 4 used polyoxyethylene-solidified castor oil (HCO-60: linear alkyl chain = 17 carbon atoms, average number of added ethylene oxide moles = 60) as the nonionic surfactant. Example 5 used polyoxyethylene-solidified castor oil (HCO-40: linear alkyl chain = 17 carbon atoms, average number of added ethylene oxide moles = 40) as the nonionic surfactant, and Examples 6 and 7 used polyoxyethylene-solidified castor oil (HCO-100: linear alkyl chain = 17 carbon atoms, average number of added ethylene oxide moles = 100) as the nonionic surfactant.

[Packaging Solutions of Comparative Examples 1 to 7]

Comparative Example packaging solutions were prepared using the blending ratios shown in Table 2. A comparative example in which no nonionic surfactant was used was designated as Comparative Example 1. Comparative Examples 2 and 3 were designated as Comparative Examples in which polysorbate 80 (linear alkyl chain = 17 carbon atoms, average number of added ethylene oxide moles = 20) was used as the nonionic surfactant. Comparative Example 4 was designated as Comparative Example 5, in which Koliphor P407 (linear alkyl chain = no carbon atoms, average number of added ethylene oxide moles = 196) was used as the nonionic surfactant. Comparative Example 6 was designated as Comparative Example 7, in which Pluronic P123 (linear alkyl chain = no carbon atoms, average number of added ethylene oxide moles = 42) was used as the nonionic surfactant. Comparative Example 7 is a comparative example in which hydroxypropylmethylcellulose (HPMC) TC-5 (linear alkyl chain = no, average number of added moles of ethylene oxide = 0) was used as a nonionic surfactant.

(Adhesion Evaluation)

2.2 ml of each packaging solution from Examples 1 to 7 or Comparative Examples 1 to 7 was dispensed into 24-well plates made of polypropylene from Evergreen Scientific, and one lens from each of Materials 1 to 5 was impregnated. The 24-well plates, with the impregnated lenses, were sterilized at 121°C for 20 minutes using an SM-22 autoclave manufactured by Yamato Scientific Co., Ltd. After sterilization, the well plates were tilted 30° to evaluate the adhesion of the lenses to the container based on whether the lenses moved. Lenses with a percentage of 20% or less of adherence in each packaging solution were considered acceptable.

(Evaluation of tensile elastic modulus)

Each lens material sterilized in the same manner as the adhesion evaluation was processed into a dumbbell-shaped test piece (parallel portion length 6mm, width 2mm) using a punching blade. The test piece immersed in ISO physiological saline was placed in a constant temperature water bath set at 20°C (actually measured 20.0°C) for state conditioning. The thickness of the state-conditioned test piece was measured using LIGHT MAGIC manufactured by Mitutoyo Corporation. The two ends of the test piece were fixed to the fixture of a Shimadzu precision universal testing machine (automatic plotter AG-IS (MS)) manufactured by Shimadzu Corporation. The test piece was stretched at a tensile speed of 100 mm/min until it broke, the stress at the time of fracture was read, and the tensile modulus of elasticity was calculated from the slope of the tangent line at the deformation starting point of the tensile stress-strain curve.

(Specific Gravity Determination (Lens))

The specific gravity of each lens material was measured using a SARTORIUS specific gravity measuring kit YDK01, sterilized in the same manner as for the adhesion evaluation. First, the immersion liquid was placed in a beaker, maintained at a specified temperature, and placed on a fixed support table so that it did not come into contact with the movable part of the balance. Using the upper weighing pan of the weighing pan mounted on the fixed support table, the mass W1 (g) of the lens in air at 20°C was weighed to the nearest 0.1 mg. Ten lenses of each type were used, and moisture was wiped off the lens surface with absorbent paper before weighing. A thermometer was inserted into the immersion liquid. After confirming that it was at 20°C, it was placed on the lower weighing pan so that no bubbles formed in the lens. The mass W2 (g) in the immersion liquid was weighed to the nearest 0.1 mg. The specific gravity was calculated using the following formula (1) using the density P (g/ ^cm3 ) of the immersion liquid at the specified temperature and the density K (g/ ^cm3 ) of water at the specified temperature.

Specific gravity S = P/K × (W1/(W1-W2)) ... formula (1)

(Specific Gravity Determination (Packaging Solution))

Measure the mass M (g) of the Sprengel.Ostwald pycnometer to the fourth decimal place using an electronic balance. Immerse one capillary tube of the Sprengel.Ostwald pycnometer in the packaging solution, which has been temperature-controlled in a 20°C constant-temperature water bath, for approximately 15 minutes, and draw the liquid up onto the line. After confirming that the constant-temperature water bath set at 20°C has reached the specified temperature, immerse the Sprengel.Ostwald pycnometer in the solution for approximately 15 minutes. Place a piece of filter paper at one end so that the tip of the liquid is aligned with the line. Remove the Sprengel.Ostwald pycnometer from the constant-temperature water bath, wipe the outside clean, and measure the mass M1 (g) using an electronic balance. Perform the same procedure using the same Sprengel.Ostwald pycnometer in pure water to measure the mass M2 (g). Calculate the specific gravity d to the third decimal place using the following formula (2), and the density X at 20°C to the third decimal place using the following formula (3).

Specific gravity d = (M1-M)/(M2-M) ... formula (2)

Density X = 0.99704 × d…Equation (3)

(Results and Investigation)

Table 2 summarizes the composition of the packaging solutions and the percentage of lenses adhering to the packaging solution for the Examples and Comparative Examples. Table 3 summarizes the specific gravity of the lenses, packaging solutions, and the tensile modulus (Young's modulus) of the lenses. As shown in Tables 2 and 3, no adhesion occurred between the packaging container and the contact lens for lenses made with Material 4, regardless of the packaging solution. This is believed to be because the Young's modulus of the lenses made with Material 4 was high, and the contact lens contact area did not increase. On the other hand, adhesion did occur for lenses with a Young's modulus less than 1.4 MPa, but the adsorption inhibition effect was not sufficiently achieved for Comparative Examples 1 to 7. On the other hand, Examples 1 to 7, which used a nonionic surfactant (polyoxyethylene-hardened castor oil) containing a linear alkyl moiety with 12 or more carbon atoms and an ethylene oxide moiety, and with an average added mole number of ethylene oxide of 30 or more, showed an extremely high effect in inhibiting adsorption between the packaging container and the contact lens. Furthermore, the compounding amount of this nonionic surfactant is preferably in the range of 0.001% by mass to 0.1% by mass. Furthermore, it was found that an average addition molar number of ethylene oxide in the nonionic surfactant within the range of 40 to 100 can achieve an adsorption-inhibiting effect. Furthermore, the results of Example 7 demonstrate that even when other surfactants are present, a high adsorption-inhibiting effect can be achieved when the nonionic surfactant of the example is present. Furthermore, the specific gravity difference between the silicone hydrogel contact lens and the packaging solution is preferably 0.1 or less. Furthermore, studies of surface modification treatment conditions revealed that adhesion between the packaging container and the contact lens did not occur in the packaging solutions of the examples, regardless of whether the surface treatment was performed under atmospheric pressure or under reduced pressure. This demonstrates that adhesion can be further suppressed in the packaging solutions of the examples, independent of the surface treatment conditions.

[Table 2]

[Table 3]

Industrial Applicability

The present invention can be used in the technical field of manufacturing and distributing contact lens packages.

Claims (3)

1. A contact lens packaging, comprising: Silicone hydrogel contact lenses Packaging containers made of polypropylene The packaging solution contains a nonionic surfactant comprising a straight-chain alkyl group having 12 or more carbon atoms and an ethylene oxide group, wherein the average molar addition of the ethylene oxide in 1 mole of the nonionic surfactant is 30 or more. The packaging solution contains the nonionic surfactant in an amount ranging from 0.001% to 0.1% by mass. The nonionic surfactant is polyoxyethylene hydrogenated castor oil. The Young's modulus of the silicone hydrogel contact lens is below 1.2 MPa. 2. The contact lens packaging as described in claim 1, wherein, The specific gravity difference between the packaging solution and the silicone hydrogel contact lens is less than 0.1. 3. A method for manufacturing contact lens packaging, wherein, A silicone hydrogel contact lens and a packaging solution are sealed into a packaging container formed of polypropylene. The packaging solution contains a nonionic surfactant containing a straight-chain alkyl group with 12 or more carbon atoms and an ethylene oxide group. The average molar addition of the ethylene oxide in 1 mole of the nonionic surfactant is 30 or more. The packaging solution contains the nonionic surfactant in the range of 0.001% by mass to 0.1% by mass. The nonionic surfactant is polyoxyethylene hydrogenated castor oil. The silicone hydrogel contact lens has a Young's modulus of 1.2 MPa or less.