JP7582298B2 - Agent for suppressing the adsorption of urban airborne particulate matter (PM2.5) and yellow sand for soft contact lenses - Google Patents

Description

The present invention relates to an inorganic microparticle adsorption inhibitor for soft contact lenses, which comprises a copolymer having a specific structure.

The main causes of allergic conjunctivitis in the field of ophthalmology are said to be pollen particles such as cedar pollen and cypress pollen, and house dust. However, due to the influence of recent global air pollution, it has been reported that inorganic fine particulate matter such as yellow sand, PM10, and PM2.5 can also cause allergic conjunctivitis (Non-Patent Documents 1 and 2). These air pollutants adhere to and are adsorbed on the conjunctiva, cornea, etc., causing allergic symptoms, such as congestion, eye discharge, and watery eyes. Therefore, various technical developments have been made to treat, alleviate, and prevent these allergic symptoms. For example, as a pharmaceutical or chemical method, a method of treating or alleviating with medicines or eye drops containing antiallergic drugs (Patent Document 1) is known, and as a physical method, a method of wearing glasses or a mask to suppress contact of air pollutants with the conjunctiva or cornea in the first place (Patent Documents 2 and 3) is known. Although pharmaceutical and chemical methods are highly effective, they are known to cause side effects such as inducing drowsiness. Furthermore, physical methods are effective if used before air pollutants adhere to or are adsorbed onto the conjunctiva or cornea, but are thought to lose their effectiveness once air pollutants adhere to or are adsorbed onto the conjunctiva or cornea.
Furthermore, for soft contact lens wearers, once these air pollutants adhere to and are adsorbed onto the surface of the soft contact lens, it is difficult to wash them off with tears or artificial tears, etc., and there is a concern that allergic symptoms may persist for a long period of time.
For this reason, there has been a demand for the development of technology that can alleviate allergic symptoms and alleviate or reduce discomfort by suppressing the adhesion and adsorption of air pollutants to the conjunctiva, cornea, and even the surface of soft contact lenses. However, sufficient technological development to achieve this has not been carried out, and no effective methods have been known to date.

JP 2018-203791 A JP 2017-134100 A JP 2014-111147 A

Tatsuya Mimura, Topic 1. Allergy and environmental factors in the field of ophthalmology, Allergy, 63(7), 901-906, 2014. Tatsuya Mimura et al., Airborne particulate matter (PM2.5) and the prevalence of allergic conjunctivitis in Japan, Science of the Total Environment, 493-499, 2014

The objective of the present invention is to provide an inorganic microparticle adsorption inhibitor for soft contact lenses that uses inorganic microparticles to inhibit the adsorption of microparticles such as PM10, PM5, and PM2.5 to the surface of soft contact lenses, thereby alleviating and reducing the symptoms of allergic conjunctivitis and improving discomfort.

As a result of intensive research by the present inventors to solve the above problems, it was found that the adsorption of inorganic harmful particles such as PM10, PM5, and PM2.5 can be suppressed by using a material containing a copolymer having a specific weight-average molecular weight and a specific structure for soft contact lenses. As a result, it was found that it is possible to provide an agent for suppressing the adsorption of inorganic particles for soft contact lenses against urban air dust (PM2.5) and yellow sand, which can alleviate and reduce the symptoms of allergic conjunctivitis and further improve discomfort, and thus the present invention was completed.
That is, the inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention , which is an agent for inhibiting adsorption of urban air particulate matter (PM2.5) and yellow sand for soft contact lenses, is as follows.

[1] An agent for suppressing adsorption of urban air particulate matter (PM2.5) and yellow sand for soft contact lenses, comprising a copolymer (P) having a weight average molecular weight of 10,000 to 5,000,000 and containing 10 to 90 mol % of a structural unit (A) based on 2-(meth)acryloyloxyethyl phosphorylcholine and 90 to 10 mol % of at least one structural unit selected from the group consisting of a structural unit (B1) based on an alkyl group-containing (meth)acrylic monomer, a structural unit (B2) based on a quaternary ammonium group-containing (meth)acrylic monomer , and a structural unit (B3) based on a (meth)acrylamide monomer.
(In formula (A), R ¹ represents a hydrogen atom or a methyl group. In formula (B1), R ² represents a hydrogen atom or a methyl group, and R ³ represents an alkyl group having 4 to 18 carbon atoms. In formula (B2), R ⁴ represents a hydrogen atom or a methyl group, R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and X ⁻ represents a halogen ion or an acid residue. In formula (B3), R ⁸ represents a hydrogen atom or a methyl group, and R ⁹ and R ¹⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)

By using the inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention, it is possible to suppress the adsorption of inorganic fine particles such as PM2.5, PM5, and PM10 after wearing soft contact lenses, thereby alleviating and reducing the symptoms of allergic conjunctivitis and improving discomfort.

The inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention contains a copolymer (P).
The present invention will be described in detail below.
In this specification, when a preferred numerical range (e.g., a range of concentration or weight average molecular weight) is described in stages, each lower limit and upper limit can be combined independently. For example, in the description "preferably 10 or more, more preferably 20 or more, and preferably 100 or less, more preferably 90 or less," the "preferable lower limit: 10" and the "more preferable upper limit: 90" can be combined to obtain "10 or more and 90 or less." For example, in the description "preferably 10 to 100, more preferably 20 to 90," the range can be similarly set to "10 to 90."
In the present invention, "(meth)acrylic" means acrylic or methacrylic (methacrylic), "(meth)acryloyl" means acryloyl or methacryloyl (methacryloyl), and "(meth)acrylate" means acrylate or methacrylate (methacrylate).

<Adsorption inhibitor for inorganic fine particles for soft contact lenses>
The inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention contains a copolymer (P) containing a structural unit (A) based on 2-(meth)acryloyloxyethyl phosphorylcholine and at least one structural unit selected from the group consisting of a structural unit (B1) based on an alkyl group-containing (meth)acrylic monomer, a structural unit (B2) based on a quaternary ammonium group-containing (meth)acrylic monomer, and a structural unit (B3) based on a (meth)acrylamide monomer.

式（Ａ）及び式（Ａ’）において、Ｒ^１は水素原子もしくはメチル基のいずれでも良いが、好ましくはメチル基である。 <Structural Unit (A) Based on 2-(meth)acryloyloxyethylphosphorylcholine>
The structural unit (A) based on 2-(meth)acryloyloxyethyl phosphorylcholine is represented by the following formula (A), and more specifically, is obtained by polymerization of a monomer represented by formula (A').

In formula (A) and formula (A'), R ¹ may be either a hydrogen atom or a methyl group, and is preferably a methyl group.

The copolymer (P) used in the present invention has the structural unit (A) in its molecular chain, and is therefore capable of exerting an effect of inhibiting the adsorption of inorganic fine particles to soft contact lenses.
The content of the structural unit (A) in the copolymer (P) used in the present invention is 10 to 90 mol %. If the content is less than 10 mol %, the effect of inhibiting the adsorption of inorganic fine particles cannot be expected to be exhibited, and if it is more than 90 mol %, the adsorptivity to soft contact lenses decreases due to the superhydrophilicity of the (meth)acryloyloxyethyl phosphorylcholine segment, making it impossible to expect the effect of inhibiting the adsorption of inorganic fine particles to soft contact lenses.
The content of the structural unit (A) in the copolymer (P) is preferably from 20 to 90 mol %, and more preferably from 30 to 90 mol %.

式（Ｂ１）および式（Ｂ１’）において、Ｒ^２は水素原子もしくはメチル基のいずれでも良いが、好ましくはメチル基である。Ｒ^３は炭素数４～１８のアルキル基であり、直鎖状または分岐状のアルキル基のいずれでも良い。 <Structural Unit (B1) Based on Alkyl Group-Containing (Meth)acrylic Monomer>
The structural unit (B1) based on an alkyl group-containing (meth)acrylic monomer is represented by the following formula (B1), and more specifically, is obtained by polymerization of a monomer represented by formula (B1'): The copolymer (P) used in the present invention has the structural unit (B1) in its molecular chain, thereby enhancing the effect of suppressing the adsorption of inorganic fine particles to soft contact lenses.

In formula (B1) and formula (B1'), ^R2 may be either a hydrogen atom or a methyl group, preferably a methyl group, and ^R3 is an alkyl group having 4 to 18 carbon atoms, and may be either a linear or branched alkyl group.

Specifically, examples of linear alkyl groups having 4 to 18 carbon atoms include n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, and n-octadecyl groups. Examples of branched alkyl groups having 4 to 18 carbon atoms include t-butyl, isobutyl, isopentyl, t-pentyl, neopentyl, isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, isoundecyl, isododecyl, isotridecyl, isotetradecyl, isopentadecyl, isohexadecyl, isoheptadecyl, and isooctadecyl groups.
From the viewpoint of the effect of the copolymer (P) in suppressing the adsorption of inorganic fine particles onto a soft contact lens, an n-butyl group, an n-dodecyl group, or an n-octadecyl group is preferred.

As long as it has a structure satisfying the structural unit (B1), there is no risk of impairing the adhesiveness of the copolymer to soft contact lenses, so any can be used; however, from the viewpoint of further enhancing the adhesiveness of the copolymer to soft contact lenses, suitable examples of alkyl group-containing (meth)acrylic monomers include butyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate, with stearyl (meth)acrylate being more suitable among these.

<Structural Unit (B2) Based on Quaternary Ammonium Group-Containing (Meth)acrylic Monomer>
The structural unit (B2) based on a quaternary ammonium group-containing (meth)acrylic monomer is represented by the following formula (B2), and more specifically, is obtained by polymerization of a monomer represented by formula (B2'): The copolymer (P) used in the present invention has the structural unit (B2) in its molecular chain, thereby enhancing the effect of suppressing the adsorption of inorganic fine particles to soft contact lenses.

In formula (B2) and formula (B2'), ^R4 may be either a hydrogen atom or a methyl group, preferably a methyl group. ^R5 , ^R6 and ^R7 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and the alkyl group may be linear, branched or cyclic.

Specific examples of R ⁵ , R ⁶ , and R ⁷ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, an n-heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
R ⁵ , R ⁶ and R ⁷ are preferably a methyl group, an ethyl group, a propyl group or an isopropyl group, and more preferably a methyl group.
Examples of X ⁻ include halogen ions such as chloride ion, sulfate ion, and acid residues such as methyl sulfate ion, with halogen ions being preferred.
From the viewpoint of enhancing the effect of the copolymer in suppressing the adsorption of inorganic fine particles to soft contact lenses, a suitable example of the quaternary ammonium group-containing (meth)acrylic monomer includes 2-hydroxy-3-(meth)acryloyloxypropyltrimethylammonium chloride.

<Structural Unit (B3) Based on (Meth)acrylamide Monomer>
The structural unit (B3) based on a (meth)acrylamide monomer is represented by the following formula (B3), and more specifically, is obtained by polymerization of a monomer represented by formula (B3'): By having the structural unit (B3) in the molecular chain, the copolymer (P) used in the present invention can have a high molecular weight and further enhance the effect of the copolymer in suppressing the adsorption of inorganic fine particles to soft contact lenses.

In formula (B3) and formula (B3'), R ⁸ may be either a hydrogen atom or a methyl group, but is preferably a hydrogen atom. ^{R 9} and R ¹⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and the alkyl group may be any of linear, branched, and cyclic. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. R ⁹ and R ¹⁰ are preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, or an isopropyl group, and more preferably a methyl group.
From the viewpoint of increasing the molecular weight of the copolymer and further enhancing the effect of the copolymer in inhibiting adsorption of inorganic fine particles to soft contact lenses, a suitable example of the (meth)acrylamide monomer includes N,N-dimethylacrylamide.

The copolymer (P) used in the present invention has at least one structural unit selected from the group consisting of (B1), (B2) and (B3) in the molecular chain. The copolymer used in the present invention may have only one structural unit selected from the group consisting of (B1), (B2) and (B3) in the molecular chain, may have two structural units selected from the group consisting of (B1), (B2) and (B3) (for example, a combination of (B1) and (B2), a combination of (B2) and (B3), a combination of (B3) and (B1)), or may have all structural units of (B1), (B2) and (B3).

The copolymer (P) used in the present invention has not only the structural units (B1) to (B3) but also the structural unit (A) in the same polymer chain, and therefore the copolymer (P) used in the present invention becomes an inorganic fine particle adsorption inhibitor for soft contact lenses that exhibits the effect of inhibiting the adsorption of inorganic fine particles to soft contact lenses.

The content of the structural units (B1) to (B3) in the copolymer (P) used in the present invention (the content of the structural unit when only one of (B1) to (B3) is contained, and the total content of these structural units when two or three of (B1) to (B3) are contained) is 10 to 90 mol%, preferably 10 to 80 mol%, and more preferably 10 to 70 mol%. If the content is less than 10 mol%, the hydrophilicity of the copolymer becomes high, and the adsorptivity or adhesion to soft contact lenses becomes poor, and there is a risk that the inorganic fine particle adsorption inhibitor effect will not be achieved. If the content is more than 90 mol%, the solubility in water decreases, and it may be difficult to produce an inorganic fine particle adsorption inhibitor for soft contact lenses.

Suitable examples of combinations of the structural unit (A) and the structural units (B1) to (B3) contained in the molecular chain of the copolymer (P) used in the present invention, from the viewpoint of expressing the effect of inhibiting the adsorption of inorganic fine particles onto soft contact lenses, include the following combinations.

2-(meth)acryloyloxyethyl phosphorylcholine and butyl (meth)acrylate;
2-(meth)acryloyloxyethyl phosphorylcholine and stearyl (meth)acrylate;
2-(meth)acryloyloxyethyl phosphorylcholine and 2-hydroxy-3-(meth)acryloyloxypropyltrimethylammonium chloride;
And,
2-(meth)acryloyloxyethyl phosphorylcholine, N,N-dimethylacrylamide and stearyl (meth)acrylate.

The copolymer used in the present invention may contain structural units other than the structural unit (A) and the structural units (B1) to (B3), but preferably consists of the structural unit (A) and one, two or three structural units selected from the group consisting of the structural units (B1), (B2) and (B3). Among these, combinations of (A) and (B1), combinations of (A) and (B2), and combinations of (A), (B1) and (B3) are preferred, and combinations of (A) and (B1), and combinations of (A), (B1) and (B3) are more preferred, with the combination of (A) and (B1) being even more preferred.

The weight-average molecular weight of the copolymer used in the present invention is 10,000 to 5,000,000, and preferably 20,000 to 2,000,000. If the weight-average molecular weight is less than 10,000, the adsorptivity or adhesion to soft contact lenses decreases, and the effect of inhibiting the adsorption of inorganic fine particles cannot be expected, whereas if the weight-average molecular weight is more than 5,000,000, the viscosity increases rapidly, making it difficult to produce an inorganic fine particle adsorption inhibitor for soft contact lenses.

The weight average molecular weight of the copolymer (P) is determined by GPC (gel permeation chromatography) measurement in terms of polyethylene glycol.
The copolymer (P) of the present invention may be one having a specific weight average molecular weight, or may be a mixture of two or more having different weight average molecular weights. By using a mixture of two or more having different weight average molecular weights, the copolymer (P) has an improved effect of suppressing the adsorption of inorganic fine particles to soft contact lenses.

When two types are used in combination, a combination of copolymer (P1) having a weight average molecular weight of 200,000 to 800,000 and copolymer (P2) having a weight average molecular weight of 900,000 to 1,500,000, or a combination of copolymer (P1') having a weight average molecular weight of 250,000 to 800,000 and copolymer (P3) having a weight average molecular weight of 10,000 to 200,000 is preferred.
The blending ratio of the copolymer (P1) to the copolymer (P2) is 1:9 to 9:1, preferably 3:7 to 7:3, and more preferably 4:6 to 6:4, by weight.
The blending ratio of the copolymer (P1') to the copolymer (P3) is 1:9 to 9:1, preferably 3:7 to 7:3, and more preferably 4:6 to 6:4, by weight.

The inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention preferably contains 0.001 to 5.0 w/v % copolymer (P) and water as a solvent. A mixed solvent of water and alcohol may also be used as the solvent. Examples of the alcohol include methanol, ethanol, n-propanol, and isopropanol. In this case, the inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention can be obtained by dissolving the copolymer (P) in water or the above mixed solvent to a concentration of 0.001 to 5.0 w/v %. If the concentration of the copolymer (P) is less than 0.001 w/v %, a sufficient inorganic fine particle adsorption inhibitory effect cannot be obtained, and even if the concentration of the copolymer (P) exceeds 5.0 w/v %, there is a risk that an inorganic fine particle adsorption inhibitory effect commensurate with the blending amount cannot be obtained.
The concentration of the copolymer (P) is preferably 0.01 to 5.0 w/v %, more preferably 0.01 to 4.0 w/v %, and even more preferably 0.01 to 3.0 w/v %.

The water used in the present invention may be any water as long as it is for use in the production of pharmaceuticals or has a quality equivalent thereto. For example, water described in the Japanese Pharmacopoeia may be used.
By using the copolymer (P) of the present invention in a soft contact lens, adsorption of inorganic fine particles during wearing of the soft contact lens can be suppressed, and allergic conjunctivitis can be alleviated or reduced, thereby providing an effect of improving discomfort during wearing of the soft contact lens.

The inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention can exhibit an adsorption inhibitory effect against inorganic fine particles (such as PM10 (fine particles having a particle diameter of approximately 10 μm or less that pass through a particle size classification device with a collection efficiency of 50% at a particle diameter of 10 μm).
Specifically, it is effective against inorganic fine particles such as fine particulate matter (PM10 [fine particles with a particle diameter of approximately 10 μm or less that pass through a classification device with a particle diameter of 10 μm and a collection efficiency of 50%.], PM5 [fine particles with a particle diameter of approximately 5 μm or less that pass through a classification device with a particle diameter of 5 μm and a collection efficiency of 50%.], PM2.5 [fine particles with a particle diameter of approximately 2.5 μm or less that pass through a classification device with a particle diameter of 2.5 μm and a collection efficiency of 50%.]), yellow sand, and falling dust.

In addition to the copolymer (P) and water, the inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention can contain, as necessary, congestion relief ingredients, anti-inflammatory and astringent ingredients, vitamins, amino acids, sulfa drugs, sugars, cooling agents, inorganic salts, salts of organic acids, acids, bases, antioxidants, stabilizers, preservatives, mucin secretion promoters, and the like that can generally be used in ophthalmic preparations.

Examples of congestion relief ingredients include epinephrine or its salts, ephedrine hydrochloride, tetrahydrozoline hydrochloride, naphazoline or its salts, phenylephrine, and methylephedrine hydrochloride.

Examples of anti-inflammatory and astringent ingredients include epsilon-aminocaproic acid, allantoin, berberine or its salt, sodium azulene sulfonate, glycyrrhizinic acid or its salt, zinc lactate, zinc sulfate, and lysozyme chloride.

Examples of vitamins include flavin adenine dinucleotide sodium, cyanocobalamin, retinol acetate, retinol palmitate, pyridoxine hydrochloride, panthenol, sodium pantothenate, and calcium pantothenate.

Examples of amino acids include aspartic acid or its salts, and aminoethylsulfonic acid.

Examples of sulfa drugs include sulfamexazole or its salts, sulfisoxazole, and sulfisomidine sodium.

Examples of sugars include glucose, mannitol, sorbitol, xylitol, and trehalose.
Examples of the cooling agents include menthol and camphor.

Examples of inorganic salts include sodium chloride, potassium chloride, borax, sodium bicarbonate, sodium hydrogen phosphate, and anhydrous sodium dihydrogen phosphate.

An example of a salt of an organic acid is sodium citrate.
Examples of the acid include boric acid, phosphoric acid, citric acid, sulfuric acid, acetic acid, and hydrochloric acid.
Examples of the base include sodium hydroxide, potassium hydroxide, trishydroxymethylaminomethane, and monoethanolamine.

Examples of the antioxidant include tocopherol acetate and dibutylhydroxytoluene.
Stabilizers include, for example, sodium edetate and glycine.
Examples of preservatives include benzalkonium chloride, chlorhexidine gluconate, potassium sorbate, methylparaben, ethylparaben, propylparaben, isopropylparaben, butylparaben, isobutylparaben, and polyhexanide hydrochloride.
Examples of mucin secretion promoters include diquafosol sodium and rebamipide.

Specific product forms containing the inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention are not particularly limited as long as they are ophthalmic preparations, but examples include the following: Eye drops, contact lens wetting solution, contact lens cleaning solution, contact lens cleaning and storage solution, contact lens filling solution, and other soft contact lens care products.

From the viewpoint of enhancing the inorganic fine particle adsorption inhibitory effect, the inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention is preferably applied to soft contact lenses of Group III and Group IV in the FDA classification (ionic soft contact lenses). The FDA classification is a classification of soft contact lenses stipulated by the U.S. Food and Drug Administration (FDA), and is stipulated as follows: Group I: non-ionic soft contact lenses with a water content of less than 50%, Group II: non-ionic soft contact lenses with a water content of 50% or more, Group III: ionic soft contact lenses with a water content of less than 50%, and Group IV: ionic soft contact lenses with a water content of 50% or more.

Specific examples of soft contact lenses classified as Group III or Group IV include the following. (The numbers in parentheses indicate the water content, followed by the main components that make up the soft contact lens.)

(Group III Soft Contact Lenses)
balafilcon A (36%, Tris-VC, NVP)

(Group IV soft contact lenses)
etafilcon A (58%, 2-hydroxyethyl methacrylate, methacrylic acid), ocufilcon B (52%, 2-hydroxyethyl methacrylate, methacrylic acid), ocufilcon D (55%, 2-hydroxyethyl methacrylate, methacrylic acid), phemefilcon A (55%, 2-hydroxyethyl methacrylate, ethoxyethyl methacrylate, methacrylic acid), vifilcon A (55%, 2-hydroxyethyl methacrylate, polyvinylpyrrolidone, methacrylic acid), methafilcon A (55%, 2-hydroxyethyl methacrylate, methacrylic acid), bufilcon A (55%, 2-hydroxyethyl methacrylate, diacetoneacrylamide, methacrylic acid), perfilcon A (71%, 2-hydroxyethyl methacrylate, N-vinylpyrrolidone, methacrylic acid), SEED 1DAY PURE Moisture Plus (58%, 2-hydroxyethyl methacrylate, quaternary ammonium group-containing methacrylate compound, carboxyl group-containing methacrylate compound, methacrylic acid, ethylene glycol dimethacrylate)

Among these, from the viewpoint of inhibiting the adsorption of inorganic microparticles onto soft contact lenses, Group IV soft contact lenses are preferred, and more preferred are Group IV soft contact lenses with a water content of 55% or more.

The inorganic fine particle adsorption inhibitor for soft contact lenses of the present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited thereto. The copolymers used in the examples and comparative examples are as follows:

Copolymer (P1): 2-methacryloyloxyethyl phosphorylcholine/butyl methacrylate copolymer [structural unit (A) 80 mol %, structural unit (B1) 20 mol %, weight average molecular weight: 600,000].
Copolymer (P2): 2-methacryloyloxyethyl phosphorylcholine/butyl methacrylate copolymer [structural unit (A) 80 mol %, structural unit (B1) 20 mol %, weight average molecular weight: 1,100,000].
Copolymer (P3): 2-methacryloyloxyethyl phosphorylcholine/butyl methacrylate copolymer [structural unit (A) 80 mol %, structural unit (B1) 20 mol %, weight average molecular weight: 150,000].
Copolymer (P4): 2-methacryloyloxyethyl phosphorylcholine/butyl methacrylate copolymer [structural unit (A) 30 mol %, structural unit (B1) 70 mol %, weight average molecular weight: 142,000].
Copolymer (P5): 2-methacryloyloxyethyl phosphorylcholine/stearyl methacrylate copolymer [structural unit (A) 80 mol %, structural unit (B1) 20 mol %, weight average molecular weight: 60,000].
Copolymer (P6): 2-methacryloyloxyethyl phosphorylcholine.2-hydroxy-3-methacryloyloxypropyltrimethylammonium copolymer [70 mol % of structural unit (A), 30 mol % of structural unit (B2), weight average molecular weight: 450,000].
Copolymer (P7): 2-methacryloyloxyethyl phosphorylcholine · N,N-dimethylacrylamide · stearyl methacrylate copolymer [structural unit (A) 50 mol %, structural unit (B3) 45 mol %, structural unit (B1) 5 mol %, weight average molecular weight: 200,000].

Comparative Polymer (Q1): A polymer of butyl methacrylate (weight average molecular weight: 180,000), purchased from Fujifilm Wako Pure Chemical Industries, Ltd. (product name: poly(n-butyl methacrylate)).
Comparative polymer (Q2): A polymer of 2-hydroxy-3-methacryloyloxypropyltrimethylammonium (weight average molecular weight: 300,000), obtained by polymerization according to the method described in the examples of JP-A-8-258403.
Comparative Example Polymer (Q3): A polymer of N,N-dimethylacrylamide [number average molecular weight: 10,000], purchased from Sigma-Aldrich Japan (product name: Poly(N,N-dimethylacrylamido), DDMAT terminated) and used in the test.

The weight average molecular weight of each of the copolymers described above was measured by gel permeation chromatography (GPC) under the following conditions.
GPC system: High performance liquid chromatography system CCP&8020 series (manufactured by Tosoh Corporation)
Column: Shodex OHpak SB-802.5HQ (Showa Denko K.K.) and SB-806HQ (Showa Denko K.K.) connected in series. Developing solvent: 20 mM sodium phosphate buffer (pH 7.4)
Detector: Differential refractive index detector, UV detector (wavelength 210 nm)
Molecular weight standard: EasiVial PEG/PEO (Agilent Technologies)
Flow rate: 0.5 mL/min Column temperature: 45° C.
Sample: The obtained copolymer was diluted with the developing solvent to a final concentration of 0.1% by weight.

<Phosphate buffer solution>
In the following inorganic fine particle adsorption test, phosphate buffer solution (hereinafter referred to as "PBS") was used. PBS (composition: potassium chloride 0.02 w/v%, potassium dihydrogen phosphate 0.02 w/v%, sodium chloride 0.8 w/v%, disodium hydrogen phosphate 0.115 w/v%) manufactured by Sigma-Aldrich was used.

<Inorganic particle adsorption test>
A test for inorganic fine particle adsorption onto soft contact lenses was carried out according to the following procedure.
(1) One soft contact lens was removed from the blister pack and washed with PBS. The washed soft contact lens was placed in a 24-well plate, and 2 mL of the solution of each Example or Comparative Example was added.
(2) After this, the mixture was shaken for 1 hour.
(3) Using urban air dust (PM2.5, manufactured by the National Institute for Environmental Studies), PBS and an ultrasonic homogenizer (treatment with homogenizer: 1 minute), an urban air dust solution was prepared so that the urban air dust concentration was 1 mg/mL (hereinafter referred to as the "air dust solution").
(4) A new 24-well plate was prepared, and 1.5 mL of the atmospheric dust solution was added thereto. Furthermore, the soft contact lens prepared in (2) was immersed in the plate for 1 hour.
(5) After immersion, the soft contact lens was taken out and washed three times with 10 mL of PBS.
(6) After cleaning, the transmittance of the soft contact lens was measured, and the amount of atmospheric dust particles adsorbed on the surface of the soft contact lens (amount of inorganic fine particles adsorbed) was measured.

In the inorganic fine particle adsorption test, the inorganic fine particle adsorption suppression effect was judged according to the following criteria.
Using Comparative Examples 1-4, 3-1 and 3-2 as standards, the inorganic fine particle adsorption suppression rate was calculated using the following formula to judge whether or not there was an effect of suppressing the adsorption of inorganic fine particles.
(Inorganic fine particle adsorption inhibition rate)={1-((Inorganic fine particle adsorption amount of each Example or Comparative Example)/(Inorganic fine particle adsorption amount of each Comparative Example using the corresponding soft contact lens/fine particle type))}×100

(Criteria for judgment)
Inorganic particle adsorption inhibition rate of 70% or more: The inorganic particle adsorption inhibition effect is extremely excellent. Inorganic particle adsorption inhibition rate of 50% or more and less than 70%: The inorganic particle adsorption inhibition effect is excellent. Inorganic particle adsorption inhibition rate of 30% or more and less than 50%: The inorganic particle adsorption inhibition effect is achieved. Inorganic particle adsorption inhibition rate of less than 30%: The inorganic particle adsorption inhibition effect is not achieved.

[Example 1-1]
Approximately 80 g of purified water was weighed out, 1.0 g of copolymer (P1) was weighed out and added thereto, and the mixture was stirred. After that, purified water was added so that the total amount became 100 mL. Further, the mixture was subjected to sterile filtration to obtain a solution of Example 1-1. The properties of the solution are shown in Table 1.

[Examples 1-2 to 1-9, Comparative Examples 1-1 to 1-4]
Using the components and amounts shown in Table 1, solutions of Examples 1-2 to 1-9 and Comparative Examples 1-1 to 1-4 were prepared in the same manner as in Example 1-1.

[Example 2-1]
The above-mentioned inorganic fine particle adsorption test was carried out using the solution of Example 1-1 and Seed 1day Pure Moisture Plus (a soft contact lens manufactured by Seed). The results are shown in Table 2.

[Examples 2-2 to 2-9, Comparative Examples 2-1 to 2-4]
An inorganic fine particle adsorption test was carried out using the solutions of the Examples or Comparative Examples and soft contact lenses shown in Table 2. The inorganic fine particle adsorption test was carried out in the same manner as in Example 2-1. The inorganic fine particle adsorption test results for Examples 2-2 to 2-9 and Comparative Examples 2-1 to 2-4 are shown in Table 2.

[Example 3-1]
The inorganic fine particle adsorption test was carried out in the same manner as in Example 2-1, except that the solution of Example 1-5 was used and the soft contact lens was changed to Bausch & Lomb Medalist Fresh Fit (soft contact lens manufactured by Bausch & Lomb Japan). The results are shown in Table 3.

[Examples 3-2 to 3-6, Comparative Examples 3-1 to 3-2]
An inorganic fine particle adsorption test was carried out using the solutions, soft contact lenses, and fine particle species of the examples shown in Table 3. The inorganic fine particle adsorption test was carried out in the same manner as in Example 3-1. The results of the inorganic fine particle adsorption test for Examples 3-2 to 3-6 and Comparative Examples 3-1 and 3-2 are shown in Table 3.

水：日本薬局方 精製水、健栄製薬製
＊：不溶であったため、調製不可

Water: Purified water according to the Japanese Pharmacopoeia, manufactured by Kenei Pharmaceutical Co., Ltd. *: Cannot be prepared as it was insoluble

レンズ（１）：シードワンデーピュアうるおいプラス：シード製、度数：－３．００Ｄ、ベースカーブ：８．８、直径：１４．２、含水率：５８％、構成モノマー：２－ＨＥＭＡ・４級アンモニウム基含有メタクリレート・カルボキシル基含有メタクリレート・ＭＡＡ・ＥＧＤＭＡ、ＦＤＡ分類：グループＩＶ（イオン性ソフトコンタクトレンズ）

Lens (1): Seed One Day Pure Moisture Plus: Made by Seed, Diopter: -3.00D, Base Curve: 8.8, Diameter: 14.2, Water Content: 58%, Constituent Monomers: 2-HEMA, Quaternary Ammonium Group-containing Methacrylate, Carboxyl Group-containing Methacrylate, MAA, EGDMA, FDA Classification: Group IV (Ionic Soft Contact Lenses)

The results of Examples 2-1 to 2-9 and Comparative Examples 2-1 to 2-4 show that the incorporation of copolymer (P) suppresses the adsorption of inorganic fine particles (urban air dust) to soft contact lenses. Furthermore, the effect of suppressing the adsorption of inorganic fine particles improves depending on the concentration of copolymer (P). Furthermore, the results of Examples 2-4 to 2-9 show that the effect of suppressing the adsorption of inorganic fine particles is expressed even when the type and formulation of copolymer (P) is changed.

レンズ（２）：ボシュロムメダリストフレッシュフィット：ボシュロム・ジャパン製、度数：－３．００Ｄ、ベースカーブ：８．６、直径：１４．０、含水率：３６％、構成モノマー：ＴｒｉｓＶＣ・ＮＶＰ、ＦＤＡ分類：グループＩＩＩ（イオン性ソフトコンタクトレンズ）
黄砂：ゴビ黄砂（国立環境研究所製）を用いた。

Lens (2): Bausch & Lomb Medalist Fresh Fit: Made by Bausch & Lomb Japan, Diopter: -3.00D, Base Curve: 8.6, Diameter: 14.0, Water Content: 36%, Constituent Monomer: TrisVC/NVP, FDA Classification: Group III (ionic soft contact lens)
Yellow sand: Gobi yellow sand (manufactured by the National Institute for Environmental Studies) was used.

The results of Examples 3-1 to 3-6 demonstrated that the inhibitory effect of copolymer (P) on the adsorption of inorganic fine particles is not limited to urban air dust, but also exerts a similar effect on other air pollutants such as yellow sand.

By using the inorganic microparticle adsorption inhibitor for soft contact lenses of the present invention, it is possible to produce soft contact lens care products that inhibit the adsorption of inorganic microparticles to contact lenses, thereby alleviating and reducing the symptoms of allergic conjunctivitis and improving discomfort.

Claims (1)

A soft contact lens adsorption inhibitor for urban air particulate matter (PM2.5) and yellow sand, comprising a copolymer (P) having a weight average molecular weight of 10,000 to 5,000,000 and containing 10 to 90 mol % of a structural unit (A) based on 2-(meth)acryloyloxyethyl phosphorylcholine and 90 to 10 mol % of at least one structural unit selected from the group consisting of a structural unit (B1) based on an alkyl group-containing (meth)acrylic monomer, a structural unit (B2 ) based on a quaternary ammonium group-containing (meth)acrylic monomer, and a structural unit (B3) based on a (meth)acrylamide monomer.
(In formula (A), R ¹ represents a hydrogen atom or a methyl group. In formula (B1), R ² represents a hydrogen atom or a methyl group, and R ³ represents an alkyl group having 4 to 18 carbon atoms. In formula (B2), R ⁴ represents a hydrogen atom or a methyl group, R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and X ⁻ represents a halogen ion or an acid residue. In formula (B3), R ⁸ represents a hydrogen atom or a methyl group, and R ⁹ and R ¹⁰ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)