JPS6251447B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a contact lens and a method for manufacturing the same, and the present invention relates to a contact lens whose main component is a collagen-hydroxyalkyl methacrylate copolymer (however, the collagen in this copolymer is about 0.007 to 1.3% by weight based on the hydroxyalkyl methacrylate). By using it as a lens material, it has good properties such as oxygen permeability and water wettability, has excellent wearing comfort and biocompatibility, has excellent tensile strength and is difficult to break, is easy to handle, and has excellent processability. It is an object of the present invention to provide a contact lens that can be easily manufactured at low cost since it is an excellent material, and a method for manufacturing the same. Traditionally, polymethyl methacrylate (hereinafter abbreviated as PMMA), for example, has been mainly used as a material for contact lenses.
PMMA has poor hydrophilicity, so it is difficult to wet with water, which makes it uncomfortable to wear, and furthermore, it has low oxygen permeability, so wearing it for long periods of time can cause physiological problems such as corneal swelling. There is. Therefore, as a material to replace PMMA, for example, 2-hydroxyethyl methacrylate (hereinafter referred to as 2-
Gel-like soft contact lenses with water-containing properties have been developed and put into practical use, with materials such as HEMA (abbreviated as HEMA) or N-vinyl-2-pyrrolidone (abbreviated as NVP hereinafter) as the main ingredients. -Soft contact lenses made from HEMA and NVP are said to be superior to hard contact lenses made from PMMA in terms of comfort, and are also more permeable to oxygen and inorganic ions. However, it has been pointed out that contact lenses made of such materials have drawbacks such as poor biocompatibility because cell proliferation is inhibited and they are anticoagulant. Therefore, from this perspective, a gel contact lens containing collagen as the main component has been proposed (Japanese Patent Application Laid-Open No. 53-78854 = Japanese Patent Publication No. 55-5089).
It is stated that contact lenses whose main component is collagen have excellent oxygen permeability and excellent compatibility with the cornea. 99%, the refractive index of this contact lens is almost the same as that of water, and although it can be used to correct extremely weak vision, it is When correcting visual acuity for severe or severe refractive errors, contact lenses must be made extremely thick, and as a result, they tend to fall out of the wearer's eyes, and they also have a strong foreign body sensation. The drawback is that the feeling of wearing it is extremely poor. In addition, contact lenses whose main ingredient is collagen are prone to the growth of mold and bacteria, which makes them difficult to handle, and if you try to sterilize them by boiling, etc., they lack heat resistance, so they cannot last long. Conventional contact lenses containing collagen as a main component have not yet been put into practical use.
Furthermore, contact lenses whose main component is collagen are extremely weak in terms of strength and are easily damaged, resulting in almost no durability. In addition, materials whose main component is collagen have extremely poor workability, making it extremely difficult to manufacture contact lenses capable of correcting normal vision, and also having disadvantages such as high cost. By the same inventor as the inventor of the contact lens proposed above (Japanese Patent Application Laid-Open No. 53-78854), the contact lens not only contains collagen as the main ingredient, but also contains a small amount of water-soluble organic polymer incidentally to collagen. A contact lens was proposed in which a molecular compound was used, that is, 1.0 to 30% by weight of collagen, 0.1 to 30% by weight of a water-soluble organic polymer compound, and the balance was water (Japanese Patent Application Laid-Open No. 11430/1983). ) However, even with this newly proposed contact lens, since its basis is mainly collagen, it is not possible to use collagen as the main ingredient proposed in the above-mentioned Japanese Patent Application Laid-Open No. 53-78854. The same drawbacks as those for contact lenses are expected. The present invention eliminates the above-mentioned drawbacks, and examples thereof will be described below. Example 1 Approximately 3 g of 2-HEMA, as collagen, for example, a 0.5% solution (in 0.1 M acetic acid) of Nitsupi Collagen SCE (Enzyme Solubilized Collagen) from Nitsupi Co., Ltd.
g. As a crosslinking agent, for example, about 0.1 g of glycidyl methacrylate (GMA) and about 0.01 g of ethylene glycol dimethacrylate (EDMA) are thoroughly mixed, and the mixture is left under reduced pressure to sufficiently defoam and remove dissolved oxygen. After that, add about 0.002g of V65 as a polymerization initiator, such as azobis-based polymerization initiator.
Add the solution dissolved in about 0.1g of 2-HEMA,
Stir thoroughly in a desiccator that has been purged with nitrogen. Thereafter, this mixed solution is injected into a contact lens molding container, and a conventional polymerization process is performed to form a collagen and hydroxyalkyl methacrylate copolymer. After this polymerization process, the polymer is taken out from the molding container and A contact lens made of 2-HEMA-collagen copolymer is obtained by copolymerizing collagen at a ratio of about 0.007 to 1.3% by weight. This contact lens was flexible and had a water content of 42%. Example 2 2-HEMA approximately 4.7 parts by weight, Nitsupi Collagen
Approximately 0.3 parts by weight of a 1% solution of SCE (in 0.1M acetic acid),
After thoroughly mixing about 0.1 part by weight of GMA and about 0.02 part by weight of EDMA and defoaming, azobis-based polymerization initiator V
-65 or 6% (NH ₄ ) ₂ S ₂ O ₄ and 12%
A predetermined amount of a polymerization initiator such as Na ₂ S ₂ O ₅ is added, and this is placed in a predetermined glass tube and subjected to a predetermined polymerization treatment, so that collagen is approximately 0.007% of 2-HEMA.
2- formed by copolymerization at a ratio of ~1.3% by weight
A rod-shaped block made of HEMA-collagen copolymer is obtained. Thereafter, this rod-shaped block is subjected to a conventional contact lens molding process, and is made of 2-HEMA-collagen copolymer, in which collagen is copolymerized with 2-HEMA at a ratio of about 0.007 to 1.3% by weight. Get contact lenses. Example 3 Approximately 3 g of 2-HEMA, approximately 2 g of a 2% solution (in 0.1 acetic acid) of Nitsupi Collagen SCE (made by Nitsupi Co., Ltd.) as collagen, and approximately 0.1 g of GMA were thoroughly mixed, and this mixture was heated under reduced pressure. After leaving to stand for sufficient degassing to remove dissolved oxygen, add a solution of about 0.002 g of azobis-based polymerization initiator V-65 in about 0.1 g of 2-HEMA, and stir thoroughly in a desiccator that has been purged with nitrogen in advance. Stir. Then, this stirred mixed solution is poured into a contact lens molding container made of quartz, polymerization treatment is carried out in a conventional manner, and after the polymerization treatment, the polymerized product is taken out from the molding container. Then, 2-HEMA is copolymerized with collagen at a ratio of about 0.007 to 1.3% by weight.
- HEMA - A contact lens made of collagen copolymer is obtained. Contact lenses obtained as above and conventional contact lenses, such as Japanese Patent Publication No. 55-5089
Gel-like contact lenses based on collagen proposed in No. 1 (Comparative Example 1), contact lenses based on 2-HEMA (Comparative Example 2), and the proposal in JP-A-56-11430 (Example 7) As in, collagen-2-HEMA (collagen is 2
The various properties of the contact lens (Comparative Example 3) made of (approximately 80% by weight based on HEMA) were measured and were as shown in the table.

[Table] According to the results, the contact lenses according to the present invention can be improved by containing a small amount of collagen.
Although the water content is higher than HEMA gel alone, it is not as high as collagen gel.
Therefore, the refractive index is not much different from that of HEMA gel alone, and it has a sufficient refractive index for a contact lens.Therefore, for moderate to strong refractive abnormalities, the thickness of the contact lens can be increased accordingly. There is no need to wear it, and the feeling of wearing it is excellent. or,
Collagen gel is fragile, so there is a high risk of damaging the contact lens when putting it on and taking it off, whereas the contact lens of the present invention has a higher tensile strength than collagen gel or HEMA gel alone, so there is no risk of breakage. . In addition, collagen gel contact lenses, which contain 97% water, are quite heavy and have the disadvantage that the center of the contact lenses tends to shift when wearing them. The contact lens of the invention has no such drawbacks and is good. In addition, collagen gel contact lenses are
Collagen itself is highly fertile for bacteria and mold, so bacteria and mold often grow there.However, the contact lenses of the present invention contain only a small amount of collagen, so bacteria and mold do not grow. There is almost no difference from HEMA gel contact lenses, and even if bacteria or mold develops,
It can be easily removed by the same treatment as for HEMA-only contact lenses, such as boiling sterilization.
In addition, contact lenses are not damaged in this process. On the other hand, collagen gel contact lenses have poor heat resistance, so it is difficult to treat the growth of bacteria and mold. In addition, the contact lens according to the present invention is stable in terms of base curve, power, and size like a contact lens with only HEMA, whereas the collagen gel contact lens is not stable in these characteristics and cannot be used as a contact lens. It is not suitable for vision correction. Furthermore, the contact lens according to the present invention includes:
Collagen gel contact lenses and
It is superior to a contact lens containing only HEMA, and its affinity with the corneal tissue is far superior to that of a contact lens containing only HEMA. In addition, even though it contains only a small amount of collagen, its oxygen permeability is much higher than that of HEMA alone, so it has sufficient oxygen permeability as a contact lens and can be worn continuously for a long period of time. . In addition, since the contact lens according to the present invention has a certain degree of hardness, it can move sufficiently on the cornea even when the contact lens is worn, and the feeling of wearing is excellent. It can be easily made by various methods such as the so-called lace cut method, molding method or spin cast method,
It can be made at low cost. Incidentally, even if a copolymer of collagen and poly2-hydroxyethyl methacrylate as proposed in JP-A-56-11430 can be used as a contact lens material, the When the amount of collagen is relatively large, its properties are basically the same as in the case of JP-A-53-78854, which mainly consists of collagen, and the excellent effects as in the case of the present invention cannot be obtained. do not have. For example, when making a copolymer of 2-HEMA monomer and collagen, 2-
Dry collagen does not dissolve in HEMA monomers at all, so an acidic solution of collagen in acetic acid, for example, must be used.Moreover, collagen solutions have a very high viscosity and cannot be used in copolymers with, for example, 2-HEMA. The upper limit of the collagen solution was about 2%. In addition, 2-HEMA can be polymerized even in a water-containing state, but when the proportion of water is about 50
When the amount exceeded % by weight, the HEMA polymer matrix could no longer maintain its normal shape and became gel-like, but with no transparency at all.
Therefore, in order to carry out polymerization in a hydrated state, water must be about 50%
It is necessary that the amount is not more than 40% by weight, preferably not more than about 40% by weight from the viewpoint of transparency as a lens.
From these facts, in order to make a HEMA-collagen copolymer that can be used as a contact lens, the collagen concentration should be approximately 0.8% by weight or less based on the total water-containing copolymer, and the 2-HEMA
It had to be less than about 1.3% by weight. In addition, HEMA-collagen copolymer requires a certain amount in order to have good properties as a contact lens because it contains collagen.For example, for the entire copolymer containing water, The collagen concentration is about 0.004% by weight or more, and the collagen concentration is about 0.004% by weight or more for 2-HEMA.
It was desirable that the content be 0.007% by weight or more.
Also, as a contact lens, the water content is 50% by weight.
If it exceeds this level, it becomes opaque and has poor optical properties, making it unusable as a lens. In the above example, 2-HEMA was explained as a substance copolymerizable with collagen, but substances with a similar structure to 2-HEMA, such as

[Formula] (However, R is

[Formula] or

The same was true for hydroxyalkyl methacrylates such as [Formula], etc. On the other hand, attempts were made to create a copolymer with collagen by using methyl methacrylate instead of 2-HEMA, but methyl methacrylate hardly mixes with water and dried collagen dissolves in methyl methacrylate. Therefore, it was not possible to create a copolymer of methyl methacrylate and collagen. Also, using NVP, which is well known as a soft contact lens material, a copolymer of NVP and collagen was prepared in the same manner as in the above example, and a contact lens was made from this copolymer. In the case of NVP, it is completely different from the case of 2-HEMA; when NVP alone is polymerized with collagen, it is extremely brittle, and a material with such characteristics cannot be used as a contact lens at all. Ta. In addition, in the case of using not only NVP but also a mixture of 2-HEMA and NVP, and a copolymer with collagen mainly composed of 2-HEMA, it is possible to The shortcomings had been improved. As described above, the contact lens according to the present invention is constructed using a collagen-hydroxyalkyl methacrylate copolymer in which the ratio of collagen to hydroxyalkyl methacrylate is approximately 0.007 to 1.3% by weight, and the water content of the copolymer is The rate is approx.
Since it has a content of 40% by weight or less, it has excellent optical properties, tensile strength, and oxygen permeability coefficient, and is relatively thin for vision correction, especially for people with severe refractive abnormalities. Therefore, even when worn on the eye, there is little sensation of a foreign body, the feeling of wearing is excellent, it is easy to handle when worn, and it is difficult for bacteria and mold to grow, even if these things do occur. They can be removed using the same procedure as conventional soft contact lenses, and they have excellent tensile strength, making them less likely to break. Furthermore, they have excellent compatibility with lachrymal fluid and corneal tissue, so they feel as comfortable to wear as conventional soft contact lenses. It is far superior to collagen-only gel contact lenses, etc., and has a high oxygen permeability coefficient, so it can be worn continuously for a long time, and the contact lenses are also easy to process. The contact lens manufacturing method according to the present invention can be easily manufactured at low cost using the conventional lace cut method, molding method, spin cast method, etc., and the collagen content is about 0.007 to 1.3% by weight based on the hydroxyalkyl methacrylate. Contact lenses are made by polymerizing a mixture of hydroxyalkyl methacrylate, collagen, and water so that the water content is approximately 40% by weight or less. It has the advantage of being easy to make as a polymer, making it possible to make contact lenses that are highly durable and comfortable to wear at low cost.

Claims (1)

[Scope of Claims] 1. Constructed using a collagen-hydroxyalkyl methacrylate copolymer in which collagen is about 0.007 to 1.3% by weight based on hydroxyalkyl methacrylate, and the water content of the copolymer is about 0.007 to 1.3% by weight.
A contact lens characterized in that the content is 40% by weight or less. 2. Polymerization treatment of a mixture of hydroxyalkyl methacrylate, collagen, and water such that collagen is about 0.007 to 1.3% by weight based on hydroxyalkyl methacrylate, and water content is about 40% by weight or less. A method for manufacturing contact lenses characterized by subjecting them to.