JPH03249727A - Aqueous solution for contact lens - Google Patents

Abstract

PURPOSE:To obtain the aq. soln. which prevents the change in the shape of a contact lens at the time of rinsing or preserving and is safe and is easily usable by confining the concn. of the sodium chloride in the aq. soln. to <=0.8w/v%, incorporating an osmotic pressure control agent therein in such a manner that the osmotic pressure is substantially equal to the osmotic pressure of tears and further subjecting this aq. soln. to radiation sterilization. CONSTITUTION:The concn. of the sodium chloride in the aq. soln. is confined to <=0.8w/v%. Further, the content of the osmotic pressure control agent to be incorporated in addition to the sodium chloride into the aq. soln. is so determined that the osmotic pressure of the aq. soln. is substantially equal to he osmotic pressure of the tears. This aq. soln. is subjected to the radiation sterilization. The radiations used in the radiation sterilization include alpha rays, beta rays, gammarays, X rays and electron rays. The change in the shape of the soft contact lens is obviated even if this aq. soln. is used for preserving or rinsing the lens. In addition, the aq. soln. is highly safe to the eyes and is easily usable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an aqueous solution for contact lenses, and particularly an aqueous solution for contact lenses that does not cause any change in the shape of contact lenses even when the contact lenses are rinsed or stored. Regarding.

[Conventional technology]

Contact lenses are generally classified into hard contact lenses and soft contact lenses. Furthermore, soft contact lenses are classified into hydrated soft contact lenses and non-hydrated soft contact lenses. still,
In this specification, a water-containing soft contact lens is simply referred to as a "soft contact lens J," and a non-water-containing soft contact lens is simply referred to as a "non-water-containing soft contact lens."

Among contact lenses, soft contact lenses are
It is necessary to store it in a special storage solution.

As such a preservation solution, for example, Japanese Patent Publication No. 59-391
There is a storage and cleaning solution for soft contact lenses described in No. 39. This preservation/cleaning solution has a 0.85 to 0.95
After filling the container with a saline solution containing w/v% salt and sealing it,
It is obtained by sterilizing cobalt-60 by irradiating it with gamma rays.

[Problem to be solved by the invention]

However, when soft contact lenses are stored in the above-mentioned storage/cleaning solution, there is a drawback that the shape of the contact lenses tends to change.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an aqueous solution for storing, rinsing, etc. of contact lenses that does not change the shape of soft contact lenses even when the lenses are stored or rinsed, and is safe and easy to use.

[Means to solve the problem]

Therefore, in the present invention, the concentration of sodium chloride in the aqueous solution is Q, 8w/v% or less, and an osmotic pressure regulator is contained so that the osmotic pressure is substantially equivalent to that of lachrymal fluid, and this aqueous solution is further exposed to radiation. The present invention was completed by discovering that an aqueous solution obtained by sterilization achieves the above object.

The present invention will be explained in detail below.

The sodium chloride concentration in the aqueous contact lens solution of the present invention is 0.8 w/v% or less. Since the sodium chloride concentration of physiological saline is originally about 0.9%, most conventional aqueous solutions for soft contact lenses have been adjusted to around this concentration.

However, in the present invention, we have rejected this stereotype and found that by reducing the concentration of sodium chloride in the aqueous solution to 0.8 w/v% or less, it is possible to effectively prevent changes in the shape of soft contact lenses. .

Furthermore, the sodium chloride concentration in the aqueous solution for contact lenses of the present invention is preferably 0.5 to 0.65 w/v%.
is within the range of By setting the concentration within this range, changes in the shape of the soft contact lens can be more effectively prevented.

The aqueous solution for contact lenses of the present invention contains an osmotic pressure regulator in addition to sodium chloride. The content of the osmotic pressure adjusting agent is determined as appropriate so that the osmotic pressure of the aqueous solution becomes substantially equivalent to the osmotic pressure of lachrymal fluid. The osmotic pressure of tear fluid is approximately 2
Ranges from 40 to 340 mosm, typically around 270 mosm
~320m05m. Therefore, the osmotic pressure of the aqueous solution for contact lenses of the present invention is also adjusted within this range. If an aqueous solution outside the above range is used, the soft contact lens may expand or contract and the shape of the lens may change. In addition, in the case of non-hydrous soft contact lenses and hard contact lenses, the shape of the lens does not change, but if a contact lens with an aqueous solution attached is worn as it is, it will irritate the eyes.

The osmotic pressure may be measured by either the freezing point method (freezing point depression method, freezing point depression method) or vapor pressure method.

Examples of osmotic pressure regulators include inorganic compounds such as salts (potassium chloride, magnesium chloride, etc.), acids (hydrochloric acid, acetic acid, citric acid, etc.), and alkalis (sodium hydroxide, sodium citrate, etc.). Furthermore, boric acid, which is a mixture of the above compounds and is generally known as a buffering agent.
Borax, sodium phosphate-disodium phosphate, etc. can also be used as an osmotic pressure adjusting agent.

The pH of the contact lens aqueous solution of the present invention is preferably adjusted to around neutrality, for example in the range of 6 to 8, preferably 6.5 to 7.7. Also from this point of view, a buffer can be used as an osmotic pressure adjusting agent. Furthermore, to adjust the pH, acids such as hydrochloric acid, acetic acid, and citric acid, and alkalis such as sodium hydroxide and sodium citrate can also be used. In addition, from the viewpoint of imparting a stable pH to the aqueous solution for contact lenses of the present invention, it is more preferable to use a buffer as the osmotic pressure adjusting agent.

The aqueous solution is sterilized by radiation.

The radiation used for radiation sterilization includes alpha rays, beta rays,
Examples include gamma rays, X-rays, and electron beams. All of these radiations are effective because they have sterilizing ability, but β rays, γ rays, and electron rays are particularly used practically. For example, for sterilization with gamma rays, cobalt-60 or cesium-137 can be used as a radiation source.

The amount of radiation irradiation is suitably 0.5 to 6 Mrad, preferably 1 to 4.5 Mrad, from the viewpoint of being sufficient for sterilization and not having any adverse effects on containers and the like. An aqueous solution sterilized within this range has good sterilization properties and is therefore suitable for long-term storage (in an unopened state).

Radiation sterilization is preferably performed after the aqueous solution is filled into a suitable container and sealed. This container is approximately 2
It can be a small container for ~201 nl product, or even a larger container. However, it is preferable to use the entire amount of the aqueous solution in the container in one use, and in the case of a small container, the entire amount can be used at one time, which has the advantage that fungi will not grow in the liquid. . Furthermore, large containers are suitable for use in large quantities at one time, such as in hospitals.

However, it can also be dispensed aseptically into small containers for the product after sterilization.

The material of the container may be any material as long as it transmits radiation and does not deteriorate due to radiation. For example, it can be made of polymeric materials such as polyethylene, polystyrene, polyester, etc., glass, ceramics, and metals such as aluminum.

The aqueous solution for contact lenses of the present invention can be used as a storage solution and a rinsing solution for soft contact lenses, a rinsing solution for non-hydrous soft contact lenses and hard contact lenses, and the like.

〔Effect of the invention〕

Even when the aqueous contact lens solution of the present invention is used for storing or rinsing soft contact lenses, it does not cause any change in the shape of the lenses.

Furthermore, since it has an osmotic pressure substantially equivalent to that of lachrymal fluid and is sterilized, it is highly safe for the eyes and easy to use.

〔Example〕

The present invention will be explained in more detail below using examples.

Example 1.2 and Comparative Example 1.2 After dissolving each component of the following formulation in purified water, 101n
! Filled and sealed in a polyethylene container, exposed to cobalt-60 gamma rays 1. It was sterilized by irradiation with OMrad.

However, the aqueous solution of Comparative Example 2 was not sterilized by gamma rays.

HOY was added to each of the obtained aqueous solutions of Example 1.2 and Comparative Example 1.
Soft contact lenses manufactured by A Corporation (trade name: Hoya Soft) were immersed and stored for 7 days, and changes in the diameter of the contact lenses were measured, as shown in FIG. From the results in Figure 1, it can be seen that in Examples 1 and 2, there was no change in the lens diameter;
It can be seen that the shape of the lens has not changed at all. On the other hand, regarding Comparative Example 1, it can be seen that the diameter of the lens decreases over time and the shape of the lens changes. moreover,
When the lens of Comparative Example 1 was worn after immersion storage, the feeling of wearing the lens deteriorated.

Separately, the aqueous solutions of Example 2 and Comparative Example 2 after being left for 10 days were checked for the presence of bacteria based on the sterility test method of the Japanese Pharmacopoeia, and the results are shown in Table 1. the result,
The aqueous solution of Example 2 was confirmed to be sterile, but the aqueous solution of Comparative Example 2 was confirmed to contain both bacteria and fungi.

The osmotic pressure of each aqueous solution was measured using an osmotic pressure meter 08M manufactured by Shimadzu Corporation.
-1 type.

Example 1 (γ-ray irradiation) Sodium chloride 0.50w/v% potassium chloride
0. lOw/v% boric acid 0.50
w/v%borax 0.05w/v%p
H7,4 Osmotic pressure example 2 (γ-ray irradiation) Sodium chloride phosphate-sodium phosphate H Osmotic pressure comparison example 1 (γ-ray irradiation) Sodium chloride H Osmotic pressure comparison example 2 (no γ-ray irradiation) Sodium chloride Sodium phosphate Disodium phosphate H Osmotic pressure 2 7 6 mOsm Q, 60 w/v% 0.45 w/v% 0.20 w/v% 7.2 2 8 9 m05m 0.90 w/v% 5.5 2 8 9 m05m 0.60w/v% 0.45w/v% 0, 20 v/v% 7.2 2 8 9 mOsm Table 1 1: Not present, +: Present

[Brief explanation of drawings]

FIG. 1 shows changes over time in the diameters of soft contact lenses immersed and stored in each aqueous solution of Example 1.2 and Comparative Example 1.

Claims (1)

[Claims] An aqueous solution for contact lenses obtained by radiation sterilizing an aqueous solution containing 0.8 w/v % or less of sodium chloride and an osmotic pressure regulator so that the osmotic pressure is substantially equivalent to that of lachrymal fluid.