WO2001057172A1

WO2001057172A1 - Composition of multi-purpose solution for treating contact lens

Info

Publication number: WO2001057172A1
Application number: PCT/KR2001/000141
Authority: WO
Inventors: Jong Woo Park; Sang Heon Lee; Jae Young Jung
Original assignee: Choongwae Pharma Corporation
Priority date: 2000-02-01
Filing date: 2001-02-01
Publication date: 2001-08-09
Also published as: KR20010077222A; KR100354606B1; AU3238201A

Abstract

The present invention relates to a composition of multi-purpose solution for treating contact lens. Particularly, it relates to a composition of multi-purpose solution for treating contact lens containing 0.005∩10 wt% of polysaccharide of molecular weight higher than 5,000 Daltons as a nonenzymatic protein remover; 0.01∩10 wt% of non-ionic surfactant; and 0.00001∩1 wt% of polymeric preserver. A composition of multi-purpose solution for treating contact lens of the present invention can treat washing, sterilization, preservation and protein removal at the same time and have no side-effect caused by solution remnant.

Description

COMPOSITION OF MULTI-PURPOSE SOLUTION FOR TREATING CONTACT

FIELD OF THE INVENTION

The present invention relates to a multi-purpose solution for treating contact lenses, which is able to effectively remove protein deposits from the lenses without causing distortion of lenses and to simultaneously show disinfective and preservative effects of the lenses for a long period of time, thereby extending the wearing time and lifetime of the lenses, and ensure safety and convenience to the user .

BACKGROUND OF THE INVENTION

In recent times, contact lenses have been frequently used for aesthetic and other reasons. Owing to their material characteristics, contact lenses are likely to allow on their surfaces the formation of deposits attributed to external factors, such as mascara, hair spray materials, etc., and internal factors, such as tear proteins, mucous, lipids, etc. Such deposits on contact lenses deteriorate the wearing comfort as felt by the user, and impair the eyesight of the user, in addition to reducing the lifespan of the contact lenses and the time period for which the user can continuously wear the contact lenses. In a serious case, the deposits cause conjunctivitis. After use, therefore, the contact lenses must be cleaned and disinfected regularly to remove the deposits therefrom.

Conventionally, the washing, disinfection and storage of contact lenses were conducted in separate processes. Requiring a long period of time, this treatment procedure, however, is vexatious to the user. To circumvent these problems, there have been developed a variety of multipurpose solutions that can perform the cleansing, disinfection, protein removal, and storage of contact lenses at the same time. Demand for multi-purpose solutions for contact lenses are increasing steadily by those reason. On the whole, contact lenses are largely classified into hard contact lenses, soft contact lenses, and RGP

(rigid gas permeable) contact lenses. Particularly, soft contact lenses, which are the most extensively used at present, are subclassified into four groups according to the water content and ion character of the lens material: Group I is characterized by the existence of no ions on the surface of the lens and by a water content of less than 50 % ; Group II is non-ionic with a water content of 50 % or greater; Group III is ionic with a water content of less than 50 %; and Group IV is ionic with a water content of 50 % or greater. Depending on material properties of contact lenses, they are different in the extent and amount of pollutants (e. g., proteins) deposited thereon and the degree of cleanliness achievable by cleansing procedures. Owing to their ionic characteristic, in particular, Group IV lenses are reported to allow the deposition of a large quantity of proteins and associate so strongly with proteins that they are seldom removed upon cleansing (L. Minarik et al., CLAO J., 15(3), (1989), 185-188; G. E. Minno et al . , Optom. and Vis. Sci., 68(11), (1991) 865-872).

Of the deposits adherent to lenses, lipids are easily removed with ordinary solutions for contact lenses, whereas proteins are difficult to remove owing to their strong association with lenses. Most of the side effects of contact lenses are attributed to protein deposits . Therefore, it is very important to effectively remove proteins adhering to lenses.

Main proteins contained in human tears are exemplified by lysozyme, albumin, lactoferrin, glycoprotein, and mucin. It is reported that lysozyme is easily removed with ordinary multi-purpose solutions for contact lenses, but albumin and mucin are not (L. Minarik et al . , CLAO J. , 15(3), (1989) 185-188; J. Jung et al . , CLAO J. , 19(1), (1993) 47-49). To be useful in cleansing and disinfecting contact lenses, multi-purpose solutions must be enhanced in the ability to remove albumin and lactoferrin as well as lysozyme.

In an effort to improve the ability of multi-purpose solutions to remove proteins, proteinases were utilized. For example, U. S. Pat. No. 5,785,767 discloses a cleaning and disinfecting solution for contact lenses which comprises a proteolytic enzyme and polyhydric alcohol such as glycerin or propylene glycol, asserting that this solution ensures complete disinfection and protein removal of lenses within a very short period of time (about 5 min) . Since multi-purpose solutions for contact lenses generally have contact lenses immersed therein for about 4 hours, in some cases, for about 8 hours, for disinfection and storage according to their particular characteristics, the components of the solutions may be adsorbed or deposited onto the lenses during the immersion time. During the wearing of the contact lenses, the adsorbed or deposited components are slowly released, causing various serious problems. Therefore, care must be taken in selecting the solution components. Particularly in the case of a product containing proteinase, the enzyme, if existing on the surface of the lens even at a trace amount, is likely to cause fatal damage to the eyes. Accordingly, various efforts have been made to develop multi-purpose solutions for contact lenses which contain no proteolytic enzymes, but show excellent protein removal ability. Commercially available, proteinase-free multi-purpose solutions for contact lenses are found to contain low- molecular weight additives, including low-molecular weight preservatives, low-molecular weight disinfectants, and low- molecular weight surfactants. These low-molecular weight additives are, however, adsorbed onto the surfaces or into pores of lenses, causing various problems. For example, such additives, when adsorbed onto contact lenses, may distort and discolor them to reduce the lifetime thereof. Additionally, the user is irritated at the eyes and feels uncomfortable when wearing the contact lenses contaminated with such additives. In a worse case, the eyes may be damaged fatally (B. J. Tripathi et al . , Lens and Eye Toxic. Res., 3 (4&4), (1992), 361-375). U. S. Pat. No. 4,820,352 refers to contact lens cleaning compositions comprising benzalkonium chloride, thimerosal, or sorbic acid as a germicidal agent. Now, these components are found to be easily adsorbed onto lens surfaces to irritate the eye of the user in addition to discoloring the lenses and thus reducing their lifetime (B. J. Tripathi et al . , Lens and Eye Toxic. Res., 3 (4&4), (1992), 361-375). Poloxamin, a polymeric surfactant which is generally used as a protein remover in ordinary solution for treating contact lenses, is weak in protein removal capability. U. S. Pat. No. 5,370,744 discloses a cleansing and disinfecting solution for contact lenses comprising a cleaning agent selected from polycarboxylates (M. . 90-600 Da) , polysulfonates and polyphosphates in combination with citrate, tartarate, succinate, or mixtures thereof. However, these salts are prohibited from being used in solutions for treating contact lens because they form complexes which may be harmful to the body (Handbook of Pharmaceutical Excipients, 2_nd Ed., 1994, American Pharmaceutical Association) . In addition, the solution of the cited patent does not have the viscosity required for multi-purpose solutions for contact lenses.

U. S. Pat. No. 5,451,303 introduces a method for removing protein deposits using different electrochemical potentials between two materials applied to opposites sides of the lens. According to the method, an oxidizing agent and a reducing agent are separately dissolved in a gel, after which the surface of lens is coated with the oxidizing gel, or reducing gel added the other gel to it for achieving protein removal. This method is inefficient in both convenience and cost aspects because of the requirements of coating lenses with gels, heating at 80 °C or higher for cleansing, and separate storage of the oxidizing gel and reducing gel . U. S. Pat. No. 5,858,937 provides a multi-purpose, contact lens-treating composition comprising a phosphonic compound as a removing or preventing agent of protein deposits, which can cleanse, disinfect, store and rinse all types of contact lenses, including hard lenses, soft lenses and RGP lenses. In practice, the composition was found to be poor in protein removal ability. Particularly from the soft lenses that have high water contents or ion characteristics, the composition can remove protein deposits only at a very low rate. U. S. Pat. No. 5,897,833 describes a system for disinfecting a contact lens, which includes a first container section holding containing hydrogen peroxide and a second container section containing a hydrogen peroxide destroying component, wherein the contact lens is first disinfected by use of the hydrogen peroxide solution and then, any hydrogen peroxide is removed from the lens by the destroying component to prevent the hydrogen peroxide- induced side effects such as irritation and edema. However, this system is inefficient in that separate containers are required to hold different solutions and a two-step cleansing procedure is needed.

PCT Publication No. 95/01414 suggests a multi-purpose solution for treating contact lenses comprising non-ionic surfactant and quaternary ammonium phosphate ester. Poloxamer (polyoxypropylene-polyoxyethylene copolymer) is superior in removing non-protein deposits such as lipids and inorganic matters, but poor in protein removal ability.

As described above, commercially available multipurpose contact lens-treating solutions contain a large quantity of proteolytic enzymes or, in the case of containing no proteolytic enzymes, are destitute of or poor in protein removal ability.

SUMMARY OF THE INVENTION

Leading to the present invention, the intensive and thorough research on multi-purpose solutions for treating contact lenses, conducted by the present inventors, resulted in the finding that a polysaccharide with a molecular weight of 5,000 or higher in combination with polymeric non-ionic surfactant and a polymeric preservative ensures effective protein removal, as well as ensuring safety and convenience to the user.

Therefore, it is an object of the present invention to overcome the above problems encountered in prior arts and to provide a multi-purpose solution for treating contact lenses, which can effectively remove protein deposits from contact lenses and ensure safety and convenience to the user.

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized by employment of a polysaccharide with a molecular weight of 5,000 Daltons or greater as a non-enzymatic protein remover in combination with a non-ionic surfactant and a polymeric preservative. A detailed description will be given of these components, below.

In one embodiment of the present invention, the above object could be accomplished by a provision of a ulti- purpose solution for treating contact lenses, comprising 0.005-10 % by weight of a polysaccharide with a molecular weight of 5,000 or higher to remove protein deposits from the contact lenses, 0.01-10 % by weight of a non-ionic surfactant, and 0.00001-1 % by weight of a polymeric preservative.

In one version of the embodiment, the multi-purpose solution for treating contact lenses further comprises a stabilizer and a buffer.

1. Protein Remover

For use as a protein removal in the present invention, a polysaccharide with a molecular weight of 5,000 Daltons or larger is selected from the group consisting of hyaluronic acid (l->3) -0- (β-glucuronic acid) - ( 1→4 ) -0-2-acetamido-2- deoxy-β-D-glucose) , sodium hyaluronate, and chondroitin sulfate. All of these polysaccharides are naturally occurring glycosaminoglycans . Hyaluronic acid or its sodium salt is made up of disacchride repeating units consisting of D-glucuronic acid and N-acetyl-D-glucosamine . There are two kinds of chondroitin sulfate: chondroitin-4-sulfate [(l->4)- 0- (β-D-glucopyranosyl uronic acid) - ( l-3) -0- (2-N-acetamido- 2-deoxy-β-D-galactopyronosyl-4-sulfate) ] and chodroitin-6- sulfate [ (1-.4) -0- (β-D-glucopyranosyl uronic acid) - (l-»3) -0- (2-N-acetamido-2-deoxy-β-D -galactopyranosyl-6-sulfate) ] . In structures of these chondroitin sulfates, β-D-glucuronic uronic acid and α-D-N-galactozamine are alternately linked to each other to some extent.

In accordance with the present invention, the non- enzymatic protein remover is preferably used in an amount of 0.005 to 10 % by weight based on the weight of the solution and more preferably in an amount of 0.01-5 % by weight. For instance, less than 0.005 % by weight of the polysaccharide is too small to effectively remove protein deposits from contact lenses. On the other hand, if the polysaccharide is used in an amount greater than 10 % by weight, the resulting solution is too viscous for the user to conveniently handle.

In addition to being able to remove tear-derived proteins, such as lysozyme, albumin and mucin, which render the eyesight of the user vague, cause the eye to be blood- shot, and make the user feel eye irritation, the non- enzymatic protein remover does not adsorb to contact lenses nor distort them. Found in the body, the polysaccharide causes no side effects such eye irritation. Being reported to show non-Newtonian viscosity and be effective for the treatment of xerophthalmia and as a lubricant for joints, the polysaccharides are suitable for use in multi-purpose solutions for treating various contact lenses, including soft lenses, hard contact lenses that are likely to irritate the eye owing to their material properties, and RGP contact lenses (E. Gura et al . , Polymer Degradation and Stability, 59, (1998) , 297-302) .

2. Non-Ionic Surfactant

Useful in the present invention is a non-ionic surfactant with a molecular weight of 5,000 or larger. Preferably, the non-ionic surfactant is selected from the group consisting of polyethylene oxide-co-polypropylene oxides and tetra [polyoxyethylene-co- polyoxypropylene] ethylenediamine block copolymers. Preferred examples of the poly-ethylene oxide-co- polypropylene oxides include those that have average molecular weights of 8,350 such as poloxamer 188 (ethylene oxide content 82.0 wt%), 12,000 such as poloxamer 338 (ethylene oxide content 73.0 wt%) , and 15,000 such as poloxamer 407 (ethylene oxide content 83.0 wt%). As for the tetra [polyoxyethylene-co-polyoxypropylene] ethylenediamine block copolymers, their preferable examples include those that have average molecular weights of 6,700 such as tetronic 904 (ethylene oxide content 60.0 wt%, 15,000 such as tetronic 1107 (ethylene oxide content 70.0 wt%), and 25,000 Da such as tetronic 908 (ethylene oxide content 60.0 wt%) .

Protective of the lenses, the non-ionic surfactant forms foam and acts to remove contaminants such as lipids and inorganic matters. All of the above-exemplified surfactants are water-soluble, little irritative to the eye and do not interact with other additives.

In accordance with the present invention, the non- ionic surfactant is preferably used in an amount of 0.01 to 10 % by weight based on the total weight of the multipurpose solution for treating contact lenses and more preferably in an amount of 0.1-5 % by weight. For example, when it is present at an amount of less than 0.01 % by weight, the non-ionic surfactant cannot protect the lens sufficiently, forms little foam, and makes the user feel uncomfortable. On the other hand, a content of larger than 10 % by weight of the non-ionic surfactant results in too high a viscosity to handle the resulting solution conveniently. 3. Polymeric Preservative

In the solution of the present invention, a polymeric preservative is contained in order to disinfect and preserve the lens. Preferred is a hydrolyzed collagen derivativative or a water-soluble compound. In detail, the polymeric preservative is preferably selected from the group consisting of lauryldimonium hydroxypropyl hydrolyzed collagen, cocodimonium hydroxypropyl hydrolyzed collagen, stearyldimonium hydroxypropyl hydrolyzed collagen, poly (oxyethylene (dimethylamino) ethylene (dimethylimino) ethyle ne dichloride) , polyaminoproyl diguanide and polyquaternium- 16.

The amount of the polymeric preservative preferably falls within the range of 0.00001 to 1.0 % by weight and particularly preferably within the range of 0.0001 to 0.1 % by weight. For instance, less than 0.00001 % by weight of the polymeric preservative shows only little disinfective and preservative effects while larger than 1.0 % by weight of the polymeric preservative may cause irritation to the eye .

In contrast to the preservative compounds used in conventional contact lens-treating solutions, such as sorbic acid, thimerosal and benzalkonium chloride, the preservative of the present invention brings about potent disinfective and preservative effects without discoloration of the lens nor irritation to the eye.

4. In accordance with another embodiment, the multipurpose solution of the present invention further comprises a stabilizer and a buffer, which are usually used in conventional contact lens solutions.

As a useful stabilizer, ethylenediamine tetraacetic acid disodium, ethylenediamine tetraacetic acid trisodium, or ethylenediamine tetraacetic acid tetrasodium may be selected. Playing a role in stabilizing and preserving the main components, the stabilizer may be preferably used in an amount of 0.01 to 0.5 % by weight based on the total weight of the solution. For example, when too little stabilizer is used, no effects can be obtained therefrom. On the other hand, if the multi-purpose solution contains larger than 0.5 % by weight of the stabilizer, irritation to the eye may occur .

Useful in the present invention is a buffer selected from the group consisting of a borate buffer, a phosphate buffer, and a carbonate buffer. Preferably, the buffer has a pH range of 6.0 to 8.0.

It is preferred that sodium chloride is used to make the contact lens-treating solution isotonic.

The multi-purpose solution for treating contact lenses of the present invention can be applied to all types of contact lenses, including soft contact lenses, hard contact lenses, and RGP (Rigid Gas Permeable) contact lenses. With the solution of the present invention, these contact lenses can be cleansed, disinfected, rinsed, stored and freed of protein deposits.

EXAMPLES

A better understanding of the present invention may be obtained in light of the following examples which are set forth to illustrate, but are not to be construed to limit the present invention.

F.VM T.F. 1 _: Preparation of Multi-Purpose Solution for Treating Contact Lenses I

In distilled water were completely dissolved 0.058 g of disodium hydrogen phosphate, 0.055 g of potassium hydrogen phosphate, and 0.90 g of sodium chloride, along with 0.125 g of ethylenediamine tetraacetic acid disodium as a stabilizer. Afterwards, to the solution (pH 6.90), 0.0001 g of polyaminopropyldiguanide was added as a preservative, followed by slowly adding 1 g of a polyethylene oxide-co- polypropylene oxide with an average molecular weight of 8,350 (poloxamer 188, ethylene oxide content 82.0 wt%) as a non-ionic surfactant. After completion of dissolution of the components, 0.02 g of sodium hyaluronate was added as a protein remover with stirring. Filtration through 0.2 μm filter yielded a multi-purpose solution for treating contact lenses.

F.^y& PT.F. 2: Preparation of Multi-Purpose Solution for Treating Contact Lenses II

Except that 2.0 g of polyethylene oxide-co- polypropylene oxide with an average molecular weight of 8,350 (poloxamer 188, ethylene oxide content 82.0 wt%) as a non-ionic surfactant and 0.1 g of sodium hyaluronate as a protein remover were added, the same procedure as in Example 1 was conducted to prepare a multi-purpose solution for treating contact lenses.

T-fl^yftMPT.T**. 3: Preparation of Multi-Purpose Solution for Treating Contact Lenses III

Except that 1.0 g of polyethylene oxide-co- polypropylene oxide with an average molecular weight of 8,350 (poloxamer 188, ethylene oxide content 82.0 wt%) as a non-ionic surfactant and 0.02 g of chondroitin sulfate as a protein remover were added, the same procedure as in Example 1 was conducted to prepare a multi-purpose solution for treating contact lenses .

f.yaMPj. 4: Preparation of Multi-Purpose Solution for Treating Contact Lenses IV

Except that 1.0 g of polyethylene oxide-co- polypropylene oxide with an average molecular weight of 8,350 (poloxamer 188, ethylene oxide content 82.0 wt%) as a non-ionic surfactant and 0.1 g of chondroitin sulfate as a protein remover were added, the same procedure as in Example 1 was conducted to prepare a multi-purpose solution for treating contact lenses.

^yA PT.F : Preparation of Multi-Purpose Solution for Treating Contact Lenses V

A multi-purpose solution for treating contact lenses was prepared in a manner similar to that of Example 1, except that 1.0 g of tetra [polyoxyethylene-co- polyoxypropylene] ethylenediamine block copolymer with an average molecular weight of 15,000 Da (tetronic 1107, ethylene oxide content 70 wt%) as a non-ionic surfactant and 0.02 g of sodium hyaluronate as a protein remover were used. T.VAMPT.F. 6: Preparation of Multi-Purpose Solution for Treating Contact Lenses VI

A multi-purpose solution for treating contact lenses was prepared in a manner similar to that of Example 1, except that 2.0 g of tetra [polyoxyethylene-co- polyoxypropylene] ethylenediamine block copolymer with an average molecular weight of 15,000 (tetronic 1107, ethylene oxide content 70 wt%) as a non-ionic surfactant and 0.1 g of sodium hyaluronate as a protein remover were used.

F,?CAMPT.F. 7: Preparation of Multi-Purpose Solution for Treating Contact Lenses VII

A multi-purpose solution for treating contact lenses was prepared in a manner similar to that of Example 1, except that 1.0 g of tetra [polyoxyethylene-co- polyoxypropylene] ethylenediamine block copolymer with an average molecular weight of 15,000 (tetronic 1107, ethylene oxide content 70 wt%) as a non-ionic surfactant and 0.02 g of chondroitin sulfate as a protein remover were used.

EXAMPLE 8: Preparation of Multi-Purpose Solution for Treating Contact Lenses VIII

li A multi-purpose solution for treating contact lenses was prepared in a manner similar to that of Example 1, except that 2.0 g of tetra [polyoxyethylene-co- polyoxypropylene] ethylenediamine block copolymer with an average molecular weight of 15,000 (tetronic 1107, ethylene oxide content 70 wt%) as a non-ionic surfactant and 0.1 g of chondroitin sulfate as a protein remover were used.

Compositions of the multi-purpose solutions for treating contact lenses prepared in above examples are summarized in Table 1, below.

TABLE 1

Compositions of Multi-Purpose Solutions for Treating Contact

Lenses

PEO: polyethylene oxide

PPO: polypropylene oxide

EO: ethylene oxide

PAPD: polyaminopropyldiguamde

E4AA2Na : Ethylenetetraacetic acid disodium

2NaHP: Disodium hydrogen phosphate

CaHP: calcium hydrogen phosphate

4 (POE/POP) Etdiamine : polyoxyethylene/polyoxypropylene) ethylenediamine block copolymer

PREPARATION EXAMPT. ^• Preparation of Artificial Tear Solution

After being filtered through a 0.45 μm membrane filter, a phosphate buffer was incubated at 37 °C for 60 mm. In 100 ml of the filtered phosphate buffer, 3.6 mg of calcium chloride dihydrate was dissolved with stirring, followed by incubation at 37 °C for 45 min. The resulting solution was slowly added with 200 mg of lysozyme with stirring, and incubated for 30 min. Following the slow addition of 100 mg of mucin, the solution was allowed to stand for 5 min. Finally, 17.47 mg of albumin was added to the solution which was then adjusted to pH 7.2.

EXPERIMENTAL EXAMPLE 1 : Protein Removal Effect on Soft Contact Lens Group I

An examination was made of the ability of the multipurpose solutions of the present invention to remove protein deposits on soft contact lenses of Group I (EDGER III, water content 35 %, Ocular Sciences) .

2 ml of the artificial tear solution prepared in Preparation Example, in which a new contact lens which had not been used at all was immersed, was agitated at 60 rpm for 24 hours in a water bath maintained at 37 °C to deposit proteins on the lens. Then, the lens was put on the palm and added with 6 drops of the solutions of Examples 1 to 8, after which each surface of the lens was scrubbed back and forth 10 times using the middle finger. After rinsing, the contact lens was stored for 8 hours in the multi-purpose solution. Quantification of the protein deposited on the lens was performed using ninhydrin and, based on the quantitative data obtained, protein removal rate (%) was calculated according to the following equation 1.

EQUATION 1

(protein content before cleansing

Protein removal - protein content after cleansing) rate (%) x loo protein content before cleansing

As a control, a commercially available product (U. S. Pat. No. 5,858,937) comprising phosphonate as a protein remover was used. The results are given in Table 2, below.

TABLE 2

Protein Removal Percentage for Soft Contact Lens Group I

. mean values of 15 experimental measurements

Over the conventional product (protein removal rate

18 . 7 % ) , the multi-purpose solutions for treating contact lenses of the present invention were far superior in protein removal ability as demonstrated by their measurements ( 58 -

65 % ) in Table 2 .

EXPERIMENTAL EXAMPLE 2 : Protein Removal Effect on Soft Contact Lens Group IV

An examination was made of the ability of the multipurpose solutions of the present invention to remove protein deposits on soft contact lenses of Group IV (Scustom™, water content 55 %, Specialty Ultravision Inc.).

In this regard, the experiment was conducted with the same procedure as in Experimental Example 1. As comparative examples, there were employed commercially available products which comprised as protein removers phosphonate (U. S. Pat. No. 5,858,937) and a proteolytic enzyme subtilisin (CompleteR, Allergan) . The results are given in Table 3, below.

TABLE 3 Protein Removal Percentage for Soft Contact Lens Group IV

mean values of 15 experimental measurements

As seen in Table 3, the commercially available product which aimed only to wash contact lenses was measured to have a protein removal rate of as low as 4 % . Even the product containing the proteolytic enzyme could remove protein deposits from soft contact lens group IV at a rate of only 12.6 % . In contrast, the solutions of the present invention were measured to range in protein removal rate from 30 to 36 %. In consequence, the solutions of the present invention were identified as being superior in protein removal ability.

EXPERIMENTAL EXAMPLE 3: Protein Removal Effect on RPG Contact Lenses An examination was made of the ability of the multipurpose solutions of the present invention to remove protein deposits from RPG contact lenses (RPG specialty, Specialty Ultravision Inc.).

In this regard, the experiment was conducted with the same procedure as in Experimental Example 1. As a comparative example, there was employed a commercially available product which comprised phosphonate (U. S. Pat. No. 5,858,937) as a protein remover. The results are given in Table 4, below.

TABLE 4

Protein Removal Percentage for RPG Contact Lenses

mean values of 15 experimental measurements

As seen in Table 4 , the commercially available product comprising phosphonate as a protein remover was measured to have a protein removal rate of 29.8 % on RGP contact lenses. In contrast, the solutions of the present invention were increased in protein removal rate by at least 10 % as measured to range from 30 to 36.2 %.

EXPERIMENTAL EXAMPT.F. 4 : Disinfective and Preservative Effect

Using a film plate (3M, ptrifilm™ plate) , the multipurpose solutions of the present invention were examined for disinfective and preservative effect.

After tucking up the upper film of the petrifilm plate, 1 ml of a prepared sample was inoculated perpendicularly on the center of the lower film. The upper film was returned to its original position, covering the lower film wholly. Gently pressing the petrifilm plate by use of a board resulted in the formation of gel. The petrifilm was incubated at 32 °C for 48 hours if it was designed for general bacteria, or at 25 °C for 5 days if it was designed for fungi or yeasts. After completion of the incubation, the counts of microbial cells were observed under an optical microscope to determine the disinfective and preservative ability of the solutions. As a control, distilled water was used. The results are given in Table 5, below.

TABLE 5 Disinfective and Preservative Effect

No germs -

10 or fewer germ cells + fewer than 100 germ cells ++ 100 or more germ cells +++

As apparent in Table 5, the multi-purpose solutions for treating contact lenses of the present invention did not allow germs to proliferate at all, whereas distilled water permitted germs to thrivingly proliferate. Therefore, the multi-purpose solutions of the present invention were identified as being superior in not only killing germs existing on lenses, but also preserving the lenses free of germs for a long period of time.

EXAMPLE 5: Eye Irritation Test

To determine their safety to the body, the multi- purpose solutions for treating contact lenses of the present invention were tested for eye irritation according to rules set by the National Institute of Safety Research, Korea, as follows.

Before testing, rabbits (New Zealand White) were examined for abnormality in their eyes with the naked eye and with the aid of an ophthalmoscope. Each group of nine normal rabbits (2.5±0.5 kg) was administered with samples by dropping 100 μl of each sample onto the left eye. Of the nine rabbits in each group, the eyes of the rest three were washed with biologically active saline for 1 min beginning 20-30 sec after administration of sample, while the other six members were allowed to remain untreated. The right eye that was not administered with samples was used as a control. 1, 2, 3, 4, 6, 24, 48 and 72 hours after the application of the samples, the left eyes of the rabbits were observed with the naked eye, by use of a hand lamp, and with the aid of an ophthamoscope . The results are given in Table 6, below.

TABLE 6

Eye Irritation Test Result

*T . S . : total eye stimulus index M. O . I . : mean of eye stimulus index

It is apparent from the data of Table 6 that the multi-purpose solutions for treating contact lenses of the present invention were determined not to irritate the eye even 72 hours after the application thereof and thus identified as being safe to the body .

INDUSTRIAL APPLICABILITY

As described hereinbefore, the multi-purpose solutions for treating contact lenses of the present invention are able to effectively remove protein deposits from the lenses without causing distortion of lenses and to continuously show disinfective and preservative effects of the lenses for a long period of time, thereby extending the wearing time and lifetime of the lenses. In addition, since they do not contain eye-irritative materials such as proteolytic enzyme, phosphonate, hydrogen peroxoide, etc., nor irritative low- molecular weight additives such as low-molecular weight preservatives, disinfectants, surfactants, etc., the multipurpose solutions of the present invention are safe to the body with prevention of eye irritation due to lenses and solutions therefor. Further, the multi-purpose solutions of the present invention exert excellent disinfective and preservative effects on hard contact lenses, that that are likely to irritate the eye owing to their material properties, and RPG contact lenses, as well as on soft lenses. Moreover, the solutions of the present invention are economically favorable because they can wash, rinse, disinfect, preserve and store contact lenses at once without separate means or tools.

The present invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

What is claimed is:

1. A multi-purpose solution for treating contact lenses, comprising: 0.005-10 % by weight of a polysaccharide with a molecular weight of 5,000 or larger as a protein remover; 0.01-10 % by weight of a non-ionic surfactant; and 0.00001-1 % by weight of a polymeric preservative.

2. The multi-purpose solution as set forth in claim 1, further comprising a stabilizer and/or a buffering agent.

3. The multi-purpose solution as set forth in claim 1, wherein the polysaccharide, have a average molecula weight of 5000 or large, is selected from the group consisting of hyaluronic acid, sodium hyaluronate, and chondroitin sulfate.

4. The multi-purpose solution as set forth in claim 1, wherein the non-ionic surfactant have a average molecular weight of 5,000 or larger and is selected from the group consisting of a polyethylene oxide-co-polypropylene oxide, and a tetra [polyoxyethylene-co- polyoxypropylene] ethylenediamine block copolymer.

5. The multi-purpose solution as set forth in claim 4, wherein the polyethylene oxide-co-polypropylene oxide is selected from the group consisting of those that have average molecular weights of 8,350 (poloxamer 188, ethylene oxide content 82.0 wt% ) , 12,000 (poloxamer 338, ethylene oxide content 73.0 wt%), and 15,000 (poloxamer 407, ethylene oxide content 83.0 wt%).

6. The multi-purpose solution as set forth in claim 4, wherein the tetra [polyoxyethylene-co- polyoxypropylene] ethylenediamine block copolymer is selected from the group consisting of those that have average molecular weights of 6,700 (tetronic 904, ethylene oxide content 60.0 wt%) , 15,000 (tetronic 1107, ethylene oxide content 70.0 wt%), and 25,000 (tetronic 908, ethylene oxide content 60.0 wt%) .

7. The multi-purpose solution as set forth in claim 1, wherein the polymeric preservative is selected from the group consisting of lauryldimonium hydroxypropyl hydrolyzed collagen, cocodimonium hydroxypropyl hydrolyzed collagen, stearyldimonium hydroxypropyl hydrolyzed collagen, poly (oxyethylene (dimethylimino) ethylene (dimethylimino) ethyle ne dichloride) , polyaminoproyl diguanide and polyquaternium- 16.

8. The multi-purpose solution as set forth in claim 2, wherein the stabilizer is selected from the group consisting of ethylenediamine tetraacetic acid disodium, ethylenediamine tetraacetic acid trisodium, and ethylenediamine tetraacetic acid tetrasodium.

9. The multi-purpose solution as set forth in claim 2, wherein the stabilizer is contained in an amount of 0.01 to 0.5 % by weight.

10. The multi-purpose solution as set forth in claim 2, wherein the buffer is selected from the group consisting of a borate buffer, a phosphate buffer, and a carbonate buffer.

11. The multi-purpose solution as set forth in claim 2, wherein the buffer has a pH range of 6.0 to 8.0.

12. The multi-purpose solution as set forth in claim 1, wherein the multi-purpose solution performs washing, disinfection, preservation, and protein removal, at once, for soft contact lenses, hard contact lenses, and rigid gas permeable contact lenses .