WO1996000275A1

WO1996000275A1 - Contact lens cleaning compositions with solubilized polymers

Info

Publication number: WO1996000275A1
Application number: PCT/US1995/007482
Authority: WO
Inventors: Sam W. Lam; J. Abraham M. Espiritu
Original assignee: Allergan
Priority date: 1994-06-23
Filing date: 1995-06-13
Publication date: 1996-01-04
Also published as: AU2825795A

Abstract

Compositions and methods for removing proteinaceous deposit material from the surface of a contact lens are disclosed. The compositions comprise an enteric polymeric component in an amount effective to remove the proteinaceous debris from the lens. The polymer-containing composition is combined with a liquid aqueous medium when used to clean the contact lens. Examples of such polymeric components are those which are anionic and soluble in the liquid aqueous medium, and include polymethacrylates and copolymers thereof. The polymer is believed to bind proteins, such as lysozyme, on the contact lens thereby removing the proteins from the lens surface.

Description

CONTACT LENS CLEANING COMPOSITIONS WITH SOLUBILIZED POLYMERS

Background of the Invention

The present invention relates to compositions and methods for treating, for example, cleaning, contact lenses. More particularly, the invention relates to compositions including certain polymers for treating contact lens, for example, for removing proteinaceous deposit material from contact lenses.

Contact lenses need to be periodically treated, for example, cleaned, because of the tendency for a variety of materials to accumulate on the lenses. Among the materials that may accumulate on contact lenses are proteins, glycoproteins, lipids, as well as foreign matter, such as eye makeup. Unfortunately, many lens treating systems cause excessive lens wear and/or damage, such as when the system employs an abrasive component. Excessive wear due to the lens treating system is especially common with "soft" contact lenses because of the relatively low resistance to abrasion of such lenses. Accordingly, lens treatment systems that effectively perform their desired function, such as cleaning or disinfecting the lens, without causing undue lens wear are advantageous.

A number of cleaning systems have been proposed for contact lenses. For example, Su et al U.S. Patent No. 5,037,484 proposes the use of a cleaning composition that contains a particulate organic polymer or polysiloxane particles suspended in a carrier. The carrier usually includes a thickening agent in order to keep the polymeric particles in suspension. The thickening agent itself is not reported to have any cleaning effect on the contact lens. Due to the relative inelasticity or rigidity of these particles, it is not likely that they can provide sufficient softness to avoid lens abrasion or scratching. Another approach to treating contact lenses, in particular to disinfect contact lenses, is described by Schafer et al U.S. Patent No. 5,011,661. Microbes on the contact lens are destroyed by immersing the lens in a disinfecting solution. The disinfectant, such as hydrogen peroxide, is decomposed by contacting it with a catalytic neutralizing agent, which is typically enveloped by a polymeric coating that acts to retard the decomposition of disinfectant in a controlled fashion. This system is not reported to be effective in removing non-microbial debris, such as proteinaceous deposits, from the lens, so that a separate system of removal of these materials is required. Further, the polymeric coating on the neutralizing agent is not indicated to be effective in removing deposit materials from the contact lens.

Another approach proposed for cleaning contact lenses is described by Bhatia U.S. Patent Nos. 4,921,630 and 4,839,082 wherein a chemical formulation purportedly forms an abrasive precipitate when rubbed on the surface of the lens. The abrasive precipitate is believed to scour deposits from the lens as a user manually rubs the precipitate against the lens surface. One formulation includes a carboxy vinyl polymer in solubilized from, which polymer apparently precipitates from solution upon contacting the lens, hypothetically because of "water loss" from the polymer-containing composition and takeup of the water by the lens. Hence, the abrasive precipitate formed is believed to be composed primarily of precipitated polymer. The polymer is not believed to be effective in removing deposit materials from the contact lens other than by abrasion.

Yet another system for cleaning contact lenses is proposed by Chromecek et al U.S. Patent No. 4,655,957, which describes a particulate hydrophilic polymer or copolymer, typically in bead form, that is purportedly effective in removing lens deposits. Since the composition is only reported to be effective in removing lens deposits when provided in particulate form, it is likely the composition effects deposit removal by abrading the material from the lens surface. It would be advantageous to provide a contact lens treatment system that both effectively removes deposited materials from the contact lens and avoids detrimental abrasion or scratching of the lens.

Summary of the Invention

New compositions and methods for cleaning contact lenses have been discovered. The present compositions include an enteric polymeric component that is soluble in a liquid aqueous medium and is present in the medium in an amount effective to remove proteinaceous deposits from the contact lens. Because the enteric polymeric component is effective in removing proteinaceous deposits from the lens, other components effective for such purpose, in particular proteolytic enzymes, need not be present in the composition.

As used herein, an "enteric" polymer (or polymeric component) is a polymeric material which is insoluble and impermeable to water at a pH of 5 or less, has a solubility in an aqueous medium that varies with pH, and carries one or more negative charges when solubilized in an aqueous medium. The presently useful enteric polymeric components, which are preferably synthetic, are solubilized by forming soluble salts, preferably in aqueous media having substantial concentrations of salt ions. Such enteric polymeric components, which preferably include one or more ester groups per repeating polymer unit and/or form low viscosity (less than 100 cp) aqueous solutions containing about 10% by weight of the polymeric component, are clearly distinguished from other polymers, such as acid polymers and acid salt polymers, which are soluble over broader pH ranges and/or which form viscous gels at pHs of 5 or less and/or form highly viscous (greater than 100 or 1000 cp) solutions containing 10% by weight of such other polymers. The limited or controlled solubility of the presently useful enteric polymers provides an additional degree of control in practicing the present invention. For example, by controlling the pH and/or salt concentration of the aqueous medium one can effectively control the time during which such enteric polymeric components are effective in removing proteinaceous deposits from contact lenses. Preferably, the solubility of the presently useful enteric polymers in aqueous media increases with increasing pH over at least a portion to the pH range.

In one broad aspect, the present invention is directed to compositions useful for treating, for example, cleaning, a contact lens. The compositions comprise a liquid aqueous medium adapted to contact a contact lens in cleaning the lens, and an enteric polymeric component which is soluble in the liquid aqueous medium. In one embodiment, the composition, in particular the liquid aqueous medium, is substantially free of an oxidative disinfectant component. A contact lens can be contacted with the polymer-containing medium in order to clean the lens without also contacting the lens with a disinfectant component.

In another embodiment of the invention, the compositions comprise a liquid aqueous medium, an enteric polymeric component soluble in the medium, and a disinfectant component present in the liquid aqueous medium in a substantially constant amount^, that is effective to disinfect a contact lens contacted with the composition. The disinfectant component may be selected from oxidative disinfectant components, for example, hydrogen peroxide, chlorine dioxide, peroxy salts and mixtures thereof. Such a composition can be used to remove accumulated proteinaceous materials from the lens as well as to disinfect the lens.

In a particularly useful embodiment, the present compositions comprise at least one solid article (for example, a tablet, pill, pellet or a plurality of particles (such as granules) ) that includes an enteric polymeric component soluble in a liquid aqueous medium. The enteric polymeric component is preferably distributed throughout the at least one solid article in an amount effective to remove proteinaceous material from the contact lens when the lens is contacted with a liquid aqueous medium containing the enteric polymeric component present in solubilized form. More preferably, the enteric polymeric component is distributed substantially uniformly throughout the at least one solid article, such as when the solid article is formed by compressing a mass of precursor material having substantially the same chemical makeup as the at least one solid article.

In a preferred aspect, the present compositions are substantially free of an enzyme component that can remove proteinaceous material from the contact lens.

Preferred enteric polymeric components for use in the invention include anionic polymeric, that is, polymers bearing an overall negative charge when they are present in a neutral pH aqueous medium. Exemplary enteric polymeric components for use in the present invention include polymethacrylates, copolymers of acrylic acid or methacrylic acid with esters of acrylic acid or methacrylic acid (such as those products sold by Rohn Pharma under the trademark Eudragit^®) , cellulose acetate phthalate (CAP) , cellulose acetate trimellitate (CAT) , hydroxypropylmethyl cellulose phthalate (HPMCP) , polyvinyl acetate phthalate (PVAP) , and the like and mixtures thereof. In another broad aspect, methods for treating a contact lens are provided that employ the present compositions. Such methods comprise contacting the contact lens with a composition as described herein at conditions effective to remove proteinaceous material from the lens. When the composition includes an above- described at least one solid article, the method comprises contacting a contact lens with a liquid aqueous medium combined with the composition at conditions effective to remove proteinaceous deposit material from the contact lens. During the contacting, the liquid medium may be subjected to agitation, such as by shaking the lens vial containing the liquid medium and contact lens, so as to at least facilitate deposit material removal from the lens, for example, by physically dislodging the deposits from the lens. In one embodiment, after contacting, the lens is manually rubbed at conditions effective to remove further deposit material from the lens. The methods can further comprise rinsing the contact lens substantially free of a composition of the invention, along with any dislodged lens deposit material.

While not wishing to be bound to any particular theory of operation it is believed that the enteric polymeric component interacts with, for example, binds to, proteinaceous deposits, for example, such as deposits derived from lysozyme, on the contact lens, thereby removing the proteinaceous deposits from the lens surface and facilitating removal of other deposits on the lens. In more detail, the preferred negatively charged enteric polymeric component is believed to bind positively charged proteins, such as lysozyme, and, in so doing, at least facilitates removing proteinaceous deposit material from the contact lens. Thus, the present invention permits a user to remove deposit material from the contact lens substantially without detrimentally affecting the lens, such as by scratching or abrading the lens surface.

Accordingly, compositions and methods of the invention can be used to clean contact lenses when provided in cleaning kits as solid articles, for example, tablets, or in liquid aqueous media, such as solutions. For instance, the compositions can substitute for weekly protein removal tablets. Alternatively, compositions, such as one or more solid articles, in accordance with the present inventions which are free of cleaning enzyme components can be used to encapsulate a disinfectant destroying component, such as catalase, thereby affording non- enzymatic protein removal and delayed release of the destroying component in one unit. The compositions can be used in combination with disinfectants, detergents, lubricants, wearability components, other contact lens care components, and the like, for example, in aqueous solutions therefore. A particularly attractive feature of the invention is that, in many instances, chemical disinfectants, such as hydrogen peroxide, chlorine dioxide and substantially non-oxidative disinfectants, can be in intimate contact with the protein-removing component of the composition without significant decomposition of either component. The present invention can afford both disinfecting and cleaning of contact lenses in a single composition/step.

These and other aspects and advantages of the present invention will be apparent from the following detailed description and claims.

Detailed Description of the Invention

The present invention is useful for treating, for example, cleaning, contact lenses. Any contact lens, for example, conventional hard contact lenses, rigid gas permeable contact lenses and soft contact lenses, can be treated in accordance with the present invention.

In one embodiment, the present compositions comprise a liquid aqueous medium, and an enteric polymeric component in an amount effective to remove proteinaceous deposit material from a contact lens contacted with the composition. The enteric polymeric component is soluble in the liquid aqueous medium, and preferably is ophthalmically acceptable in the liquid aqueous medium. The composition can be substantially free of other components, such as disinfectant components, for example, oxidative disinfectant components. In a particularly useful embodiment, the present compositions are substantially free of cleaning enzyme components, such as the proteolytic enzymes conventionally used to remove proteinaceous deposit material from contact lenses.

A liquid aqueous medium or other material is "ophthalmically acceptable" when it is compatible with ocular tissue, that is, it does not cause significant or undue detrimental effects when brought into contact with ocular tissue. Preferably, the ophthalmically acceptable material is also compatible with other components of the present compositions. Preferred enteric polymeric components for use in the present invention include anionic polymers, that is, those polymers which are negatively charged at neutral pH. Many of these anionic enteric polymeric components are substantially insoluble at low pH, for example, below a pH of about 4 or about 5, but are soluble at substantially neutral or alkaline pH, such as a pH of about 6 to about 10.

Examples of suitable enteric polymeric components for use in the present invention include polymethacrylates, copolymers of acrylic acid and esters (such as alkyl esters) of acrylic acid; copolymers of methacrylic acid and esters (such as alkyl esters) of methacrylic acid; copolymers of acrylic acid and esters of methacrylic acid; copolymers of methacrylic acid and esters of acrylic acid; cellulose acetate phthalate (CAP) ,* cellulose acetate trimellitate (CAT) ,* hydroxypropylmethyl cellulose phthalate (HPMCP) ,* polyvinyl acetate phthalate (PVAP) ; and the like mixtures thereof. Particularly useful enteric polymeric components include certain products sold by Rohm Pharma under the trademark Eudragit^®, for example, the Eudragit L products and the Eudragit S products.

Certain of the aforementioned Eudragit products have been used as coatings for pharmaceuticals due to their property of being insoluble under gastric juice (acidic) conditions, but dissolving under intestinal fluid (basic) conditions. Both the L and S types of the Eudragit products are preferred for use in the present invention since both are anionic and are readily soluble at any ophthalmically acceptable pH in the range of about 6 to about 8 or about 10. Type L Eudragit products are characterized as being derived from or including about 50% methacrylic acid units and Type S Eudragit products are derived from or including about 30% methacrylic acid units. Particularly preferred enteric polymeric components are copolymers of methacrylic acid and ethyl acrylate, such as the copolymers present in the Eudragit L products, such as Eudragit L-30D and L100-55 products.

The amount of enteric polymeric component to be used in accordance with the present invention is such as to be effective to remove proteinaceous deposit material from a contact lens contacted with a liquid aqueous medium containing the enteric polymeric component in solubilized form. The specific amount of enteric polymeric component employed depends on a number of factors, for example, the specific enteric polymeric component and liquid aqueous medium being employed, the contact lens being cleaned, the amount and type of deposit material on the contact lens and the like factors. Excessive amounts of enteric polymeric components are to be avoided as being wasteful and since such excessive amounts may adversely affect the ophthalmic acceptability of ^■ the liquid aqueous medium containing the polymeric component. In a particularly useful embodiment, the amount of enteric polymeric component is such so that 10 ml of a liquid aqueous medium contains about 0.005% to about 0.1% or about 0.5% by weight of the enteric polymeric component.

In one embodiment, compositions in accordance with the present invention comprise at least one solid article, for example, a tablet, pill, pellet, or plurality of particles (for example, powder or granules) . The enteric polymeric component, preferably distributed throughout the at least one solid article, is present in an amount effective to remove proteinaceous material from a contact lens when the lens is contacted with a liquid aqueous medium containing the enteric polymeric component from at least one solid article in solubilized form. More preferably, the enteric polymeric component is distributed substantially uniformly throughout the at least one solid article. The solid article can be formed by compressing a mass of precursor material having substantially the same chemical makeup as the at least one solid article. In one embodiment, the release of the enteric polymeric component in the liquid aqueous medium can be delayed by the use of a delayed release or barrier component. Such delayed release of the enteric polymeric component is useful in applications in which the enteric polymeric component is incompatible with one or more other components in the liquid aqueous medium. For example, certain substantially non- oxidative disinfectant components, such as hexamethylene biguanides and their polymers, used to disinfect contact lenses may react with, and/or become deactivated by, the negatively charged enteric polymeric component. Therefore, in order to avoid this and to obtain both effective disinfecting and cleaning of the contact lens, the enteric polymeric component is provided in a delayed release form. The release of the enteric polymeric component is delayed a sufficient period of time so that the incompatible component, for example, the substantially non-oxidative disinfectant component, can perform its function, for example, disinfect the contact lens, before the enteric polymeric component is released in the liquid medium to perform its function.

The barrier component may be provided by coating a core tablet, pill, granules or other particle or particles or the like, containing the enteric polymeric component with a slow dissolving coating material, which may ultimately be completely or only partially soluble in the liquid aqueous medium. The delayed exposure form of the enteric polymeric component is preferably such that substantially no effective exposure of the enteric polymeric component to the liquid aqueous medium occurs during the delay period followed by rapid and substantially complete exposure of the enteric polymeric component at the end of or after the delay period.

Barrier components suitable as either coatings or as matrices, include water soluble vinyl polymers, such as polyvinylpyrollidone, polyvinylalcohol and polyethyleneglycol; water soluble proteins; polysaccharide and cellulose derivatives, such as methyl cellulose, hydroxypropylmethyl cellulose, sodium carboxymethyl cellulose; alginic acid and its salts and other derivatives; and the like and mixtures thereof. Although multi-layered (including core and coating layers) tablets or pills are preferred, the delayed release form of the present compositions can be present in any other suitable item or items, such as masses of powders, granules and the like. Delayed release technology which may be employed to provide for delayed exposure of the enteric polymeric component is well known in the art as exemplified by the text Controlled Drug Delivery, 2nd Ed., Joseph R. Robinson & Vincent H.L. Lee, Eds., Marcel Dekker, Inc., New York, 1987.

The amount of barrier components used is not critical in the present invention provided that such barrier component functions as described herein. The barrier component or components may suitably be present in the range of about 1% or about 5% to about 1000% or more, based on the weight of the enteric polymeric component.

The present solid compositions may be produced using any one of many suitable methods, a number of which are conventional and well known in the art. The production method chosen depends, in large measure, on the desired form of the composition. For example, the at least one item can be molded or cut or otherwise shaped into the desired form. The present compositions may comprise a disinfectant component. In one embodiment, the disinfectant component is present in the liquid aqueous medium in a substantially constant amount, that is, the concentration of the disinfectant component does not vary substantially with time, such as if it were incompatible with other components or were in the process of being destroyed, such as in the case of hydrogen peroxide in the presence of catalase or other hydrogen peroxide destroying components. The amount of the disinfectant component present in the liquid aqueous medium is effective to disinfect a contact lens placed in contact with the composition. When a disinfecting component is desired to be included in an instant composition, it may be an oxidative disinfectant component or a substantially non-oxidative disinfectant component. Oxidative disinfectant components act to reduce the microbial load on a contact lens by oxidatively attacking the microbes. The oxidative disinfectant suitable for use in the present invention is preferably selected from hydrogen peroxide, chlorine dioxide, metal, such as alkali metal, peroxy salts, such as peroxymonosulfate salts, and the like and mixtures thereof.

As used herein, substantially non-oxidative disinfectant components include effectively non- oxidative organic chemicals which derive their antimicrobial activity through a chemical or physiochemical interaction with the microbes or microorganisms. Suitable non-oxidative disinfectant components are those generally employed in ophthalmic applications and include, but are not limited to, quaternary ammonium salts used in ophthalmic applications such as poly[dimethylimino-2-butene-l, - diyl] chloride, alpha- [4-tris (2-hydroxyethyl) ammonium] -dichloride (chemical registry number 75345- 27-6, available under the trademark Polyquarternium 1^® from Onyx Corporation) , benzalkonium halides, and biguanides such as salts of alexidine, alexidine-free base, salts of chlorhexidine, hexamethylene biguanides and their polymers, antimicrobial polypeptides, and the like and mixtures thereof. A particularly useful substantially non-oxidative disinfectant component is selected from tromethamine (2-amino-2-hydroxymethyl-l, 3 propanediol) and its ophthalmically acceptable salts alone or in combination with a microbicide component selected from polyhexamethylene biguanide (PHMB) , N- alkyl-2-pyrsolidone, chlorhxidine, Polyquarternium-1, hexetidine, bronopol, alexidine, very low concentrations of peroxide, ophthalmically acceptable salts thereof and mixtures thereof.

The salts of alexidine and chlorhexidine can be either organic or inorganic and are typically disinfecting gluconates, nitrates, acetates, phosphates, sulphates, halides and ' the like. Generally, the hexamethylene biguanide polymers, also referred to as polyaminopropyl biguanide (PAPB) , have molecular weights of up to about 100,000. Such compounds are known and are disclosed in U.S. Patent No. 4,758,595.

The substantially non-oxidative disinfectant components useful in the present invention are preferably present in the liquid aqueous medium in concentrations in the range of about 0.00001% to about

2% (w/v) .

More preferably, the substantially non-oxidative disinfectant component is present in the liquid aqueous medium at an ophthalmically acceptable or safe concentration such that the user can remove the disinfected lens from the liquid aqueous medium and thereafter directly place the lens in the eye of safe and comfortable wear.

When a contact lens is desired to be disinfected by a disinfectant component, an amount of disinfectant effective to disinfect the lens is used. Preferably, such an effective amount of the disinfectant reduces the microbial burden on the contact lens by one log order, in three hours. More preferably, an effective amount of the disinfectant reduces the microbial load by one log order in one hour. Particularly preferred are disinfectant concentrations that reduce the microbial loan by one log order in ten minutes or less. The disinfectant component in accordance with the present invention is preferably provided in the liquid aqueous medium, and is more preferably soluble in the liquid aqueous medium. As an alternate to the use of chemical disinfectants, the contact lens may be thermally disinfected, for example, while in a liquid aqueous medium containing an enteric polymeric component, as described herein. Subjecting a contact lens to elevated temperatures, for example, on the order of about 60°C to about 100°C, for a period of time, for example, on the order of about 0.3 hours to about 2 hours or more, is effective to disinfect the lens. The present compositions may further comprise effective amounts of one or more additional components, such as an additional cleaning component, for example, a detergent component, an enzyme component and the like; a conditioning component; a wetting component; a wearability component, a buffer component, a tonicity adjustor component; a chelating or sequestering agent, such as the disodium salt of ethylenediamine tetraacetic acid (EDTA) and the like and mixtures thereof . The additional component or components may be selected from materials which are known to be useful in contact lens care compositions and are included in amounts effective to provide the desired effect or benefit. When an additional component is included, it is preferably compatible under typical use and storage conditions with the other components of the composition. 'For instance, when a disinfectant component is provided the aforesaid additional component or components are preferably substantially stable in the presence of the disinfectant. Each of the additional components, if any, may be present in either the solid or liquid form of the present compositions. When the additional component or components are present as a solid, they can either be intimately admixed such as in a powder or compressed tablet or they can be substantially separated, although in the same particles, as in an encapsulated pellet or tablet . When the combination of enteric polymeric component and additional component or components is in liquid form, they are typically soluble in the liquid aqueous medium. One or both of the enteric polymeric component and the additional component or components can be in solid form until desired to be used, whereupon they can be dissolved in the liquid aqueous medium in order to effectively contact the surface of a contact lens.

When an additional cleaning component is included in the present compositions, the cleaning component should be present in an amount effective to at least facilitate removing debris from a contact lens. Exemplary cleaning components include detergents such as nonionic surfactants, for example, polysorbates (such as polysorbate 20-Tradename Tween 20) , ethylene oxide/ propylene oxide block copolymers, glycolic esters of fatty acids and the like, anionic surfactants, for example, alkyl ether sulfates and the like, and mixtures thereof. Cleaning enzymes may also be employed. A cleaning enzyme component can be provided in an amount effective to at least facilitate removing deposit material from the contact lens. Types of deposit material or debris which may be deposited on the lens include proteins, lipids, and carbohydrate-based or mucin-based debris. One or more types of debris may be present on a given lens.

The cleaning enzyme component employed may be selected from enzymes conventionally employed in the enzymatic cleaning of contact lenses. Among the preferred enzymes are proteases, lipases, and the like. Exemplary enzymes are described by Huth et al U.S. Patent No. 32,672 RE and Karageozian et al U.S. Patent No. 3,910,296, which disclosures are incorporated herein by reference.

Preferred proteolytic enzymes are those substantially free of sulfhydryl groups or disulfide bonds, the presence of which may react with active oxygen of the oxidative disinfectant, rendering the enzyme inactive. Metalloproteases, enzymes which contain a divalent metal ion, may also be used. Yet a more preferred group of proteolytic enzymes are the serine proteases, such as those derived from Bacillus and Streptomyces bacteria and Aspericrillus molds. Of this class of enzymes, still more preferred enzymes are those derived from alkaline proteases, generically referred to as subtilisin enzymes.

Other enzymes preferred for this application include pancreatin, trypsin, collaginase, keratinase, carboxylase, aminopeptidase, elastase, and aspergillopeptidase A and B, pronase E (from S_,_ crriseus) and dispase (from Bacillus polymvxa) .

In one embodiment, a liquid aqueous medium containing such a cleaning enzyme component preferably has sufficient enzyme to provide about 0.001 to about 3 Anson units of activity, more preferably about 0.01 to about 1 Anson units, per single lens treatment. However, higher or lower amounts may be used. Moreover, since enzyme activity is pH dependent, the preferred pH range for an enzyme can be determined by the skilled practitioner. A particularly noteworthy embodiment of the present compositions is substantially free of proteolytic enzyme. Such a formulation provides for effective contact lens cleaning without the need to rinse the lens after cleaning to free the lens of the enzyme.

Compositions of the invention can also include preservatives, stabilizers, color indicators of hydrogen peroxide decomposition, plasticizers, thickening agents and the like. Acceptable effective concentrations for these additional components in the compositions of the invention are readily apparent to the skilled practitioner.

The liquid aqueous medium used is selected to have no substantial deleterious effect on the lens being treated, or on the wearer of the treated lens. The liquid medium is constituted to permit, and even facilitate, the instant lens treatment or treatments. The liquid aqueous medium is preferably substantially isotonic or hypertonic (for example, slightly hypertonic) and/or ophthalmically acceptable. The liquid aqueous medium preferably includes an effective amount of a tonicity adjusting component to provide the liquid medium with the desired tonicity. The liquid aqueous medium of the present invention preferably includes a buffer component which is present in an amount effective to maintain the pH of the medium in the desired range. Such tonicity adjusting components and buffer components may be present in the liquid aqueous medium and/or may be introduced into the liquid aqueous medium. Among the suitable tonicity adjusting components that may be employed are those conventionally used in contact lens care products, such as various inorganic salts. Sodium chloride and the like are very useful tonicity adjusting components. Among the suitable buffer components or buffering agents that may be employed are those conventionally used in contact lens care products. The buffer salts are preferably alkali metal, alkaline earth metal, or ammonium salts. Particularly useful media are those derived from saline, e.g., a conventional saline solution, or buffered saline solution. In addition, the liquid aqueous media may include one or more other materials, for example, as described elsewhere herein, in amounts effective to treat the contact lens (for example, provide a beneficial property to the contact lens) contacted with such media. In the event an oxidative disinfectant component is employed, a disinfectant destroying component is preferably also employed. Any agent effective in destroying the oxidative disinfectant used can be employed as the disinfectant destroying component . Such a disinfectant destroying component should be used in an amount effective to destroy substantially all the oxidative disinfectant present in the liquid aqueous medium during a reasonable period of time. The disinfectant destroying component employed should have no undue detrimental effect on the contact lens or on a wearer's eye when the lens is placed therein. Particularly useful disinfectant destroying components include reducing agents, enzymes, such as peroxidases, for example, catalase, and mixtures thereof.

Exemplary reducing agents include those effective to chemically reduce hydrogen peroxide. Such reducing agents include thiosulfates, thiourea, sulfites, thioglycerol, N-acetylcysteine, formates, ascorbic acid, isoascorbic acid, glyoxylic acid and mixtures thereof. Especially preferred are alkali metal salts of the above compounds. Peroxidases, that is enzymes that promote the decomposition of hydrogen peroxide, can also be employed. A particularly preferred peroxidase is catalase. When catalase is employed as a disinfectant destroying component, a useful amount of catalase for a liquid aqueous medium containing about 3% (w/v) hydrogen peroxide is preferably about 10 to about 1000, more preferably about 20 to about 800, international units of catalase activity per milliliter of liquid aqueous medium.

If a disinfectant destroying component is employed, it may be provided in a delayed release form, for example, in one or more solid articles in combination with a delayed release or barrier component as described elsewhere herein. The release of the disinfectant destroying component is preferably delayed a sufficient time, for example, on the order of about 0.1 hour to about 2 hours or more, to allow the oxidative disinfectant component to disinfect a contact lens placed in the liquid aqueous medium containing the oxidative disinfectant component at substantially the same time the disinfectant destroying component is initially contacted with the liquid aqueous medium.

Methods for cleaning a contact lens using the herein described compositions are included within the scope of the invention. Such methods comprise contacting a contact lens with such a composition at conditions effective to remove proteinaceous deposit material from the contact lens.

The contacting temperature is preferred to be in the range of about 0°C to about 100°C, and more preferably in the range of about 10°C to about 60°C and still more preferably in the range of about 15°C to about 30°C. Contacting at or about ambient temperature is very convenient and useful. The contacting preferably occurs at or about atmospheric pressure. The contacting preferably occurs for a time in the range of about 5 minutes or about 1 hour to about 12 hours or more.

The contact lens can be contacted with the liquid aqueous medium by immersing the lens in the medium. During at least a portion of the contacting, the liquid medium containing the contact lens can be agitated, for example, by shaking the container containing the liquid aqueous medium and contact lens, to at least facilitate removal of deposit material from the lens. After such contacting step, the contact lens may be manually rubbed to remove further deposit material from the lens. The cleaning method can also include rinsing the lens substantially free of the liquid aqueous medium prior to returning the lens to a wearer's eye.

The following non-limiting examples illustrate certain aspects of the present invention. EXAMPLE 1 A tablet having the following composition is prepared by compressing a mixture of powders having the same chemical make-up using conventional compression tableting techniques:

Enteric Polymer⁽¹⁾ 10' mg

Anhydrous Sodium Carbonate 12 mg Tartaric Acid 15 mg

Filler 20 mg (1) An anionic polymer derived from methacrylic acid methyl ester sold by Rohm Pharma under the trademark Eudragit^® L 100-55. This material dissolves in liquid aqueous medium which have a pH in the range of about 6 to about 9 by forming soluble salts.

EXAMPLE 2 A tablet similar to that described in Example 1 is produced except that the tablet includes a delayed release coating having the following composition:

Hydroxypropylmethyl cellulose 5 mg

Triethylcitrate 0.8 mg (a plasticizer)

This coating is applied using conventional techniques.

EXAMPLE 3 A tablet prepared as in Example 1 is added to a vial containing 10 ml of a buffered saline solution and a proteinaceous deposit laden contact lens. The pH of the solution is 6.8. The tablet dissolves in the solution. The contact lens is maintained in this solution at room temperature overnight, that is for about 10 hours.

After this time, the lens is removed from the solution and is placed in the lens wearer's eye for safe and comfortable wear. It is found that a substantial portion of the proteinaceous deposits previously present on the lens has been removed. Alternatively, after the 10 hour period of time, the lens is removed from the solution and rinsed with an additional quantity of the buffered saline solution before being placed in the lens wearer's eye for safe and comfortable wear. Again, it is found that a substantial portion of the proteinaceous deposits previously present on the lens has been removed.

EXAMPLE 4

Example 3 is repeated except that after the 10 hour period of time the lens is removed from the solution, manually rubbed and rinsed with an additional quantity of the buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 5 Example 3 is repeated except that after 5 hours and at the end of the 10 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface) . After the 10 hour period of time, the lens is removed from the solution and rinsed with an additional quantity of the buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that substantially all of the proteinaceous deposits previously present on the lens have been removed. EXAMPLE 6 A solution having a pH of 6.8 is prepared by blending together the following components: Buffered Saline Solution 1000 ml Enteric Polymer ⁽³⁾ 1000 mg

(3) Similar in composition to that used in Example 1.

10 ml of this solution is introduced into a lens vial containing a proteinaceous deposit laden contact lens. The contact lens is maintained in this solution at room temperature overnight, that is for about 10 hours.

After this time, the lens is removed from the solution and is placed in the lens wearer's eye for safe and comfortable wear. It is found that a substantial portion of the proteinaceous deposits previously present on the lens has been removed. Alternatively, after the 10 hour period of time, the lens is removed from the solution and rinsed with a quantity of the buffered saline solution without the enteric polymer before being placed in the lens wearer's eye for safe and comfortable wear. Again, it is found that a substantial portion of the proteinaceous deposits previously present on the lens has been removed.

EXAMPLE 7

Example 6 is repeated except that after the 10 hour period of time the lens is removed from the solution, manually rubbed and rinsed with a quantity of the buffered saline solution without the enteric polymer. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that substantially all of the proteinaceous deposits previously present on the lens have been removed. EXAMPLE 8

Example 6 is repeated except that after 5 hours and at the end of the 10 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface) . After the 10 hour period of time, the lens is removed from the solution and rinsed with an additional quantity of the buffered saline solution without the enteric polymer. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 9 Example 6 is repeated except that the solution further includes an effective amount of a conventional detergent, such as polysorbate 20.

After the 10 hour period of time, the lens is removed from the solution and is placed in the lens wearer's eye for safe and comfortable wear. It is found that a substantial portion of the proteinaceous deposits previously present on the lens has been removed. Also, the lens has enhanced wettability (by the fluids in the eye) as a result of the detergent in the solution. Alternatively, after the 10 hour period of time, the lens is removed from the solution and rinsed with a quantity of the solution without the enteric polymer before being placed in the lens wearer's eye for safe and comfortable wear. Again, it is found that a substantial portion of the proteinaceous deposits previously present on the lens has been removed and that the lens has enhanced wettability (by the fluids in the eye) as a result of the detergent in the solution. EXAMPLE 10

Example 9 is repeated except that after the 10 hour period of time the lens is removed from the solution, manually rubbed and rinsed with a quantity of the solution without the enteric polymer. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that substantially all of the proteinaceous deposits previously present on the lens have been removed. Also, the lens has enhanced wettability (by the fluids in the eye) as a result of the detergent in_^ the solution.

EXAMPLE 11 Example 9 is repeated except that after 5 hours and at the end of the 10 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface) . After the 10 hour period of time, the lens is removed from the solution and rinsed with an additional quantity of the solution without the enteric polymer. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that substantially all of the proteinaceous deposits previously present on the lens have been removed. Also, the lens has enhanced wettability (by the fluids in the eye) as a result of the detergent in the solution.

EXAMPLE 12

A solution similar to that of Example 6 is prepared. This solution further includes 50 parts per million (ppm) by weight of a stabilized chlorine dioxide product sold by Bio-Cide International under the trademark Purogene^®.

10 ml of this solution is contacted with a quantity of palladium-containing particles effective to form chlorine dioxide in the solution, which is then passed to a vial containing a proteinaceous deposit laden contact lens. This lens is maintained in this solution at room temperature overnight, that is for about 10 hours.

After this time, the lens is removed from the solution and is placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 10 hours and that a substantial portion of the proteinaceous deposits previously present on the lens has been removed. Alternatively, after the 10 hour period of time, the lens is removed from the solution and rinsed with a quantity of buffered saline solution before being placed in the lens wearer's eye for safe and comfortable wear. Again, it is found that the lens is disinfected during the 10 hours and that a substantial portion of the proteinaceous deposits previously present on the lens has been removed.

EXAMPLE 13 Example 12 is repeated except that after the 10 hour period of time the lens is removed from the solution, manually rubbed and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 10 hours and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 14

Example 12 is repeated except that after 5 hours and at the end of the 10 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface) . After the 10 hour period of time, the lens is removed from the solution and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 10 hours and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 15 A solution similar to that of Example 6 is prepared. This solution further includes 0.01% by weight of a non-oxidative antimicrobial component, such as the agent sold by Onyx Corporation under the trademark Polyquaternium-1. 10 ml of this solution is introduced into a vial containing a proteinaceous deposit laden contact lens. The lens is maintained in this solution at room temperature overnight, that is for about 10 hours.

EXAMPLE 16 Example 15 is repeated except that after the 10 hour period of time, the lens is removed from the solution, manually rubbed and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 10 hours and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 17

Example 15 is repeated except that after 5 hours and at the end of the 10 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface) . After the 10 hour period of time, the lens is removed from the solution and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 10 hours and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 18 A buffered saline solution having a pH of 6.8 and containing 0.01% by weight of polyhexamethylene biquanide is prepared.

10 ml of this solution is introduced into a lens vial containing a proteinaceous deposit laden contact lens. At substantially the same time, a tablet similar to that prepared in Example 2 is added to the solution in the vial. The lens is maintained in the solution at room temperature for about 12 hours.

After this time, the lens is removed from the solution and is placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 12 hours and that a substantial portion of the proteinaceous deposits previously present on the lens has been removed. Alternatively, after the 12 hour period of time, the lens is removed from the solution and rinsed with a quantity of buffered saline solution before being placed in the lens wearer's eye for safe and comfortable wear. Again, it is found that the lens is disinfected during the 12 hours and that a substantial portion of the proteinaceous deposits previously present on the lens has been removed.

EXAMPLE 19 Example 18 is repeated except that after the 12 hour period of time, the lens is removed from the solution, manually rubbed and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 12 hours and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 20 Example 18 is repeated except that after 8 hours and at the end of the 12 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface. After the 12 hour period of time, the lens is removed from the solution and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 12 hours and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 21

A substantially isotonic aqueous medium including

0.1% by weight of the enteric polymer described in

Example 1 and 3% (w/v) of hydrogen peroxide is prepared for testing. This aqueous medium is buffered to a pH of 6.1.

10 ml of this medium is introduced into a vial containing a proteinaceous deposit laden contact lens. This lens is maintained in this medium at room temperature for about 1 hour. During this time, the hydrogen peroxide concentration of the medium remains substantially constant. After this period of time, sufficient catalase is introduced into the medium to cause the destruction of all the hydrogen peroxide present, and the pH is adjusted to and maintained at 6.8. The lens is maintained in this adjusted medium overnight, that is for about 10 hours. After this 10 hour period of time, the lens is removed from the medium and is placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected and that a substantial portion of the proteinaceous deposits previously present on the lens has been removed. Alternatively, after the 10 hour period of time, the lens is removed from the medium and rinsed with a quantity of buffered saline solution before being placed in the lens wearer's eye for safe and comfortable wear. Again, it is found that the lens is disinfected and that a substantial portion of the proteinaceous deposits previously present on the lens has been removed.

EXAMPLE 22

Example 21 is repeated except that after the 10 hour period of time the lens is removed from the medium, manually rubbed and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 23

Example 21 is repeated except that after 5 hours and at the end of the 10 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface) . After the 10 hour period of time, the lens is removed from the medium and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 24 A two (2) layer tablet, having a core tablet surrounded by a coating, is prepared for testing. The core tablet and coating have the following compositions :

CORE TABLET

Crystalline catalase⁽⁴⁾ 1.5 mg

Sodium chloride 89.4 mg Dibasic sodium phosphate (anhydrous) 12.0 mg

Monobasic sodium phosphate monohydrate 1.0 mg

Polyethylene glycol (molecular weight about 3350) 1.0 mg Enteric polymer⁽⁵⁾ 10.0 mg

COATING

Hydroxyppropylmethyl cellulose phthalate 5.0 mg

(4) The tablet contains about 5200 units of catalase activity.

(5) Similar in composition to that used in Example 1.

10 ml of an aqueous solution containing 3% (w/v) of hydrogen peroxide is introduced into a vial containing a proteinaceous deposit laden contact lens. At substantially the same time, the above-noted tablet is introduced into the vial. After about 30 minutes, the tablet dissolves in the solution. The lens is maintained in this solution at room temperature for about 10 hours.

EXAMPLE 25 Example 24 is repeated except that after the 10 hour period of time the lens is removed from the solution, manually rubbed and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the lens is disinfected during the 10 hours and that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 26

Example 24 is repeated except that after 5 hours and at the end of the 10 hour period of time the vial is shook (which facilitates dislodging deposit material from the lens surface. After the 10 hour period of time, the lens is removed from the solution and rinsed with a buffered saline solution. The lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that substantially all of the proteinaceous deposits previously present on the lens have been removed.

EXAMPLE 27 A quantity, 1000 mg, of the enteric polymer used in Example 1 is combined with and solubilized in 1000 ml of a conventional rigid contact lens care solution, such as the product sold by Allergan, Inc. under the trademark Wet-N-Soak Plus™.

2 ml of the resulting solution is introduced into a lens storage case containing a proteinaceous deposit laden rigid contact lens. The rigid contact lens is maintained in this solution at room temperature overnight, that is for about 10 hours.

After this time, the rigid lens is removed from the solution and is placed in the lens wearer's eye for safe and comfortable wear. It is found that the rigid lens is provided with the benefits normally obtained by soaking the lens in the above-noted rigid contact lens care solution and, in addition, a substantial portion of the proteinaceous deposits previously present on the lens has been removed. Alternatively, after the 10 hour period of time, the rigid lens is removed from the solution and rinsed with a quantity of above-noted rigid contact lens care solution without the enteric polymer, before being placed in the lens wearer's eye for safe and comfortable wear. Again, it is found that the rigid lens is provided with the benefits normally obtained by soaking the lens in the above-noted rigid contact lens care solution and, in addition, a substantial portion of the proteinaceous deposits previously present on the lens has been removed. EXAMPLE 28

Example 27 is repeated except that after the 10 hour period of time, the lens is removed from the solution, manually rubbed and rinsed with a quantity of the above-noted rigid contact lens care solution without the enteric polymer. The rigid lens is then placed in the lens wearer's eye for safe and comfortable wear. It is found that the rigid lens is provided with the benefits normally obtained by soaking the lens in the above-noted rigid contact lens care solution and, in addition, that substantially all of the proteinaceous deposits previously present on the lens have been removed.

While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto, and that it can be variously practiced within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A composition effective for removing deposit material from a contact lens comprising: a liquid aqueous medium; a disinfectant component present in said liquid aqueous medium in a substantially constant amount effective to disinfect a contact lens contacted with said composition; and an enteric polymeric component present in said liquid aqueous medium in an amount effective to remove proteinaceous deposit material from a contact lens contacted with said composition.

2. The composition of claim 1 wherein said enteric polymeric component is anionic and is soluble in said liquid aqueous medium.

3. The composition of claim 1 wherein said enteric polymeric component is selected from the group consisting of polymethacrylates, copolymers of acrylic acid and esters of acrylic acid, copolymers of methacrylic acid and esters of methacrylic acid, copolymers of acrylic acid and esters of methacrylic acid, copolymers of methacrylic acid and esters of acrylic acid, cellulose acetate phthalate, cellulose acetate trimellitate, hydroxypropylmethyl cellulose phthalate, polyvinyl acetate phthalate and mixtures thereof.

4. The composition of claim 1 wherein said disinfectant component is substantially non-oxidative.

5. A composition effective for removing deposit material from a contact lens comprising: a liquid aqueous medium adapted to contact a contact lens in cleaning the contact lens and being substantially free of an oxidative disinfectant component prior to said contacting; and an enteric polymeric component present in said liquid aqueous medium in an amount effective to remove proteinaceous deposit material from a contact lens contacted with said composition.

6. The composition of claim 5 wherein said enteric polymeric component is anionic and is soluble in said liquid aqueous medium.

7. The composition of claim 5 wherein said enteric polymeric component is selected from the group consisting of polymethacrylates, copolymers of acrylic acid and esters of acrylic acid, copolymers of methacrylic acid and esters of methacrylic acid, copolymers of acrylic acid and esters of methacrylic acid, copolymers of methacrylic acid and esters of acrylic acid, cellulose acetate phthalate, cellulose acetate trimellitate, hydroxpropylmethyl cellulose phthalate, polyvinyl acetate phthalate and mixtures thereof.

8. The composition of claim 5 which is substantially free of an enzyme component effective to remove proteinaceous deposit material from a contact lens contacted with said composition.

9. The composition of claim 5 which further comprises a substantially non-oxidative disinfectant component present in said liquid aqueous medium in an amount effective to disinfect a contact lens contacted with said composition.

10. A composition comprising at least one solid article including an enteric polymeric component which is soluble in a liquid aqueous medium used to contact a contact lens in cleaning the contact lens and which is distributed throughout said at least one solid article in an amount effective to remove proteinaceous deposit material from the contact lens contacted with a liquid medium containing said enteric polymeric component in soluble form.

11. The composition of claim 10 wherein said enteric polymeric component is distributed substantially uniformly throughout said at least one solid article.

12. The composition of claim 10 wherein said at least one solid article is formed by compressing a mass of precursor material having substantially the same chemical makeup as said at least one solid article.

13. The composition of claim 10 wherein said enteric polymeric component is anionic.

14. The composition of claim 10 wherein said enteric polymeric component is selected from the group consisting of polymethacrylates, copolymers of acrylic acid and esters of acrylic acid, copolymers of methacrylic acid and esters of methacrylic acid, copolymers of acrylic acid and esters of methacrylic acid, copolymers of methacrylic acid and esters of acrylic acid, cellulose acetate phthalate, cellulose acetate trimellitate, hydroxypropylmethyl cellulose phthalate, polyvinyl acetate phthalate and mixtures thereof.

15. The composition of claim 10 which is substantially free of an enzyme component effective to remove proteinaceous deposit material from a contact lens placed in said composition

16. The composition of claim 10 which further comprises a barrier component in an amount effective to delay the release of said enteric polymeric component in a liquid medium into which said composition is introduced.

17. A method for cleaning a contact lens comprising contacting a proteinaceous deposit material- containing contact lens with the composition of claim 1 at conditions effective to remove proteinaceous deposit material from said contact lens.

18. A method for cleaning a contact lens comprising contacting a proteinaceous deposit material- containing contact lens with the composition of claim 5 at conditions effective to remove proteinaceous material from said proteinaceous deposit material- containing contact lens.

19. A method for cleaning a contact lens comprising contacting a proteinaceous deposit material- containing contact lens with a liquid aqueous medium combined with the composition of claim 10 at conditions effective to remove proteinaceous deposit material from said proteinaceous deposit material-containing contact lens.

20. A method for cleaning a contact lens comprising contacting a proteinaceous deposit material- containing contact lens with a composition comprising a liquid aqueous medium and an enteric polymeric component present in a solubilized form in said liquid aqueous medium in an amount effective to remove proteinaceous deposit material from a contact lens contacting with said composition, said contacting occurring at conditions effective to remove proteinaceous deposit material from said proteinaceous deposit-containing contact lens.

21. The method of claim 20 wherein said liquid aqueous medium is agitated during at least a portion of said contacting sufficiently to at least facilitate the removal of proteinaceous deposit material from said proteinaceous deposit material-containing contact lens.

22. The method of claim 20 which further comprises manually rubbing said proteinaceous deposit- containing contact lens after said contacting at conditions effective to remove proteineous deposit material from said proteinaceous deposit material- containing contact lens.