BACKGROUND OF THE INVENTION This invention relates to compositions for treating contact lenses, especially rigid, gas permeable contact lenses.

The surfaces of contact lenses must have a certain degree of hydrophilicity to be wet by tears. Tear wettability is in turn necessary to provide the lens wearer with comfort and good vision.

One way to impart wettability to contact lens surfaces is to add hydrophilic monomers to the mixture of comonomers used to form the contact lens material. However, the relative amount of hydrophilic monomer added affects physical properties other than wettability. For example, the hydrophilic monomer content of rigid gas permeable lens materials is much less than that of soft, hydrogel lenses. The rigid lenses accordingly contain only a few percent water of hydration whereas soft lenses contain amounts varying from 10 to 90 %. Thus, while hydrophilic monomer addition does increase wettability, the technique is limited by the influence that it has on other properties.

Another way to impart wettability to lens surfaces is to modify the surface after polymerization. For example, surface coatings of hydrophilic polymers have been grafted onto the surface. Plasma treatment has also been used to increase the hydrophilicity of hydrophobic surfaces. Although effective, methods such as these are often expensive (requiring complicated and difficult manufacturing procedures) and impermanent.

Water soluble polymers in lens care solutions have also been used to enhance the wettability of lens surfaces. Use of wetting polymers in this way provides a "cushion" between the lens and the eye which is equated with increased wettability as wearer comfort and tolerance. However, a common drawback with this approach is that the cushion layer dissipates rapidly, since there is little specific interaction between the polymer and the lens surface.

United States Patent Nos. 4,168,112 and 4,321,261 disclose a method to overcome this drawback by immersing the lens in a solution of an oppositely charged ionic polymer to form a thin polyelectrolyte complex on the lens surface. The complex increases the hydrophilic character of the surface for a greater period of time relative to an untreated surface. Of particular interest are cellulosic polymers bearing a cationic charge, said polymers forming a strongly adhered hydrophilic layer on the contact lens surface.

These polymers have proven to be exceptional components for wetting, soaking, and lubricating solutions.

Cationic surfactants greatly lower the surface tension of water and will accumulate on surfaces which have hydrophobic character. However, cationic surfactants are often not biocompatible with the eye. Some (i.e., benzalkonium chloride) are known to cause severe ocular reactions.

SUMMARY OF THE INVENTION The invention provides aqueous compositions for treating contact lenses comprising a quaternary nitrogen-containing ethoxylated alkyl glucoside.

Additionally, the invention relates to methods employing the compositions.

DETAILED DESCRIPTION OF THE INVENTION Representative quaternary nitrogen-containing ethoxylated alkyl glucosides useful in the practice of this invention are represented by Formula (I) :

wherein:

R ¹ is alkyl, preferably C^-Cie alkyl; the average sum of w, x, y, and z per mole of compound is within the range of about 4 to about 200, and preferably within the range of about 4 to about 20; n is 0 or 1; and

R ² , R ³ , R ⁴ , and R ⁵ are individually hydrogen or quaternary nitrogen-containing groups; provided that at least one R ² , R ³ , R ⁴ , or R ⁵ is a quaternary nitrogen-containing group and that at least one R ² , R ³ , R ⁴ , or R ⁵ is hydrogen.

Representative quaternary nitrogen-containing groups for R ² , R ³ , R ⁴ , or R ⁵ are represented by Formula

(II):

wherein R ⁶ is C ₁ - ₄ hydroxyalkylene; R ⁷ , R ⁸ , and R ⁹ are individually or combined as C!_ ₁₆ alkyl; and X is an anion, preferably a halide.

Especially preferred compounds of Formula (I) include compounds wherein R ¹ is methyl, each of R ² , R and R ⁴ is hydrogen, and R ⁵ is a quaternary nitrogen- containing group of Formula (II) .

The quaternary nitrogen-containing ethoxylated glucosides are commercially available or can be prepared by methods known in the art, such as the

ethods described in U.S. Patent No. 5,138,043 (Polovsky et al.).

An especially preferred material is quaternary nitrogen-containing ethoxylated glucose derivatives available under the CTFA (Cosmetic, Toiletry, and Fragrance Association) designation lauryl methyl gluceth-10 hydroxypropyldimonium chloride, including the product commercially available under the tradename Glucquat-100* (Amerchol Corp., Edison, New Jersey) . G UCQUAT-100 consists of a 10-mole ethoxylate of methyl glucoside and an ether-linked quaternized structure.

Applicants have found that the compositions of this invention are very effective at wetting the surfaces of contact lenses, especially rigid, gas permeable (RGP) contact lenses. The quaternary nitrogen-containing ethoxylated alkyl glucosides contain, in one portion of the molecule, a hydrophilic polyethoxylated alkyl glucoside derivative, and on another portion, a cationic, hydrophobic moiety attached to an ammonium ion. Due to the presence of the cationic moiety, the material can associate with negatively charged lens surfaces, whereby the hydrophilic moiety extends from the lens surface to maintain moisture on the surface. Additionally, this interaction with the lens imparts a "cushioning" effect to the lens surface to increase wearing comfort of lenses treated with the compositions.

The quaternary nitrogen-containing ethoxylated alkyl glucoside may be employed in the compositions at about 0.001 to about 10 weight percent of the composition, preferably at about 0.001 to about 5 weight percent, with about 0.005 to about 2 weight percent being especially preferred.

Typical compositions include buffering agents for buffering or adjusting pH of the composition, and/or tonicity adjusting agents for adjusting the tonicity of the composition. Representative buffering agents include: alkali metal salts such as potassium or sodium carbonates, acetates, borates, phosphates, citrates and hydroxides; and weak acids such as acetic, boric and phosphoric acids. Representative tonicity adjusting agents include: sodium and potassium chloride, and those materials listed as buffering agents. The tonicity agents may be employed in an amount effective to adjust the osmotic value of the final composition to a desired value. Generally, the buffering agents and/or tonicity adjusting agents may be included up to about 10 weight percent.

According to preferred embodiments, an antimicrobial agent is included in the composition in an antimicrobially effective amount, i.e., an amount which is effective to at least inhibit growth of microorganisms in the composition. Preferably, the

composition can be used to disinfect a contact lens treated therewith. Various antimicrobial agents are known in the art as useful in contact lens solutions, including: chlorhexidine (l,l'-hexamethylene-bis[5-(p- chlorophenyl) biguanide]) or water soluble salts thereof, such as chlorhexidine gluconate; polyhexamethylene biguanide (a polymer of hexamethylene biguanide, also referred to as polya inopropyl biguanide) or water-soluble salts thereof, such as the polyhexamethylene biguanide hydrochloride available under the trade name Cosroocil CQ (ICI Americas Inc.); benzalkonium chloride; and polymeric quaternary ammonium salts. When present, the antimicrobial agent may be included at 0.00001 to about 5 weight percent, depending on the specific agent.

The compositions may further include a sequestering agent (or chelating agent) which can be present up to about 2.0 weight percent. Examples of preferred sequestering agents include ethylenediaminetetraacetic acid (EDTA) and its salts, with the disodium salt (disodium edetate) being especially preferred.

The quaternary nitrogen-containing ethoxylated alkyl glucoside is very effective at providing the compositions with the ability to wet surfaces of contact lenses treated therewith. If desired, the composition may include as necessary a supplemental

wetting agent. Representative wetting agents include: polyethylene oxide-containing materials; cellulosic materials such as cationic cellulosic polymers, hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and methylcellulose; polyvinyl alcohol; and polyvinyl pyrrolidone. Such additives, when present, may be used in a wide range of concentrations, generally about 0.1 to about 10 weight percent.

Contact lenses are treated with the compositions by contacting the lenses with the compositions. For example, a contact lens can be stored in the solution, or soaked in the solution, for sufficient time to wet the surfaces thereof. The treated lens can be inserted directly in the eye, or alternately, the lens can be rinsed. Alternately, drops of solution can be placed on the lens surface and the treated lens inserted in the eye. The specific lens care regimen used will depend on the other compounds present in the solution, as is well known in the art.

For compositions containing an antimicrobial agent, the a contact lens is preferably soaked in the composition for sufficient time to disinfect the lens and wet the surface thereof.

According to a further embodiment of the invention, the compositions may include at least one surface active agent having cleaning activity for

contact lens deposits in order to provide contact lens solutions useful for cleaning and wetting contact lenses. A wide variety of surface active agents are known in the art as a primary cleaning agent, including anionic, cationic, nonionic and amphoteric surface active agents. Representative surface active agents are included in the Examples, infra. The surface active agents having cleaning activity for contact lens deposits may be employed at about 0.001 to about 5 weight percent of the composition, preferably at about 0.005 to about 2 weight percent, with about 0.01 to about 0.1 weight percent being especially preferred.

The following examples further illustrate preferred embodiments of the invention.

Components used in the following Examples are listed below. The list includes (in each case, if available) a generic description of the component, the corresponding identification adopted by the Cosmetic, Toiletry, and Fragrance Association (CTFA) , and the tradename and source of the component used.

Alkylaryl polyether alcohol Octoxynol-9 (CTFA)

Triton X-100 ^# (Rohm and Haas Co., Inc. Philadelphia, Pennsylvania)

Cocamidopropyl Betaine (CTFA) Monateric CAB ^# (Mona Industries Inc., Paterson, New Jersey)

Lauroamphoglycinate Sodium Lauroamphoacetate (CTFA) Monateric LM-M30 ^# (Mona Industries Inc., Paterson, New Jersey)

Cocoamphocarboxyglycinate Disodium Cocoamphodiacetate (CTFA) Monateric CSH-32* (Mona Industries Inc. , Paterson, New Jersey)

Isostearoamphopropionate Sodium Isostearoamphopropionate (CTFA) Monateric ISA-35* (Mona Industries Inc. , Paterson, New Jersey)

Cocoamphopropy1sulfonate

Sodium Cocoamphohydroxypropylsulfonate

(CTFA)

Miranol CS ^# Cone. (Rhone-Poulenc Inc. ,

Cranbury, New Jersey)

Lauryl ester of sorbitol Polysorbate 20 (CTFA) Tween 20 (ICI Americas, Inc., Wilmington, Delaware)

Sodium Tridecyl Ether Sulfate Sodium Trideceth Sulfate (CTFA) SIPEX EST-30* (Rhone-Poulenc, Inc., Cranbury, New Jersey) .

Polyoxyethylene, Polyoxypropylene Block

Polymer

Poloxamer 235 (CTFA)

Pluronic P-85 ^# (BASF Corp. ,

Parsippany, New Jersey)

Modified Cellulose Polymer Hydroxyethylcellulose (CTFA) Natrosol 250MR* (Aqualon Co. , Wilmington, Delaware)

Modified Cellulose Polymer Hydroxypropylmethylcellulose (CTFA) Methocel E4M* (Dow Chemical, Midland, Michigan)

Cationic Ethoxylated Glucose Derivative Lauryl Methyl Gluceth-10 Hydroxypropyldimonium Chloride (CTFA) Glucquat-100* (Amerchol Corp., Edison, New Jersey)

Hydrolyzed Polyvinylacetate

Polyvinyl Alcohol (CTFA)

Vinol 107 (Air Products Chemicals,

Inc. ,

Allentown, Pennsylvania)

Polyoxyethylene, Polyoxypropylene Block

Polymer

Poloxamer 407 (CTFA)

Pluronic F-127* (BASF Corp. ,

Parsippany, New Jersey)

Ethoxylated glycerol derivative Glycereth-26 (CTFA) Liponic EG-1* (Lipo Chemicals, Inc., Paterson, New Jersey)

Ethoxylated glycerol derivative Glycereth-26 (CTFA) Ethosperse G26* (Lonza Inc. , Fairlawn, New Jersey)

Ethoxylated sorbitol derivative Sorbeth-20 (CTFA) Ethosperse SL-20* (Lonza Inc. , Fairlawn, New Jersey)

Ethoxylated glucose derivative Methyl Gluceth-20 (CTFA) Glucam E-20* (Amerchol Corp. , Edison, New Jersey)

Sample materials for surface analyses in the

Examples were prepared from standard contact lens blanks. Wafers with a diameter of 12.7mm and a thickness of 0.25mm were cut from the blanks and both surfaces polished to an optical finish using a polishing powder dispersed in deionized water.

Polished samples were rinsed thoroughly with deionized water and stored in a clean glass vial under deionized water until use.

Dynamic contact angle measurements were made with hydrated, polished wafers utilizing a Cahn Instruments DCA 322. Wafers were dipped in the test solution 7 times at an average rate of 225 microns per second. All tests were run at room temperature. A computer assisted mathematical analysis of the data yields a graph of contact angle plotted against the vertical position on the wafer. The average Advancing and Receding contact angles were obtained from the graph.

The surface tension of solution samples is determined with a Cahn Instruments DCA 322. Glass slides measuring 25mm X 30mm X 0.14mm are flame cleaned and then dipped into the test solution 7 times at an average rate of 225 microns per second. All tests were run at room temperature. A computer assisted mathematical analysis of the data yields a graph of force versus position on the glass slide. The surface tension is obtained from this graph.

EXAMPLE 1 Solutions containing the following ingredients were prepared and passed through a 0.22 micron sterilizing filter in a clean room environment. The solutions were then packaged in sterile bottles.

Solυtion

The solutions described above were evaluated in-eye to assess the clinical impact of various concentrations of GLUCQUAT 100 in borate buffer. Eyes were examined using fluorescein instillation and biomicroscopy. Baselines on both eyes were established prior to instillation of any solutions. After instillation of two drops of test solution the eyes were examined again. The FDA classification of slit lamp findings was utilized to classify any corneal

staining. Additionally, the individuals were asked to comment on the comfort of the test solutions.

Solution A, the control produced no corneal staining and was perceived as "comfortable" by the test subjects. Solutions B through F produced the same results as the control, namely, no staining and no adverse effect on comfort. These results indicate that GLUCQUAT 100 is well tolerated in the ocular environment.

EXAMPLE 2 A fluorosilicone rigid gas permeable (RGP) contact lens material (BOSTON RXD*, Polymer Technology Corporation, Boston, Massachusetts) was cut into wafers and both sides were polished to an optical finish. Dynamic contact angles (DCA) were determined for the RGP material in various solutions described in TABLE 1. The DCA results are presented in TABLE 2.

TJ_ϋ_t_i

Solution

IASX_£___

S.T. Surface Tension (dynes/cm) Adv. Advancing contact angle in degrees Rec Receding contact angle in degrees

Adv-Rec Difference between advancing and receding contact angles

It is evident from the lowering of the surface tension that GLUCQUAT is very surface active, even at

low concentrations. At concentrations above 0.01% GLUCQUAT 100 dramatically lowers both the advancing and receding contact angles of the RGP material. The low hysteresis (Adv-Rec) suggests a strong adsorption of the GLUCQUAT on the surface of the lens material.

EXAMPLE 3

The formulations of this example are representative of conditioning solutions for contact lenses which provide disinfection and cushioning of the lens surface.

The hydroxypropyl methylcellulose (HPMC) , sodium chloride, potassium chloride, and disodium edetate were dissolved in deionized water, then autoclaved at 121*C for 30-40 minutes. The solution was then transferred to a clean room where the remaining ingredients, dissolved in deionized water, were added to the solution through a 0.22 micron filter. The final solution was mixed and dispensed to sterile bottles.

Solution

EXAMPLE 4

The solutions described in EXAMPLE 3 were evaluated on eye to assess the clinical performance of conditioning solutions containing GLUCQUAT 100 at

various concentrations. Clean BOSTON RXD lenses for two adapted RGP lens wearers were soaked in the solutions overnight. Each subject installed the lenses directly from the solution (no rinse step) and was examined immediately by a clinician who evaluated a number of parameters using a biomicroscope. The compiled results of the clinical evaluation of solutions A through E are presented below.

♦Tear Break-up Time

All solutions provided a conditioned lens surface which exhibited excellent ocular compatibility. The tear film wetted the entire surface of the lens and was even in nature. The quality of the tear film on the conditioned lens surface was such that very long tear break up times, greater than 15 seconds were observed.

EXAMPLE 5 The formulations of this example are representative of conditioning solutions containing a

polyethylene oxide-containing polymer for increased biocompatibility.

The HPMC, polyvinyl alcohol, sodium chloride, potassium chloride and disodium edetate were dissolved in deionized water, then autoclaved at 121*C for 30-40 minutes. The solution was then transferred to a clean room where the remaining ingredients, dissolved in deionized water, were added to the solution through a 0.22 micron filter. The final solution was mixed and dispensed to sterile bottles.

Solυtion

EJCAMPLE 6

The conditioning solutions described in EXAMPLE 5 were evaluated on eye to assess clinical performance. Clean BOSTON RXD lenses for two adapted RGP lens wearers were soaked in the solutions overnight. Each subject installed the lenses directly from the solution (no rinse step) and was examined immediately by a clinician who evaluated a number of parameters using a biomicroscope. The compiled results of the clinical evaluation of solutions A through D are presented below.

♦Tear Break-up Time

All solutions provided conditioned contact lenses surfaces which exhibited excellent ocular compatibility. The tear film evenly wetted the entire lens surface. The quality of the tear film was evidenced by the long tear break up time of greater than 15 seconds.

EXAMPLE 7

The formulations of this example are representative of conditioning solutions for contact lenses which provide disinfection and cushioning of the lens surface.

The HPMC, hydroxyethylcellulose (HEC) , polyvinyl alcohol, sodium chloride, potassium chloride, and disodium edetate were dissolved in deionized water, then autoclaved at 121*C for 30-40 minutes. The solution was then transferred to a clean room where the remaining ingredients, dissolved in deionized water, were added to the solution through a 0.22 micron filter. The final solution was mixed and dispensed to sterile bottles.

Solution

EXAMPLE 8

The solutions described in EXAMPLE 7 were evaluated on eye to assess the clinical performance. Clean BOSTON RXD lenses for two adapted RGP lens wearers were soaked in the solutions overnight. Each subject installed the lenses directly from the solution (no rinse step) and was examined immediately by a clinician who evaluated a number of parameters using a biomicroscope.

The compiled results of the clinical evaluation of solutions A through D are presented below.

♦Tear Break-up Time

All solutions produced conditioned contact lens surfaces which provided excellent ocular compatibilities. The tear film evenly wetted the entire lens surface. Tear break up times of greater than 15 seconds were observed indicating a tenacious tear film on the lens surface.

EXAMPLE 9

The formulations of this example are representative of multipurpose contact lens solutions which clean, disinfect and condition the surfaces of contact lenses in one step.

Solutions containing the following ingredients were prepared and passed through a 0.22 micron sterilizing filter in a clean room environment. The solutions were then packaged in sterile bottles.

Solution

EXAMPLE I The solutions described in EXAMPLE 9 were evaluated in-eye to assess the clinical impact of various concentrations of GLUCQUAT 100 and PLURONIC P-85 in borate buffer. Eyes were examined using fluorescein instillation and biomicroscopy at baseline and immediately after instillation of two drops of test solution. The FDA classification of slit lamp findings was utilized to classify any corneal staining. Additionally, the individuals were asked to comment on the comfort of the test solutions.

None of the solutions produced corneal staining and all were perceived as "comfortable" by the test subjects.

gXAMPK 11

The solutions of EXAMPLE 9 were evaluated to determine the cleaning efficacy in removing contact lens deposits during the soaking period.

BOSTON RXD lenses were worn by adapted RGP lens wearers for 12 to 16 hours. At that time lenses were removed from the eyes and placed in contact lens cases. The lenses were kept dry until use in the cleaning efficacy test.

The worn lenses were examined using a microscope at 20X magnification and the deposit pattern noted. A lens was then placed in a contact lens storage case and about 1 ml of the test solution was added to cover the lens completely with the fluid. The case was closed and allowed to stand at ambient conditions for 12 hours. At that time the lens was removed and rubbed between the forefinger and the thumb for about 20 seconds. The lens was then rinsed thoroughly with water and dried with compressed air. The dried lens was again examined at 2OX magnification to identify the extent of deposit removal. Results are shown below.

EXAMPLE 12

The formulations of this example are representative of multipurpose solutions which clean, disinfect, and condition the surfaces of contact lenses in one step.

Solutions containing the following ingredients were prepared and passed through a 0.22 micron sterilizing filter in a clean room environment. The solutions were then packaged in sterile bottles.

Solutions

EXAMPLE 13

The solutions described in EXAMPLE 12 were evaluated in-eye to assess the clinical impact of GLUCQUAT 100 with various non-ionic, anionic and amphoteric surfactants in borate buffer. Eyes were examined using fluorescein instillation and biomicroscopy at baseline and immediately after instillation of two drops of test solution. The FDA classification of slit lamp findings was utilized to classify any corneal staining. Additionally, the individuals were asked to comment on the comfort of the test solutions.

None of the solutions produced corneal staining and all were perceived as "comfortable" by the test subjects.

EXAMPLE 14 The solutions of EXAMPLE 12 were evaluated to determine their cleaning efficacy in removing contact lens deposits during the soaking period.

BOSTON RXD lenses were worn by adapted RGP lens wearers for 12 to 16 hours. At that time lenses were removed from the eyes and placed in contact lens cases. The lenses were kept dry until use in the cleaning efficacy test.

The worn lenses were examined using a microscope at 2OX magnification and the deposit pattern was noted. A lens was then placed in a contact lens storage case and about 1 ml of the test solution added to cover the lens completely with the fluid. The case was closed and allowed to stand at ambient conditions for 12 hours. At that time the lens was removed and rubbed between the forefinger and the thumb for about 20 seconds. The lens was then rinsed thoroughly with water and dried with compressed air. The dried lens was again examined at 2OX magnification to identify the extent of deposit removal.

Results are shown below.

EXAMPLE 15

The formulations of this example are representative of alcohol-containing cleaning solutions for contact lenses.

Cleaning solutions containing the following ingredients were prepared and bottled.

Solution

E MPLE 16

The solutions in EXAMPLE 15 were evaluated to determine the cleaning efficacy.

BOSTON RXD lenses were worn by adapted RGP lens wearers for 12 to 15 hours. At that time lenses were removed from the eyes and placed in contact lens cases. The lenses were kept dry until use in the cleaning efficacy test.

The worn lenses were examined using a microscope at 20X magnification and the deposit pattern noted. A lens was then placed in the palm of the hand and several drops of test solution were added. Using the forefinger, the lens was then rubbed in the palm of the hand for 20 seconds. A few more drops of test solution were added and the procedure repeated. The lens was then rinsed thoroughly with water and dried with compressed air. The dried lens was again examined at 2OX magnification to identify the extent of deposit removal.

-33-

Results are shown below. Each of the solutions was effective in removing deposits from worn contact lenses.