WO1998025650A2

WO1998025650A2 - Multi-purpose compositions for cleaning and disinfecting of lenses

Info

Publication number: WO1998025650A2
Application number: PCT/US1997/021579
Authority: WO
Inventors: Bahram Asgharian
Original assignee: Alcon Laboratories, Inc.
Priority date: 1996-12-13
Filing date: 1997-11-24
Publication date: 1998-06-18
Also published as: WO1998025650A3; EP0946208A2; CN1251533A; AU721951B2; KR20000057525A; JP2001508675A; AU5362498A; CA2274753A1; NZ336203A

Abstract

Two-compartment bottle assemblies useful in preparing multi-purpose compositions containing an ophthalmically acceptable enzyme and disinfectant, methods of preparing these compositions and methods involving the use of these compositions are disclosed for cleaning and disinfecting of contact lenses.

Description

MULTI-PURPOSE COMPOSITIONS AND METHODS OF USE IN CONTACT LENS CLEANING AND DISINFECTING SYSTEMS

Background of the Invention

The present invention relates to the field of contact lens cleaning and disinfecting. In

particular, this invention is directed to the provision of multi-purpose compositions and

methods for the preparation of these compositions. The invention is also directed to methods

of simultaneously cleaning and disinfecting contact lenses by using the enzyme and

disinfectant containing multi-purpose compositions of the present invention.

Various compositions and methods for cleaning contact lenses have been described in

the patent and scientific literature. Some of these methods have employed compositions

containing surfactants or enzymes to facilitate the cleaning of lenses. The first discussion of

the use of proteolytic enzymes to clean contact lenses was in an article by Lo, et al. in the

Journal of The American Optometric Association, volume 40, pages 1106-1109 (1969).

Methods of removing protein deposits from contact lenses by means of proteolytic enzymes

have been described in many publications since the initial article by Lo, et al., including U.S.

Patent No. 3,910,296 (Karageozian, et al.).

Numerous compositions and methods for disinfecting contact lenses have also been

described. Those methods may be generally characterized as involving the use of heat and/or

chemical agents. Representative chemical agents for this purpose include organic anti¬

microbials such as benzalkonium chloride and chlorhexidine, and inorganic anti-microbials

such as hydrogen peroxide and peroxide-generating compounds. U.S. Patents Nos. 4,407,791 and 4,525,346 (Stark) describe the use of polymeric quaternary ammonium compounds to

disinfect contact lenses and to preserve contact lens care products. U.S. Patents Nos. 4,758,595

and 4,836,986 (Ogunbiyi) describe the use of polymeric biguanides for the same purpose.

Various methods for enzymatic cleaning and disinfecting contact lenses at the same

time have been proposed. Methods involving the combined use of proteolytic enzymes and

peroxides to clean and disinfect contact lenses simultaneously, are described in U.S. Patent No.

Re 32,672 (Huth, et al.). A representative method of simultaneously cleaning and disinfecting

contact lenses involving the use of proteolytic enzymes and quaternary ammonium compounds

is described in Japanese Patent Publication 57-24526 (Boghosian, et al.). The combined use of

a biguanide (i.e., chlorhexidine) and liquid enzyme compositions to simultaneously clean and

disinfect contact lenses is described in Canadian Patent No. 1,150,907 (Ludwig, et al.).

Methods involving the combined use of dissolved proteolytic enzymes to clean and heat to

disinfect are described in U.S. Patent No. 4,614,549 (Ogunbiyi). The combined use of

proteolytic enzymes and polymeric biguanides or polymeric quaternary ammonium compounds

is described in copending, commonly assigned United States Patent Application Serial No.

08/156,043 and in corresponding European Patent Application Publication No. 0 456 467 A2

(Rosenthal, et al), as well as in U.S. Patent No. 5,096,607 (Mowrey-McKee, et al.).

The commercial viability of most prior enzymatic cleaning products has depended on

the use of stable enzyme tablets. More specifically, the use of solid enzymatic cleaning

compositions has been necessary to ensure stability of the enzymes prior to use. In order to use

such compositions, a separate packet containing a tablet must be opened, the tablet must be

placed in a separate vial containing a solution, and the tablet must be dissolved in order to

release the enzyme into the solution. This practice is usually performed only once a week due

to the cumbersome and tedious procedure and potential for irritation and toxicity. The use of concentrated liquid enzyme compositions in combination with a diluent to

clean contact lenses has been attempted in an effort to avoid the cumbersome use of enzyme

tablets. Those attempts, however, have been hampered by the fact that concentrated aqueous

liquid enzyme compositions are inherently unstable. When a proteolytic enzyme is placed in

an aqueous solution for an extended period (i.e., several months or more), the enzyme may lose

all or a substantial portion of its proteolytic activity. Steps can be taken to stabilize the

compositions. For example, stabilizing agents can protect enzymes from chemical instability

problems during storage in an aqueous liquid, by placing the enzymes in a dormant physical

conformation. However, the use of liquid enzyme compositions, as with the use of enzyme

tablet compositions described above, still requires a separate, additional mixing step each time

the lens is to be simultaneously cleaned and disinfected. Furthermore, since the amount of

liquid enzyme composition placed in a diluting composition is controlled by the user, user error

may result in too much or too little of the concentrate being dispensed in the diluting solution.

The following patents may be referred to for further background concerning prior

attempts to stabilize concentrated liquid enzyme formulations: U.S. Patents Nos. 4,462,922

(Boskamp); 4,537,706 (Severson); and 5,089,163 (Aronson). These patents describe detergent

compositions containing enzymes. U.S. Patent No. 5,281,277 (Nakagawa) and Japanese Kokai

Patent Applications Nos. 92-370197; 92-143718; and 92-243215 describe liquid enzyme

compositions for treating contact lenses.

A number of multi-purpose compositions for cleaning, disinfecting and storing contact

lenses are commercially available. The main cleaning ingredients of these products generally

comprise surfactants. Soft contact lenses become soiled by collecting various debris and also

by accumulated protein deposition on the lens surface. Failure to remove the protein deposits

results in opacification of the lens and lens spoilage. While surfactants are used to remove debris from the lens, they are not very efficacious in removing protein deposits. Proteolytic

agents, in contrast, are very effective in removing protein deposits that form on the lens over

time. Thus, cleaning regimens using multi-purpose compositions comprising surfactants still

require the additional step of employing a proteolytic agent to remove protein deposits.

The use of a single enzyme containing multi-purpose solution for the cleaning and

disinfecting of contact lenses has been proposed in U.S. Patent No. 5,409,546 (Nakagawa et

al.) and European Patent Application No. 0 646, 641 (Nakayawa et al.). These patents disclose

compositions wherein the enzyme is in a dilute concentration, and the compositions, therefore,

require no dilution step prior to use. These compositions, however, provide limited stability of

the enzyme (1 or 2 months at room temperature). The limited shelf-life of these compositions

generally does not permit their commercialization.

Brief Description of the Drawings

FIG. 1 is a perspective view of a preferred embodiment of the invention.

FIG. 2 is a elevation view of a preferred embodiment of the invention.

FIG. 3 is an exploded elevation view of a preferred embodiment of the invention.

FIG. 4 is an exploded cross-section view of a preferred embodiment of the invention

about line 4-4 of FIG. 3.

FIG. 5 is a cross-section view about line 5-5 of FIG 2 of a preferred embodiment of the invention.

FIG. 6 is a cross-section view about line 5-5 of FIG. 2 of a preferred embodiment of the

invention, illustrating the downward rotation of a cap/plunger assembly, the breaking of a

membrane, and the egress of an enzyme composition. FIG. 7 is a top plan view of a housing of the invention.

FIG. 8 is a bottom plan view of a cap and collar of the invention.

Summary of the Invention

The present invention is directed to two-part systems which provide for the generation

of multi-purpose compositions useful in the simultaneous cleaning and disinfecting of contact

lenses. The present invention is also directed to methods of simultaneously cleaning and

disinfecting contact lenses using the two-part system. The two-part system comprises an

enzyme cleaning composition, an aqueous composition and one or more anti-microbial

agent(s). The enzyme composition provides a concentrated amount of an enzyme. The

aqueous composition provides a diluting solution. The anti-microbial agent is contained in

either the enzyme composition or the aqueous composition. The two-part system is initialized

for use by admixing the enzyme composition with the aqueous composition.

The two-part system uses a two-compartment device capable of keeping separate an

enzyme composition and a diluting composition prior to their initial use. One feature of this

device is that it combines the separate components in a single bottle assembly. This feature has

the advantage over prior art systems which have required the more difficult, tedious and

cumbersome use of separate containers. Related to this feature is the fact that the enzyme is

added only once to the disinfecting composition, and the resulting multi-purpose composition

can then be used many times over a period of several months. With most prior art systems, the

enzyme must be added to the disinfecting composition each time the user cleans his lenses. A

further advantage of this feature is that the two compositions are admixed aseptically. This is

due to the fact that the bottle assembly containing the two compositions is assembled in an aseptic manner with an air-tight seal, thus sterile mixing is performed within the closed sterile

system of the bottle assembly. Still another advantage of this feature is that it eliminates

possible user error resulting from the addition of improper amounts of an enzyme composition

to the diluting solution. This is important as improper amounts of enzymes or excipients (e.g.,

salts) in the resultant multi-purpose solution can lead to ineffective cleaning and disinfecting of

the lens and/or ocular toxicity. Thus, user compliance with the cleaning regimen is perfected

with the present invention, allowing for the realization of maximum cleaning benefits, and the

avoidance of unnecessary ocular irritation/toxicity.

Another feature of the present invention is that the enzyme component is kept separate

from the diluting solution prior to initial use. This feature minimizes enzyme activity loss,

which naturally occurs over time in aqueous environments, by minimizing the time the enzyme

is solubilized prior to initial use. This feature allows for ambient temperature shipping, and

long shelf-life without significant loss of enzyme activity. When the user is ready to use the

system, the two components are combined and mixed aseptically, forming the multi-purpose

composition. The multi-purpose composition can then be used for a period of from about 1-3

months.

The cleaning and disinfecting compositions of the present invention may utilize

ingredients similar to known cleaning or disinfection formulations. Various modifications may

be made, however, to enhance the anti-microbial efficacy of the multi-purpose composition.

Other additional components may also be added to enhance the shelf-life of the mixed

components, such as the use of enzyme stabilizers.

The multi-purpose compositions and methods of the present invention provide greater

ease of use. This ease of use enables contact lens users to clean their lenses daily, thereby

achieving maximum proteolytic cleaning of their lenses. It has been found that daily use of the liquid enzyme compositions in multi-purpose compositions of the present invention results in

dramatically better cleaning, as compared to the once-a-week enzyme cleaning regimens

currently being used.

Detailed Description of the Invention

The present invention is directed to the use of a sterile two-part system for the

preparation of multi-purpose compositions useful for cleaning and disinfecting contact lenses.

The present invention is also directed to methods of cleaning and disinfecting contact lenses by

using a two-part system of the present invention. The first part ("Part I") is a sterile enzyme

containing solid (powder or tablet) or liquid composition and the second part ("Part II") is a

sterile diluting composition. An anti-microbial agent is further required, and may be included

in either composition.

The present invention requires the use of a two-compartment device to store and mix

the sterile two-part system, and to dispense the resultant sterile multi-purpose composition.

Various devices may be employed, but the central features of the device are that it provides

separate component storage, a means for aseptically adding one component to the other

component, a mixing chamber and a dispensing means, all in a single bottle assembly.

Figure 1 illustrates a preferred two-part bottle assembly for use with the two-part/multi-

purpose compositions of the present invention. The preferred two-part bottle assembly, bottle

assembly 1, generally comprises bottle 2 and container 4.

As illustrated in FIGS. 2-4, bottle 2 comprises neck 13, opening 10, external rings 12

and internal rings 43. Neck 13 is formed such that rings 12 annularly protrude from neck 13. Bottle 2 is made generally of molded polyethylene, although other materials such as

polyethyleneterphlalate (PET) and polypropylene (P/P) may be used.

As best seen in FIGS. 3 and 4, container 4 comprises housing 5, plunger 6, cap 8 and

collar 28. Housing 5 comprises hollow cylinder 14 and cap 16. Cylinder 14 has external

threads 36 annularly protruding near top end 15 and membrane disk 18 covering bottom end

17. Stops 23 are disposed annularly about exterior 38 of cylinder 14 (FIG. 7). Membrane 18

has thin cross-sectional thickness 49 about its circumference. Cap 16 has protruding internal

rings 20, and cylinder 14 is coaxially disposed within cap 16 such that top end 15 and bottom

end 17 project out of cap 16. Plunger 6 comprises hollow cylinder 24, open end 22, dispensing

end 25 and ribs 34. Open end 22 has tooth 39 and is thinner in cross-sectional thickness than

the thickness of hollow cylinder 24, thereby forming sharp point 41 of tooth 39. Cap 8

comprises pin 33, hollow cone 32, internal threads 30 and stops 21. As best seen in FIG. 8,

collar 28 has tab 29, spokes 19 and perforation 27 which forms ends 31. Container 4

components are generally made of molded high density polyethylene or polycarbonate, but

other materials and methods of manufacture such as P/P, PET, polystyrene and acrylonitrile

butadiene styrene (ABS) may be employed.

As illustrated in FIG. 4, container 4 is put together by first adding enzyme cleaning

composition 7 to hollow cylinder 14 of housing 5, ringing collar 28 over cylinder 14, inserting

plunger 6 within cylinder 14 such that rings 34 of plunger 6 compress against the interior of

cylinder 14, and screwing on cap 8 over plunger 6, engaging pin 33 of cap 8 with notch 26 of

plunger 6, by threading internal threads 30 within threads 36 of housing 5. In this

configuration, spokes 19 of collar 28 are interspersed between both stops 21 of cap 8 and stops

23 of housing 5. Cap 8 in this configuration (see FIGS. 2 and 5), is only partially threaded

within threads 36 of housing 5 due to the prevention of further downward rotation of cap 8 by collar 28. Aqueous composition 9 is added to bottle 2, container 4 is then placed over neck 13,

and cap 16 is forced down on neck 13 such that rings 20 compress radially against neck 13, and

exterior rings 12 compress against interior 47 of cap 16, forming an air-tight seal.

In operation, collar 28 is first removed from container 4 by screwing cap 8 downward

on housing 5. When cap 8 is rotated, stops 21 engage and pull spokes 19, while stops 23 hold

spokes 19 stationary. The resulting stress causes collar 28 to split at perforation 27. Split

collar 28 may then be removed by pulling on tab 29. Cap 8 is then further screwed down on

housing 5. With cap 8 rotation, plunger 6, is simultaneously pushed downward causing

plunger 6 to descend cylinder 14. When plunger 6 reaches membrane 18 of housing 5, sharp

point 41 punctures thin circumference 49 of membrane 18. Further rotation of cap 8 causes

open end 22 of plunger 6 to further descend, slicing off membrane 18 about its circumference

from housing 5, similar to the operation of a punch press. At this point the enzyme cleaning

composition contained in housing 5 is exposed to interior 1 1 of bottle 2 and falls into aqueous

diluting composition 9 of bottle 2. Bottle 2 may then be inverted and shook, thus affecting the

mixing of the enzyme and aqueous diluting compositions. When membrane 18 is cut away

from housing 5, a channel is formed which runs from bottle 2 through now open housing 5,

plunger 6 and dispensing end 25. With the removal of cap 8, the resultant multi-purpose

composition may now be dispensed through this channel to an appropriate container for

cleaning, disinfecting, rinsing and storing the contact lens.

Other embodiments of two-compartment bottle assemblies may be employed in the

present invention. For example, a blister pouch and piercing means may be utilized as the

enzyme compartment and break-away membrane component, respectively, of a bottle

assembly. As stated above, the present invention is comprised of two separate compositions which

are then combined before initial use. Part I comprises an enzyme and Part II comprises an

aqueous diluting solution. The resultant multi-purpose composition may contain various other

agents, but must contain: 1) an anti-microbial agent, 2) an enzyme, 3) a buffering agent, 4) a

tonicity agent, and 5) water. The multi-purpose compositions of the present invention are

intended to function as storing, rinsing, cleaning and disinfecting solutions. Therefore, the

multi-purpose compositions will be physiologically compatible with the eye.

The Part I sterile enzyme composition of the present invention is generally composed of

one or more enzymes and various carriers. The enzyme composition may be formulated as a

powder, tablet or liquid. Dry powder or tablet compositions may be preferred when the Part I

enzyme compositions need to be stable for longer periods of time than liquids. Excipients

which make up the enzyme powder compositions are known in the art. Generally, the enzyme

powder composition will include bulking agents to carry the relatively small volume of enzyme

into the diluting solution. Such bulking agents typically include polyols (e.g., mannitol or

soribitol), polyethylene glycols (molecular weights greater than 1000) and sugars. Other

excipients may include salts such as NaCl, chelating agents such as EDTA, and buffering

agents such as Tris. Other additives may include surfactants to ease dispersion and dissolution

of the powder in water. Preferred enzyme powder compositions comprise mannitol and

polyethylene glycol-5000 (PEG-5000).

Enzyme tablet compositions and methods of manufacturing are known in the art.

Enzyme tablets require the use of bulking agents and binding agents. Additionally, tablets may

contain effervescing agents such as bicarbonate to expedite dissolution of the tablet into the

diluting solution. Other excipients known in the art may be added to provide greater consistency and easier manufacture of the tablets. Preferred enzyme tablet compositions

comprise sodium bicarbonate, citric acid, PEG-8000, carboxymethyl cellulose and lactose.

Liquid enzyme compositions are preferred Part I compositions of the present invention

due to their ease of preparation, sterilization and dispensing within the enzyme container of a

bottle assembly. Liquid enzyme compositions and methods of manufacturing are known in the

art. Enzymes contained in Part I liquid compositions may be solubilized in aqueous

compositions or dispersed in non-aqueous compositions.

Aqueous enzyme compositions are generally preferred due to their ease of preparation

and sterilization. Aqueous enzyme compositions typically comprise one or more polyol(s) and

a borate or boric acid compound. Preferred aqueous enzyme compositions of the present

invention comprise a 2-3 carbon polyol and a borate or boric acid compound. As used herein,

the term "2-3 carbon polyol" refers to a compound with 2 to 3 carbon atoms and at least two

hydroxy groups. Examples of 2-3 carbon polyols are glycerol, 1,2-propane diol ("propylene

glycol"), 1,3-propane diol and ethylene glycol. Glycerol is the most preferred 2-3 carbon

polyol. The borate or boric acid compounds which may be utilized in the liquid enzyme

compositions of the present invention include alkali metal salts of borate, boric acid and borax.

Other excipients which may be included in the Part I aqueous enzyme compositions include

divalent ions such as calcium, enzyme stabilizing organic acids such as benzoic acid and

surfactants such as alkylethoxylates.

Non-aqueous enzyme compositions employed as Part I compositions of the present

invention generally comprise a crystalline enzyme uniformly dispersed in a water-soluble

organic liquid. Typical organic liquids include polyoxyethylenes (e.g., PEG-400) and alkoxy

polyoxyethylenes such as methoxy polyethylene glycols. In this composition, the enzyme is in

a dormant state, and following dissolution in a Part II composition of the present invention, the enzyme solubilizes and becomes active. Preferred non-aqueous enzyme compositions

comprise an enzyme in PEG-400.

As stated above, the anti-microbial agent(s) of the present invention may be included in

any of the enzyme compositions described herein. The actual amount of anti-microbial agent

will vary, but will provide effective disinfection of the contact lens, as described below.

The above-described Part I enzyme composition are aseptically processed generally by

sterile filtering the liquids, or lyophilization, aseptic processing and terminal gamma irradiation

of the solids. These and other methods of sterilizing liquids or solid compositions are well

known in the art.

The enzymes which may be utilized in the compositions and methods of the present

invention include all enzymes which: (1) are useful in removing deposits from contact lenses;

(2) cause, at most, only minor ocular irritation in the event a small amount of enzyme comes in

contact with eye; (3) are relatively chemically stable and effective in dilute saline solutions;

and (4) do not adversely affect the physical or chemical properties of the lens being treated.

The proteolytic enzymes used herein must have at least a partial capability to hydrolyze

peptide-amide bonds in order to reduce the proteinaceous material found in lens deposits to

smaller water-soluble subunits. Additionally, such enzymes may exhibit some lipolytic,

amylolytic or related activities associated with the proteolytic activity and may be neutral,

acidic or alkaline. Furthermore, separate lipases or carbohydrases may be used in combination

with the proteolytic enzymes. For purposes of the present specification, enzymes which satisfy

the foregoing requirements are referred to as being "ophthalmically acceptable."

Examples of ophthalmically acceptable proteolytic enzymes which may be utilized in

the present invention include, but are not limited to: pancreatin, trypsin, subtilisin, collagenase, keratinase, carboxypeptidase, bromelain, aminopeptidase, elastase, Aspergillo peptidase,

pronase E (from S griseus). dispase (from Bacillus polymyxa) and mixtures thereof.

Microbially derived enzymes, such as those derived from Bacillus. Streptomyces. and

Aspergillus microorganisms, represent a preferred type of enzyme which may be utilized in the

present invention. Of this sub-group of enzymes, the most preferred are the Bacillus derived

neutral or slightly alkaline proteases generically called "subtilisin" enzymes.

The identification, separation and purification of enzymes is known in the art. Many

identification and isolation techniques exist in the general scientific literature for the isolation

of enzymes, including those enzymes having proteolytic and mixed

proteolytic/lipolytic/amylolytic activity. The enzymes contemplated by this invention can be

readily obtained by known techniques from plant, animal or microbial sources.

With the advent of recombinant DNA techniques, it is anticipated that new sources and

types of stable proteolytic enzymes will become available. Such enzymes should be considered

to fall within the scope of this invention so long as they meet the criteria set forth herein.

Preferred genetically modified enzymes include BPN' subtilisin variants, such as those

described in PCT/US94/10020 (Procter and Gamble), WIPO Publication WO 95/30011

(Procter and Gamble) and U.S. Patent No. 4,990,452 (Genex Corp.). Specific preferred

subtilisins and variants include subtilisin Carlsberg, subtilisin PB92, subtilisin 309, subtilisin

147, subtilisin 168, subtilisin DY and truncations, modifications and variants thereof.

Other enzymes modified from their native structure may also be used in the present

invention. Such modifications include "pegylation," i.e., covalent bonding of polyoxyethylene

glycol derivatives to the enzymes, as well as monomeric covalent additions to the enzymes

with small organic compounds (e.g., methyl, ethyl, succinyl groups, and so on). These

modifications will generally prevent the enzymes from ionically binding to the contact lens, especially in the case of negatively charged hydrophilic soft lenses. Binding to the contact lens

can expose unnecessarily high amounts of the enzyme to the eye. With some enzymes, this

exposure can cause undesirable inflammatory responses. These modifications may also

improve the stability of enzymes in aqueous environments such as the Part I or multi-purpose

compositions of the present invention. It is believed that alkylation of hydro lyrically sensitive

cites of the enzyme limits the enzyme's autolysis.

Subtilisin and trypsin are preferred enzymes, and genetically modified subtilisin BPN's

are the most preferred enzyme for use in the present invention. Subtilisin is derived from

Bacillus bacteria and is commercially available from various commercial sources including

Novo Industries (Bagsvaerd, Denmark), Fluka Biochemika (Buchs, Switzerland) and

Boehringer Mannheim (Indianapolis, Indiana, U.S.A.). Trypsin is purified from various animal

sources and is commercially available from Sigma Chemical Co. and Boehringer Mannheim.

Subtilisin BPN' variants, as described above are genetically modified subtilisins which have

been described in 4,990,452 (Genex Corp.), PCT/US94/10020 (Procter and Gamble) and

WIPO Publication WO 95/30011 (Procter and Gamble). These enzymes may be obtained by

methods described in those publications.

Pancreatin is extracted from mammalian pancreas, and is commercially available from

various sources, including Scientific Protein Laboratories (Waunakee, Wisconsin, U.S.A.),

Novo Industries (Bagsvaerd, Denmark), Sigma Chemical Co. (St. Louis, Missouri, U.S.A.),

and Boehringer Mannheim (Indianapolis, Indiana, U.S.A.). Pancreatin USP is a mixture of

proteases, Upases and amylases, and is defined by the United States Pharmacopoeia ("USP").

The most preferred form of pancreatin is Pancreatin 9X. As utilized herein, the term

"Pancreatin 9X" means a filtered (0.2 microns) pancreatin containing nine times the USP

protease unit content. The Part I enzyme concentration will depend on various factors, such as: the enzyme or

combination of enzymes selected; the quantity of enzyme composition to be added to the Part

II aqueous composition; the purity, specificity and efficacy of the enzyme(s) selected; the

volume of the Part II aqueous composition; the type of lenses to be cleaned; and the intended

duration of each cleaning.

During storage, some of the activity of the enzyme may be lost, depending on length of

storage and temperature conditions. Thus, the Part I enzyme compositions of the present

invention may be prepared with initial amounts of enzyme that exceed the amount necessary to

achieve the final multi-purpose enzyme concentration ranges described herein. In general, the

Part I enzyme compositions of the present invention will preferably contain one or more

enzymes in an amount of from about 100-100,000 PAU/g or 100-100,000 PAU/mL.

The Part I enzyme compositions, however, will contain an effective amount of one or

more enzyme(s) sufficient to remove substantially or reduce significantly deposits of proteins,

lipids, mucopolysaccharides and other materials typically found on human-worn contact lenses

when a relatively small amount of a Part I enzyme composition is mixed with a Part II aqueous

diluting composition. As used herein, such a final enzyme concentration of the resultant multi¬

purpose composition of the present invention is referred to as "an amount effective to clean the

lens." However, the cleaning methods of the present invention will generally employ an

amount of the above-described enzyme compositions sufficient to provide a final enzyme

concentration in the multi-purpose composition of from about 1-100 PAU/mL of solution,

following dispersion of a Part I enzyme composition in a Part II composition. A final

concentration of about 5-25 PAU/mL is preferred. For purposes of this specification, a

"proteolytic activity unit" or "PAU" is defined as the amount of enzyme activity necessary to generate one microgram (meg) of tyrosine per minute ("meg Tyr/min"), as determined by the

casein-digestion, colorimetric assay described below.

Casein-digestion assay

A 5.0 mL portion of casein substrate (0.65% casein w/v) is equilibrated for 10 minutes

(min) ± 5 seconds (sec) at 37°C. An enzyme solution is prepared from a Part I enzyme

composition by solubilizing and diluting the Part I composition in PBS buffer. A 1.0 mL

portion of this enzyme solution (0.2 mg/ml) is then added to the casein substrate and the

mixture vortexed, then incubated for 10 min ± 5 sec at 37°C. After incubation, 5.0 mL of 14%

trichloroacetic acid is added and the resultant mixture immediately vortexed. The mixture is

incubated for at least another 30 min, then vortexed and centrifuged for 15-20 min (approx.

2000 rpm). The supernatant of the centrifuged sample is filtered into a serum filter sampler

and a 2.0 mL aliquot removed. To the 2.0 mL sample is added 5.0 mL of 5.3% Na₂CO₃. The

sample is vortexed, 1.0 mL of 0.67 N Folin's Phenol reagent is added, and the sample is

immediately vortexed again, then incubated for 60 min at 37°C. The sample is then read on a

visible light spectrophotometer at 660 nanometers (nm) versus purified water as the reference.

The sample concentration is then determined by comparison to a tyrosine standard curve. The

Part I concentration is then calculated by taking into account the dilution ratio.

The Part II aqueous compositions provide the volume of distilled water necessary for

the multi-purpose compositions of the present invention. In general, the Part II composition

may also contain sodium chloride and other excipients which together provide an

ophthalmically compatible solution. However, as noted above, Part I compositions may

contain a percentage or all of these ingredients, and Part II compositions may provide only a percentage of these ingredients, or none at all. As will be appreciated by those skilled in the

art, the Part II compositions utilized in the present invention may contain various other

components such as suitable buffering agents, chelating and/or sequestering agents and tonicity

adjusting agents. The Part II compositions may also contain surfactants. As stated above, the

anti-microbial agent may also be included in the Part II compositions. In general, the Part II

compositions will contain one or more anti-microbial agents (e.g., PHMB or polyquaternium-

1), a buffer (e.g., borate), citrates, tonicity agents (e.g., NaCl, sugars), a chelating agent (e.g.,

EDTA), and surfactants (e.g., block copolymers). Other agents which enhance the anti¬

microbial efficacy of the compositions, such as amino alcohols and alkylamines, may also be

added. Preferred Part II compositions comprise polyquaternium-1, sodium borate, boric acid,

propylene glycol and Pluronic P-103The most preferred Part II compositions comprise boric

acid, sorbitol, 95% 2-amino-2-methyl-l-propanol ("AMP-95"), sodium citrate, sodium

chloride, disodium edetate, polyquaternium-1, Tetronic 1304 and myristamidopropyl dimethyl

amine ("MAPDA").

s The multi-purpose compositions are intended to be used with various types of contact

lenses including rigid gas-permeable ("RGP") lenses and soft lenses. Depending on the type of

lens to be cleaned, the multi-purpose compositions may be optimized to effect maximum

cleaning benefits while minimizing ocular irritation/toxicity potential. For example, as soft

contact lenses are electronegatively charged, they tend to bind enzymes with high isoelectric

o points (i.e., more positively charged at the pH of a multi-purpose composition). This greater

exposure of enzyme to the eye, via an enzyme loaded lens, may lead to ocular

irritation/toxicity. Thus, the use of native or modified enzymes having lower isoelectric points

(e.g., subtilisin BPN' variants), and therefore less tendency for interaction with the soft lenses, is preferable. Less consideration of enzyme choice is necessary when RGP lenses are to be

treated, due to generally less enzyme binding potential of RGP lenses.

The cleaning obtained with the liquid enzyme compositions of the present invention is a

function of the time. The soaking times utilized will generally vary from about 1 hour to

overnight. However, if longer soaking periods (e.g., 24 hours) were to be employed, lower

concentrations than those described above may be utilized.

The cleaning methods of the present invention involve the use of a small amount of the

above-described enzyme compositions to facilitate the removal of proteins and other deposits

from contact lenses. The amount of enzyme composition used in particular embodiments of

the present invention may vary, depending on the enzyme concentration, as described above, as

well as various other factors, such as the purity of the enzyme, the proposed duration of

exposure of lenses to the compositions, the nature of the lens care regimen (e.g., the frequency

of lens disinfection and cleaning), the type of lens being treated, and the use of adjunctive

cleaning agents (e.g., surfactants). In general, about 1 gram of powder, 1 tablet or 1 milliliter

of a Part I compostion will be added to about 120 mL of a Part II composition, although greater

or lesser amounts are contemplated by the present invention.

The enzyme compositions of the present invention will demonstrate effective cleaning

efficacy while exhibiting minimal adverse effects or, more preferably, enhanced effects on the

anti-microbial activity of anti-microbial agents. The anti-microbial activity of disinfecting

agents, particularly polymeric quaternary ammonium compounds such as polyquaternium-1, is

adversely affected by high concentrations of sodium chloride or other ionic solutes. More

specifically, polymeric quaternary ammonium compounds, and particularly those of Formula

(I), below, lose anti-microbial activity when the concentration of ionic solutes in the multi¬

purpose compositions is too high. Generally, the multi-purpose compositions of the present invention will have tonicities/osmolalities in the range of hypotonic to isotonic, and more

preferably in the range of 150 to 350 milliOsmoles per kilogram (mOs/kg). A range of 200 to

300 mOs/kg is particularly preferred, and an osmolality of about 220 mOs/kg is most preferred.

The cleaning and disinfecting methods of the present invention utilize a multi-purpose

composition of the present invention containing an anti-microbial agent. Anti-microbial agents

will generally be non-oxidative polymeric anti-microbial agents which derive their anti¬

microbial activity through a chemical or physicochemical interaction with the organisms. As

used in the present specification, the term "polymeric anti-microbial agent" refers to any

nitrogen-containing polymer or co-polymer which has anti-microbial activity. Preferred

polymeric anti-microbial agents include: polyquaternium-1, which is a polymeric quaternary

ammonium compound; and polyhexamethylene biguanide ("PHMB") or polyaminopropyl

biguanide ("PAPB"), which are polymeric biguanides. These preferred anti-microbial agents

are disclosed in U.S. Patent Nos. 4,407,791 and 4,525,346, issued to Stark, and 4,758,595 and

4,836,986, issued to Ogunbiyi, respectively. The entire contents of the foregoing publications

are hereby incorporated in the present specification by reference. Other anti-microbial agents

suitable in the methods of the present invention include: other quaternary ammonium

compounds, such as benzalkonium halides, and other biguanides, such as chlorhexidine. The

anti-microbial agents used herein are preferably employed in the absence of mercury-

containing compounds such as thimerosal.

The most preferred anti-microbial agents are polymeric quaternary ammonium

compounds of the structure:

wherein:

R] and R₂ can be the same or different and are selected from:

N⁺(CH₂CH₂OH)₃X^",

N(CH₃)₂ or OH;

X^" is a pharmaceutically acceptable anion, preferably chloride; and n = integer from 1 to 50.

The most preferred compounds of this structure is polyquaternium-1, which is also known as

Onamer M (registered trademark of Onyx Chemical Corporation) or as Polyquad

(registered trademark of Alcon Laboratories, Inc.). Polyquaternium-1 is a mixture of the above

referenced compounds, wherein X^" is chloride and R_{1 ?} R₂ and n are as defined above.

The above-described anti-microbial agents are utilized in the methods of the present

invention in an amount effective to eliminate substantially or to reduce significantly the

number of viable microorganisms found on contact lenses, in accordance with the requirements

of governmental regulatory agencies, such as the United States Food and Drug Administration.

For purposes of the present specification, that amount is referred to as being "an amount

effective to disinfect" or "an anti-microbially effective amount." The amount of anti-microbial

agent employed will vary, depending on factors such as the type of lens care regimen in which

the method is being utilized. For example, the use of an efficacious daily cleaner in the lens

care regimen may substantially reduce the amount of material deposited on the lenses,

including microorganisms, and thereby lessen the amount of anti-microbial agent required to

disinfect the lenses. The type of lens being treated (e.g., "hard" versus "soft" lenses) may also

be a factor. In general, a concentration in the range of about 0.00001%) to about 0.01%> by

weight of one or more of the above-described anti-microbial agents will be employed. The most preferred concentration of the polymeric quaternary ammonium compounds of Formula

(I) is about 0.001% by weight.

The methods of the present invention will typically involve adding about 2-10 mL of a

multi-purpose composition of the present invention to a lens case, placing the soiled lens into

the dispensed multi-purpose composition, and soaking the lens for a period of time effective to

clean and disinfect the lens. Optionally, the contact lenses are first rubbed with a multi¬

purpose composition of the present invention or a surfactant cleaner prior to immersion in the

multi-purpose composition. The lens will typically be soaked overnight, but shorter or longer

durations are contemplated by the methods of the present invention. A soaking time of 4 to 8

hours is preferred. The methods of the present invention allow the above-described regimen to

be performed daily.

The following examples are presented to illustrate further, various aspects of the present

invention, but are not intended to limit the scope of the invention in any respect.

Example 1

A preferred Part I enzyme composition and a preferred Part II aqueous composition

containing an anti-microbial agent for use in a two-component bottle assembly/multi-purpose

composition of the present invention, are described below:

A. Part I Liquid Trypsin Composition

The following liquid enzyme composition represents a preferred enzyme composition

of the present invention :

Calcium chloride and boric acid are dispersed in 30% of the volume of purified water.

PEG and glycerol are then added. The pH of the solution is adjusted, and the enzyme is then

dissolved in the solution, followed by a final volume adjustment with purified water. The

composition is the sterile filtered using a 0.2 μm filter.

B. Part II Aqueous Composition

The following formulation represents a preferred aqueous composition:

The ingredients are dissolved with 90% of the volume of purified water, the pH is

adjusted, and the volume is then brought up to 100% volume. The composition is then sterile

filtered using a 0.2 μm membrane filter.

Various volumes of the above enzyme and aqueous compositions may be employed in a

two-compartment bottle assembly of the present invention. Preferred amounts include 1 mL of

the enzyme composition and 120 mL of the aqueous composition.

Example 2

The following is an example of a liquid enzyme composition of the present invention:

The above formulation is prepared by first sequentially mixing propylene glycol,

purified water, hydrochloric acid and sodium borate together. The required amount of trypsin

(about 0.3 w/v) is then dissolved the above mixture, the pH is adjusted and the solution is

brought to 100%) volume. The enzyme composition is then sterile filtered (0.2 μm filter). The

optimal pH of the above formulation will be in the range of 5-7; a pH of 6 is most preferred.

Example 3

The following are examples of preferred Part I solid enzyme compositions of the

present invention.

Part I Trypsin Tablet Composition

I. Part I Subtilisin Tablet Composition

The tablets are generally prepared by first mixing the appropriate amounts of each of

the ingredients and then passing the mixture through an oscillating granulator equipped with a

20 mesh hard screen. The screened ingredients are then added to a suitably sized blender and

mixed for 30 minutes. An appropriate amount of PEG and enzyme are then passed through a

20 mesh hard screen and this mixture is then added to the blender. The combined screened

ingredients are then blended for an additional 15 minutes. Using a tablet press equipped with a

5/32" tooling, the blended ingredients are then compressed into tablets having a target weight

of 50-80 mg and a hardness of 8 SCU. The tablets may then be sterilized by the method of

gamma-sterilization.

III. Part I Trypsin Powder Composition

The enzyme and lactose are dissolved in water (lg of enzyme/lactose per 1 mL of water) and sterile filtered using a 0.2 μm filter. The sterile enzyme solution as then aseptically lyophilized. Example 4

The following are examples of Part II aqueous compositions of the present invention:

Part II Aqueous Composition

Part II Aqueous Composition

These Part II compositions are prepared in a similar way as those of Example 1, above. The Part I and II compositions described in the Examples above will be combined, stored and mixed in a single bottle assembly in various quantities. In general, preferred amounts will be:

Part i: 1 g of powder or 1 tablet of a solid enzyme composition, or 1 ml of liquid enzyme composition. Part II: about 120 ml

(Similarly 2 g of powder, 2 tablets or 2 ml of liquid would be combined with about 240 ml of Part II.)

The preferred enzyme activity in the final multi-purpose solution will be about 5-25 PAU/ml.

Claims

What is Claimed is:

1. A two-compartment, sterile multi-purpose composition generating bottle assembly for use in cleaning, disinfecting, rinsing and storing a contact lens comprising: a) a bottle containing an aqueous composition; b) a sealed container comprising a break-away membrane and containing an enzyme composition containing an enzyme; and c) an anti-microbial agent in an amount effective to disinfect the lens; wherein the anti-microbial agent is included in either the aqueous composition or the enzyme composition, the container is secured to and partially within the bottle, forming an internally sterile, two-compartment bottle assembly and breaking away the membrane allows for sterile egress of the enzyme composition into the aqueous composition of the bottle, wherein a multi-purpose composition may be formed containing an amount of the enzyme effective to clean the lens and an amount of the anti-microbial agent effective to disinfect the lens.

2. A bottle assembly according to Claim 1, wherein: the container further comprises a housing, a plunger, a removable cap and a collar; the housing comprises a hollow cylinder containing the enzyme composition, a securing means, external threads and the membrane covers one end of the cylinder of the housing; the plunger comprises a hollow cylinder, a dispensing end, and a bevel opposite end; the cap comprises internal threads; and the bottle further comprises an open end, neck and a receiving means for receiving and securing the container; wherein the plunger is received within the hollow cylinder of the housing , the cap covers the plunger dispensing end and the internal threads of the cap are engaged with external threads of the housing, and the container is received and secured over the open end and within the neck of the bottle, forming an air-tight bottle assembly.

3. A bottle assembly according to Claim 1, wherein the enzyme is trypsin, subtilisin or a subtilisin BPN' variant.

4. A bottle assembly according to Claim 1, wherein the anti-microbial agent is polyquaternium- 1.

5. A bottle assembly according to Claim 1, wherein the aqueous composition comprises polyquaternium-1, boric acid, sorbitol, sodium chloride, sodium citrate, Tetronic 1304, disodium edetate, AMP-95, MAPDA, sodium hydroxide, hydrochloric acid and water; and the enzyme composition comprises boric acid, glycerol, PEG-400, calcium chloride, water and an enzyme selected from the group consisting of trypsin, subtilisin and a subtilisin BPN' variant.

6. A bottle assembly according to Claim 5, wherein the aqueous composition comprises: about 0.001%) w/v of polyquaternium-1 ; about 0.6%) w/v of boric acid; about 1.2% w/v of sorbitol; about 0.65%) w/v of sodium citrate; about 0.1% w/v of sodium chloride; about 0.05% w/v of Tetronic 1304; about 0.05%) w/v of disodium edetate; about 0.45% w/v of AMP-95; about 0.0005%) w/v of MAPDA; and water; wherein the composition is adjusted to pH

7-8 with sodium hydroxide and hydrochloric acid.

7. A method of preparing a sterile multi-purpose composition which comprises: employing a two-compartment bottle assembly, said bottle assembly comprising: a) a bottle containing an aqueous composition; b) a sealed container comprising a break-away membrane and containing an enzyme composition containing an enzyme; and c) an anti-microbial agent; wherein the anti-microbial agent is included in either the aqueous composition or the enzyme composition, and the container is secured to and partially within the bottle, forming an internally sterile, two-compartment bottle assembly; breaking away the membrane and allowing the enzyme composition of the container to egress into the aqueous composition; mixing the enzyme composition and aqueous composition together; and forming a multi-purpose composition containing an enzyme in an amount effective to clean the lens and an anti-microbial agent in an amount effective to disinfect the lens.

8. A method according to Claim 7, wherein: the container further comprises a housing, a plunger, a removable cap and a collar; the housing comprises a hollow cylinder containing the enzyme composition, a securing means, external threads wherein the membrane covers one end of the cylinder of the housing; the plunger comprises a hollow cylinder, a dispensing end, and a bevel opposite end; the cap comprises internal threads; and the bottle further comprises an open end, neck and a receiving means for receiving and securing the container; wherein the plunger is received within the hollow cylinder of the housing, the cap covers the plunger dispensing end and the internal threads of the cap are engaged with external threads of the housing, and the container is received and secured over the open end and within the neck of the bottle, forming an air-tight bottle assembly.

9. A method according to Claim 7, wherein the enzyme is trypsin, subtilisin, or a subtilisin BPN' variant.

10. A method according to Claim 7, wherein the anti-microbial agent is polyquaternium-1.

11. A method according to Claim 7, wherein the aqueous composition comprises polyquaternium-1, boric acid, sorbitol, sodium chloride, sodium citrate, Tetronic 1304, disodium edetate, AMP-95, MAPDA, sodium hydroxide, hydrochloric acid and water; and the enzyme composition comprises boric acid, glycerol, PEG-400, calcium chloride, water and an enzyme selected from the group consisting of trypsin, subtilisin and a subtilisin BPN' variant.

12. A method according to Claim 11 , wherein the aqueous composition comprises: about 0.001%) w/v of polyquaternium-1; about 0.6% w/v of boric acid; about 1.2%> w/v of sorbitol; about 0.65%) w/v of sodium citrate; about 0.1% w/v of sodium chloride; about 0.05%) w/v of Tetronic 1304; about 0.05%) w/v of disodium edetate; about 0.45% w/v of AMP-95; about 0.0005% w/v of MAPDA; and water; wherein the composition is adjusted to pH 7.8 with sodium hydroxide and hydrochloric acid.

13. A method of cleaning and disinfecting a contact lens which comprises: preparing a sterile multi-purpose composition by employing a two-compartment bottle assembly comprising: a) a bottle containing an aqueous composition; b) a sealed container comprising a break-away membrane and containing an enzyme composition containing an enzyme; and c) an anti-microbial agent; wherein the anti-microbial agent is included in either the aqueous composition or the enzyme composition, and the container is secured to and partially within the bottle, forming an internally sterile, two-compartment bottle assembly; breaking away the membrane and allowing the enzyme composition of the container to egress into the aqueous composition; mixing the enzyme composition and aqueous composition together; forming a multi-purpose composition containing an enzyme in an amount effective to clean the lens and an anti-microbial agent in an amount effective to disinfect the lens; dispensing the multi-purpose composition into a receptacle; and soaking the lens in the multi-purpose composition of the receptacle for a time sufficient to clean and disinfect the lens.

14. A method according to Claim 13, wherein: the container further comprises a housing, a plunger, a removable cap and a collar; the housing comprises a hollow cylinder containing the enzyme composition, a securing means, external threads wherein the membrane covers one end of the cylinder of the housing; the plunger comprises a hollow cylinder, a dispensing end, and a bevel opposite end; the cap comprises internal threads; and 5 the bottle further comprises an open end, neck and a receiving means for receiving and securing the container; wherein the plunger is received within the hollow cylinder of the housing, the cap covers the plunger dispensing end and the internal threads of the cap are engaged with external threads of the housing, and the container is received and secured over the open end and within l o the neck of the bottle.

15. A method according to Claim 13, wherein the enzyme is trypsin, subtilisin or a subtilisin BPN' variant.

15 16. A method according to Claim 13, where the anti-microbial agent is polyquaternium-1.

17. A method according to Claim 13, wherein the aqueous composition comprises polyquaternium-1, boric acid, sorbitol, sodium chloride, sodium citrate, Tetronic 1304, disodium edetate, AMP-95, MAPDA, sodium hydroxide, hydrochloric acid and water; and the

20 enzyme composition comprises boric acid, glycerol, PEG-400, calcium chloride, water and an enzyme selected from the group consisting of trypsin, subtilisin and a subtilisin BPN' variant.

18. A method according to Claim 17, wherein the aqueous composition comprises: about 0.001%) w/v of polyquaternium-1;

25 about 0.6%) w/v of boric acid; about 1.2% w/v of sorbitol; about 0.65% w/v of sodium citrate; about 0.1%) w/v of sodium chloride; about 0.05%) w/v of Tetronic 1304; 30 about 0.05%) w/v of disodium edetate; about 0.45% w/v of AMP-95; about 0.0005% w/v of MAPDA; and water; wherein the composition is adjusted to pH 7.8 with sodium hydroxide and hydrochloric acid.