Title: Cleaning, disinfecting and preserving contact lenses
5 FIELD OF THE INVENTION
The present invention relates to a method of cleaning, disin¬fecting and preserving contact lenses, a contact lens cleaning, disinfecting and preserving product, a tablet or capsule for 10 cleaning, disinfecting and preserving contact lenses and the use of an enzyme inhibitor for cleaning, disinfecting and preserving contact lenses.
15 BACKGROUND OF THE INVENTION
To enjoy the advantages gained by wearing contact lenses it is necessary to carry out the time consuming and cumbersome task of cleaninq and disinfection the contact flenses. The procedure 20 differs depending on the type of contact lenses in question e.g. hard lenses or soft lenses.
In all cases, the' contact lenses need to be cleaned and disinfected periodically,* to avoid infection and discomfort for 25 the wearer, in some cases every morning or evening.
When removed from the eyes the lenses must be stored in a preserving solution. Before wearing the lenses again they must be cleaned, disinfected and rinsed.
30
The cleaning operation is carried out to remove deposits and debri-s from the surface of the contact lenses. The cleaning effect is often, obtained ,by treatment with enzymes such as proteases, capable of. hydrolysing proteinaceous material to smaller water-soluble' subunits.

and making it impossible to wear contact lenses for a long period of time. Disinfecting agents such as hydrogen peroxide is widely used.
5 After the cleaning and/or disinfecting procedure the contact lenses need to be rinsed, to make sure that all enzymatic activities and/or disinfecting agent are removed, e.g. by using a physiological saline solution.
10 When the contact lenses are not worn the lenses need to be stored under sanitary conditions to secure that they are ready in a clean state for the next wear.
Further it is also important to make sure that the lenses are
15 treated with care to secure that e.g. the shape of the contact
lenses is maintained, staining of the lenses is prevented, an
acceptable oxygen permeability of the lenses is maintained etc.
Soil di^posits are foun'^ on P.T 1 groups of contac*" lenses, but -20 the easiness of removal differs among the groups. Hard contact lenses are easy to clean, due to only small amounts of soil deposited, and ease of removing soil by rubbing. Soft hydrophillic lenses are more prone' to adsorption of soil which is difficult to remove. One reason is that hard rubbing and 25 abrasives might damage the lens.
The major important soil deposits on contact lenses are proteins, lipid deposits and Jelly bumps, mucins, pigments and
inorganic compounds. |
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Wedler (J. Biomed. Mater. Res. Vol. 11, p. 525-535, 1977) has
identified tear proteins from ext]|:acts of contact lenses. Per
lens was found 5-10 ^g protein, 1.0-1.2 ixg carbohydrates, 5-25
^g phospholipids. Cholesterol and! glucose were not detected.
35 Albumin, lysbzyme, IgG and a^-lipoprotein were found in the
deposits. j

The main component of Jelly bumps deposits are lipids (Bilbaut et al., Exp. Eys. Res., Vol. 43, p. 153-165, 1986). These are often seen on contact lenses with high water content, particu¬larly extended wear contact lenses (Fohlzhofer, Deutsche Optiker Zeitung, Vol. 40, p.40-100, 1985 and Sack et al . Investigative Ophthalmology & Visual Science, Vol. 28, p; 842-849, 1987) .
A plethora of methods for removing deposits from contact lenses are known. Contact lenses are often cleaned with enzv-mes. US patent nr. 3,910,296 (Allergan) describes a method for cleaning contact lenses by the use of a protease.
US patent nr. 4,670,178 (Allergan) discloses a method for simultaneous cleaning and disinfection contact lenses with a protease in hydrogen peroxide. The cleaning is effected by protease and shown to be very efficient.
CA 1,146,881 (Bedding) points out a method for cleaning contact
lenses using enzymes, where the cleaning'procedure is followed
by rinsing of the lenses, e.g. with saline, to remove active
enzymes from the lens. ;
EP patent .nr. 257.942 (Hoya Corporation) describes a contact
lens cleaning kit comprising an oxidising agent and reducing
agent in such a form that they do not react with each other in
the kit. When placed in the water, at the same time, the miajor
portion of the oxidant dissolves m.ore rapidly than the major
portion of the reductant. The lefises can be worn immediately
i after treatment without the need 'for water washing.
CA patent application nr. " 2,044,072 (Webb), WO 93/17720 (Webb) and EP patent application nr. 196,151 (Hopkinson) disclose chloramine-T used for disinfectiiiig contact lenses. No use of proteases is mentioned in these patent documents.-
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i US patent nr. 5,057,414 (Stief et al.) concerns determining
activity of serine proteases and inhibitors in plasma, includ-

ing treatment with e.g. chloramine-T or chloramine-B as an oxidizing agent and a detergent to inactivate specific inhibitors. The patent does not concern cleaning or disinfect¬ing of contact lenses.
EP patent application nr. 147,100 (Ciba Geigy) concerns cleaning and disinfecting of contact lenses with a hydrogen peroxide solution in the presences of a solid sustained release composition which slowly releases a peroxide inactivat:or. The lenses may be treated with a wetting or ccmfcrt solution before inserting into the eyes. However, cleaning and disinfection with hydrogen peroxide does not remove proteinaceous deposits effectively from the surface of the contact lenses.
EP patent application nr. 279.401 (Dr. Thilo Sc Co. Gmbh) discloses a disinfection and cleaning product for contact
lenses containing a chlorine releasing compound, at least one protease and conventional formulatijon assistants. Initially the chlorine releasing compound, which must be characterized as a
strong disinfecting agent, is added to the solution. After
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sufficient disinfecting, the protease is added to clean .the
lenses by degrading protein deposits on the lenses surface. The
remaining chlorine releasing compound is inactivated by the
protease. After the disinfecting' and cleaning process the
contact lenses must be rinsed thoroughly to remove active
protease to avoid damage of the eyes.
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A drawback of the techniques disclosed in the prior art docu¬ments is that the cleaning and disiinfecting of contact lenses with enzymes must be succeeded by a thorough rinsing procedure to secure removal of all remainiing enzyme activity before inserting the contact lenses into the eyes. This makes the pro- ■ cedures cumbersome and implies a risk of forgetting the rinsing step, which may lead to exposing the eyes to enzymatic activity
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and/or disinfecting agents, which^will irritate or even might
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damage the eyes.1

SUMMERY OF THE INVENTION
It is the object of the invention to provide a facilitated and secure method for simultaneous cleaning, disinfecting and preserving contact lenses, which allows the contact lens wearer to insert the contact lenses after cleaning and disinfection, without additional rinsing or washing or followed by only sparingly rinsing.
The above mentioned problems are overcome by a method for simultaneous cleaning, disinfecting and preserving contact lenses comprising treating contact lenses in the following order with:
1) at least one enzyme,
2) at least one enzyme inhibitor,
3) at least one mild disinfecting agent, and
4) optionally rinsing in e.g. a physiological saline solution.
According to a preferred embodiment of the invention the enzyme inhibitor is a carbonyl hydrolase inhibitor, which is also a mild disinfecting agent.
In a specific embodiment of the invention the enzyme inhibitor is chloramine-T or chloramine-B.
A second object of the invention is to provide a contact lens cleaning, disinfecting and preserying product, comprising at least one enzyme, at least one er(zyme inhibitor and at least
one mild disinfecting agent. I
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Another object of the invention ; is to provide a tablet or capsule for cleaning, disinfecting and preserving contact lenses comprising at least one enzyme inhibitor.
In an embodiment of the tablet or capsule of the invention said
enzyme inhibitor is released slowly or delayed to the aqueous
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solution. ;

still another object of the invention is to provide for the use of an enzyme inhibitor for cleaning, disinfecting and preserv¬ing contact lenses.
In a specific embodiment of the invention chloramine-T or chloramine-B is used as said enzyme inhibitor.
DETAILED DESCRIPTION OF THE INVENTION
The present invention can be used with all groups of contact lenses including hard, soft, rigid gas permeable lenses and silicone lenses. Nevertheless, the invention is preferably employed with cleaning and disinfecting soft hydrogel lenses which absorb significant amounts of water.
Hydrogel lenses are commonly prepared from m.onomers or poly¬mers, such as N,N-dimethyl acylamide, 2-hydroxyethyl metha-
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crylate, hydroxyethylmethyl methactylate, N-vinyl pyrrolidone, poly vinyl pyrrolidone, vinyl acetate, glyceryl methacrylate, flour silicon methacrylate,- butyl methacrylate, isobutyl methacrylate, 3-methoxy-2-hydroxypropyl methacrylate, pentyl methacrylate, cyclohexyl methacrylate, alkyl methacrylate, glycerol methacrylate, methyl methacrylic acid, methacrylic acid or methacrylic acid ester, and the like.
The object of the invention is tO provide a facilitated and secure method for simultaneously , cleaning, disinfecting and preserving contact lenses comprisir.g treating contact lenses in the following order with: '
1) at least one enzyme, "i
2) .at least one enzyme inhibitor,
3) at least one disinfecting agenti, and
4) optionally rinsing in e.g. phys'iological saline solution.
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! According to the present inventjion the enzyme used as a
cleaning agent is added before t!he mild disinfection agent
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and/or the enzyme inhibitor. This will secure that the eyes will not be damaged even if the rinsing procedure is not used or forgotten.
The optional rinsing step is performed to make sure that the remaining disinfecting agent is removed from the lenses. It is to be understood that the step may be superflous and may be left out, due to the use of a mild disinfecting agent which is acceptable for the eyes.
In this case it is possible to use only one solution to clean, disinfect and store contact lenses, which makes the method less cumbersome in comparison to prior art methods.
If the enzyme inhibitory effect is reversible the optional rinsing step is mandatory. This is due to the risk that the inhibitory effect of the enzyme inhibitor ceases to exist, e.g. when diluted in an aqueous solution or tear solution, change of the physical conditions, such as ;pH and ionic strength, the precen^^c i^f oi-her coruponents etc.
However, it is to be understood that this does not imply that
it is mandatory that the enzyme' inhibitor is an irreversible
enzyme inhibitor, but it is required that the enzyme inhibitor
inhibit enzyme activity to such an ;extend that the eyes are not
damaged during wear of the contact! lenses.
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In an embodiment of the invention daid contact lenses are first
immersed in an aqueous solution, sejcondly 'treated with at least
enzyme, for a period of time sufficient to degrade deposits on
the contact lenses' surface, ther^ treated with at least one
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enzyme inhibitor for a period of j time sufficient to inhibit remaining enzyme, and finally disinfected.
The enzymes used for the cleaning iof contact lenses according to the invention are carbonyl jhydrolases, which exhibits proteolytic, lipolytic, amylolytiq or related activities.

• The enzymes may be neutral, acidic or alkaline. However, it is preferred that the enzymes have substantial activity at pH between 6.0 and 8.5.
Preferred enzymes used for the cleaning process are proteases selected from the group comprising serine proteases, acidic aspartic proteases, cysteine proteases and metallo proteases, respectively. As suitable enzymes are also contemplated trun¬cated, modified enzymes or variants of the above listed groups.
Examples of preferred serine proteases are e.g. trypsins, chymotrypsins and subtilisins.
Most preferred are the Bacillus derived alkaline serine proteases, such as subtilisin BPN', subtilisin Carlsberg, subtilisin PB92, subtilisin 309, subtilisin 147, subtilisin
168, subtilisin DY, aqualysin .or thermitase, truncations,
modification and variants thereof.
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Cpeclfic examples of cysteine proteases axe e.g. papain and bromelain.
To the group of suitable metalloiproteases are e.g. Neutrase® and collagenase.
Specific examples of acidic aspartic proteases are e.g. pepsin A, pepsin B, pepsin C, chymosin, cathepsin B and renin.
In an embodiment of the invention the enzyme inhibitor is a
i carbonyl hydrolase inhibitor. Al$o contemplated are reversible
i enzyme inhibitors acting as irreversible, enzyme inhibitors
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under the conditions present in t|:he eyes.
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Examples of metallo protease inhibitors are EDTA and metal
chelating agents. ,, !
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I Specific examples of enzymes that; inhibit serine proteases are
chloramine-T and chloramine-B.

In a preferred embodiment of the invention said enzyme inhibi¬tor exhibits a mild disinfecting effect on the contact lenses.
Chloramine-T and chloramine-B are specific examples of com¬pounds exhibiting enzyme inhibitory effect as well as disin¬fecting effect.
Other examples of combined enzyrrie inhibitors/disinfectants are bacitracin and aryl boronic acids.
According to the invention the enzyme is present in a concen¬tration sufficient for degrading deposits on the surface of the contact lenses and the enzyme inhibitor is present in a concen¬tration sufficient to inhibit all remaining enzyme activity.
The specific amounts of enzyme and enzyme inhibitor are easily determined by one skilled in the art and are dependent upon the time allowed for removing the depiosits, the activity of^ the enzyme and enzymie inhibitor, the purity of the enzyme etc.
In a specific embodiment of the invention chloramine-T is used as the enzyme inhibitor and the disinfecting agent. Chloramine-T is present in a concentration of 10.0001% to 5%, preferably of 0.001% to 1%.
Another object of the invention is to provide a contact lens cleaning, disinfecting and preserving product, com.prising at least an enzyme and at least an enzyme inhibitor.
In an embodiment of the inventioji the product comprises an aqueous solution and a tablet. Sajid solution preferably com¬prises an enzyme and said tablet coimprises an enzyme inhibitor.
In another embodiment of the invention the contact lens product comprises at least two tablets, ine of which comprises said--eriT-u-mp and fhe other comorises saijd enzyme inhibitor.

Preferably the product comprises a multi layer tablet, wherein an outer layer or coating comprises said enzyme(s! and an inner layer or core comprises said disinfecting agent and enzyme in¬hibitor. Said core and outer layer may be separated by a barrier or a membrane.
Said barrier may in an embodiment of the invention be made of a water soluble polymer layer, preferably a water soluble film.
Examples of said water soluble film comprises polymers soluble in an acidic medium, such as polymers of dimethylaminomethacry-late and neutral methacrylate esters.
Alternatively the film comprises a pK neutral soluble pol;ym:ier. Suitable polymers are e.g. soluble cellulose ethers, such as methylcellulose,methylhydroxycellulose , methylhydroxyethylcel -lulose, hydroxypropylcellulose, hydroxyethylcellulose, sodium carboxymethylcellulose, cellulosej acetate phthalate, hydroxy-propylmefhy"! ce."! lulose phthalate, d pclyaier of methacrylic acid and methacrylate esters, a copolymer of methacrylic acid and methacrylate esters, a copolymer; of methyl vinyl ether and
maleic acid anhydride and polyvinyl alcohols.
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In still another embodiment the contact lens product comprises
a tablet comprising a sparingly sbluble matrix comprising the
enzyme (s) wherein the enzyme inhibitor is dispersed or distri¬
buted, i
)
In a preferred embodiment the talfclet is a controlled release
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tablet. I
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Suitable plasticizers of polyhydrjic alcohols and water may be
added to the above listed soluble film polymers to control the
diffusion rate. Preferred plasticizers for this purpose are
I 1, 2-propylen<3 glycol, polyethylene glycols and citrate esters.
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In a specific example the enzyme inhibitor is chloramine-T or chloramine-B, preferably present in a concentration of 0.0001% to 5%, preferably 0.001% to 1%.
Considered as suitable enzyme inhibitors are also peptide alde¬hydes, peptide ketones, such as peptide chlororaethyl ketones, and cyclic peptides, such as bacitracin, and aryl boronic acids.
Suitable enzymes which may be used according to the invention are mentioned above.
Still another object of the invention is to provide a tablet or capsule for cleaning, disinfecting and preserving contact lenses, comprising an enzyme inhibitor, which may further comprise an enzyme.
In a specific embodiment of the inyention the tablet or capsule comprises chloramine-T or chloi^amine-E as the er'^yme inhibitor.
In a preferred embodiment the tablet or capsule is of the con¬trolled release type, wherein said enzyme is first released and said enzyme inhibitor is released^ after a time sufficient for the said enzyme to degrade composites on the contact lenses.
In an alternative embodiment said enzyme inhibitor is released
slowly or delayed to the aqueous Solution.
A final object of the invention isj to provide for the use of an enzyme inhibitor in the cleaning,' disinfecting and preserving of contact lenses. The enzyme inhibitor may be' selected from the group of compounds mentioned above, such as a carbonyl hydrolases.
^In a specific embodiment the enzyme inhibitor i-s chloramine-T or chloramine-B.

According to the invention the disinfecting agent used must be a mild disinfecting agent.
Additional components may be added to or incorporated into the tablets or capsules which do not substantially decrease the activity of the active components.
Examples are components such as effervescing agents, stabi¬lizers, buffers, chelating agent and/or sequestering agents, colouring agent, tonicity adjusting agents, surfactant and the like. In addition binders, lubricants, carriers, and other excipients normally used in producing tablets may be incorpor¬ated.
Examples of suitable buffering agent include alkali metal salts, such as potassium or sodium carbonates, acetates, bora¬tes phosphates, citrates, and hydroxides, and weak acids such as acetic and boric acids. Effervescing agents are typically lemployed when the enzyme is provided i solid form. Examples of suitable effervescing agent include, tartaric or citric acid used in combination with suitable alkali metal salts, such as sodium carbonate.
In the case of the cleaning, disinfecting and preserving product comprising an aqueous solution, it may contain one or miore of suitable buffering agents :(as listed above) , chelating agents and/or sequestering agent, tonicity adjusting 'agent and
surfactant. |
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Suitable tonicity adjusting agentsjinclude sodium and potassium
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chloride, dextrose, calcium and maignesium chloride.
Suitable surfactants can either bei cationic, anionic, nonionic or amphoteric. Preferred surfactant.s are neutral or nonionic.
i Specific examples include polyethylene glycol ethers of fatty
acids, polyoxypropylene ethers of ,C12-C18 alkanes and polyxye-

thylene, polyoxypropylene block copolymers of ethylene diamine (i.e. poloxamine) .
Examples of preferred chelating agents include Ethylenediami-netetraacetic acid (EDTA) and its salts (disodium) and certain polyvinyl alcohols.
MATERIALS AND METHODS
Enzymes:
Savinase® : Alcalophilic subtilisin from Bacillus lentus
Subtilisin A®: Subtilisin Carlsberg type
Esperase® : Alcalophilic subtilisin from Bacillus lencus
All enzymes are available from Novo Nordisk A/S.
Chloramine-T:
Chloramine T (Trihydrate) p,a. Merck art 2126
Mw = 281.69 g/mol, 1% equals approx. 36 mM
Protease activity analysis with SUc-Ala-Ala-Pro-Phe-pNA: The substrate (succinyl-Alanine-Al^nine-Proline-Phenylalanine-para-nitroanilide. Sigma no. S-7388, Mw 624.6 g/mole.
Proteases especially chymotrypsin Icleaves the bond between the
peptide and p-nitroaniline to give a visible yellow colour
absorbing at 4 05 nm. i
Buffer: e.g. Britton and Robinsonibuffer pH 8.3
i Substrate: 100 mg suc-AAPF-pNA is jdissolved into 1 ml dimethyl
sulfoxide (DMSO) . 100 /il of this is diluted into 10 ml with
Britton and Robinson buffer. 1
t Analysis: Substrate and protease! solution is mixed and the
i absorbance is monitored at 405 nm as a function of time and
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ARC; .. /m-i n Th^ ^Rmnpr,Ttnrp shoiild he^ controlled (20-50°C

depending on protease) . This is a measure of the protease activity in the sample.
Contact lenses:
Revolution, SunSoft, type 4
Buffer:
0.05 M K-phosphate
Britton and Robinson buffer pH 8.3
Solutions:
Solution A: 1 mg/ml solution of suc-Alanine-Alanine-Proline-
Phenylalanine-para-nitroanilide (s-AAPF-pNA)
Substrate: 100 mg suc-AAPF-pNA is dissolved into 1 ml dimethyl
sulfoxide (DMSO) . 100 i^l of this is diluted into 10 ml with
Britton and Robinson buffer.
Procedures: i
Te_st for the inhibitory effect of chlo^,qmine-T The enzyme is incubated for 5 minutes, 1 hour, 4 hours and 27 hours in MilliQ-water and 0.9% NaCl aqueous solution as incuba¬tion solutions with and without chloramine-T. Then protease ac¬tivity analysis are performed, using the suc-AAPF-pNA method, and using a non-incubated enzyme solution as a blind.
The incubation solutions are diluted to 3*10"' and 3*10'^
KNPU(S)/ml. ,
Test for protease activity on coijitact lenses
A contact lens (sunsoft) is soaked in 1.5 ml of the protease
solution for 20 hours at room teihperature.
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The lens is rinsed in buffer and divided into two.
One half lens is then soaked forj 1 hour in 1% chloramine-T in
buffi^r, the other half lens is soaked'in buffer.

Thereafter the residual protease activity on the lens is mea¬sured by applying 7.5 /il of solution A and incubated in a sealed container for 20 minutes.
Protease activity will cause solution A to hydrolyse and pro¬duce a yellow colour on the surface of the lenses.
EXAMPLES
Experiments
The following experiments were preformed as described in the
section "METHODS AND MATERIALS".
All enzymes and solutions used are described in the section "METHODS AND MATERIALS".
Example 1
Experiment A:
The inhibitory effect of chloramine-T was tested on Savinase*^ in MilliQ-water (table 1) and 0.9% NaCl aqueous solution (table 2) :
In table 1 and table 2 the results of the analysis are dis¬played.


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Ex-periment B : |
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The inhibitory effect of chlorami'ne-T was tested on subtilisin
A in MilliQ-water (table 3) and iiji a 0.9% NaCl aqueous solution
(table 4): I
In table 3 and table 4 the results of the analysis are dis-played.


Experiment C: [
I
The inhibitory effect of chloramine-T was tested on Esp<
in MilliQ-water (table 5) and in a 0.9% Nail aqueous so.'
(table 6) : I
25 '
In table 5 and table 6 the results of the analysis are
played. '


CiXo-ITlkJ-Lc: ^ I
'^ (
Test of the protease activity on jcontact lenses
Solutions of 0,01 KNPU Savinase/rjil, 0.01 M KNPU Esperase®/ml,
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and 0,002 subtilisin A AU/ml, respectively, all in K-phosphate buffer, were tested for protease activity, as described above under "Methods and Materials". !
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All lenses soaked in buffer shbwed the presence of active
protease on the lens after rinsing.
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All lenses soaked with chloramine-T showed no protease activ¬ity. This result indicated that even adsorbed protease can be inhibited by adding an enzyme inhibitor.
5 As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without depart¬ing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the 10 substance defined by the following claims.

1. A method of cleaning, disinfecting and preserving contact
lenses comprising treating contact lenses in the following
order with:
1) at least one enzyme,
2) at least one enzyme inhibitor,
3) at least one disinfecting agent, and
4) optionally rinsing in e.g. physiological saline solution.
2. The method according to claim 1, wherein the said contact
lens is:
1) immersed in an aqueous solution,
2) treated with an enzyme, for a period of time sufficient to degrade deposits on the contact lenses' surface,
3) treated with an enzyme inhibitor for a period of time
sufficient to inhibit remaining ehzyme, and
4) disinfected.
3. The method according to the 'claims 1 to 2, wherein the
enzyme is a carbonyl hydrolase, preferably a protease, such as
an acidic aspartic protease, a cysteine protease, serine
protease or a metallo protease.
4. The method according to the claim 3, wherein the enzyme is
an acidic aspartic protease, such as pepsin A, B or C, or
cathepsin D.
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5. The method according to the claim 3, wherein the enzyme is
a cysteine protease, such as papain.
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6. The method according to the claim 3, wherein the enzyme is
i a metallo protease, such as Neut^ase®.

7. The method according to the claim 3, wherein the enzyme is
a serine protease, preferably of the subtilisin type, including
alkalophilic subtilisins.
8. The method according to the claims 1 to 7, wherein the
enzyme inhibitor is a carbonyl hydrolase inhibitor.
9. The method according to any of the claims 1 to 8, wherein the enzyme is present in a concentration sufficient for degrading deposits on the surface of the contact lenses and the enzyme inhibitor is present in a concenuration sufficient to inhibit all remaining enzyme.
10. The method according to any of the claims 1 to 9, wherein said disinfecting agent is also an enzyme inhibitor.
11. The method according to any of the claims 1 to 10, wherein the enzyme" inhibitor is chloramine-T or chloramine-B.
12. The riicithod according Lu any of the claims 1 to lu, wnerem the enzyme inhibitor is selected from the group of peptide aldehydes, peptide ketones, such as peptide chloromethyl ketones, cyclic peptides, such aS; bacitracin and aryl boronic acids.
13. The method according to claim 11, wherein chloramine-T or chloramine-B is present in a concentration of 0.0001% to 5%, preferably 0.001% to 1%. '
14. A contact lens cleaning, jiisinf ecting and preserving
, product, comprising at least one Qnzyme and at least one enzyme
inhibitor.
15. The contact lens product, accqrding to claim 14, comprising
i an aqueous solution and a tablet.!

16. The contact lens product, according to claim 15, wherein said solution comprises an enzyme and said tablet comprises an enzyme inhibitor.
17. The contact lens product, according to claim 14, comprising at least two tablets, one of which comprises said enzyme and the other comprises said enzyme inhibitor.
18. The contact lens product, according to claim 14, comprising a multi layer tablet, wherein an outer layer or coating com¬prises said enzyme(s) and an inner layer or core comprising said disinfecting agent and enzyme inhibitor.
19. The contact lens product, according to claim 18, wherein said core and outer layer are separated by a barrier or a membrane.
20. The contact lens product, according to claim 19, wherein said barrier is a water soluble |polymer layer, preferably a water soluble film.
21. The contact lens product, according co claim 20, wherein said soluble polymer layer', comprises compounds selected from the group of polymers of dimethylaminomethacrylate, soluble cellulose ethers, such as methylcellulose, methylhydroxycellu-lose, methylhydroxyethylcelluloSe, hydroxypropylcellulose, hydroxyethylcellulose, sodium carbox-yir.ethyl cellulose, cellu¬lose acetate phthalate, hydroxypropylmethylcellulose phthalate, a polymer of methacrylic acid and methacrylate esters, a copolymer of methacrylic acid and methacrylate esters, a copolymer of methyl vinyl ether arid maleic acid anhydride, and
polyvinyl alcohols. |
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22. The contact lens product, according to the claims 18 or 19,
wherein said tablet also compri&es a plasticizer, such as
polyhydric alcohols, preferab|le X, 2-propylene glycol,
polyethylene glycols and citrate festers.

23. The contact lens product, according to claim 14, comprising
a tablet comprising a sparingly soluble matrix comprising the
enzyme(s), wherein the enzyme inhibitor is dispersed or
distributed.
24. The contact lens product, according to claim 14, compris¬
ing a controlled release tablet.
25. The contact lens product, according to any of the claims 14
to 24, wherein the enzyme inhibitor is chloramine-T or
chloramine-B.
26. The contact lens product according to claim 25, wherein
chloramine-T or chloramine-B is present in a concentration of
0.0001% to 5%, preferably 0.001% to 1%.
27. The contact lens product, according to any of the claims 14
to 24, wherein the enzyme inhibitor is selected from the group
of peptide aldehyd'^s peptide ketones, such as peptide chlcro-
methyl ketones, cyclic peptides, such as bacitracin, and aryl
boronic acids.
28. The contact lens product, according to claim 14 to 24,
j wherein the enzyme is a carbonyl hydrolase, preferably a
protease such as a serine protease, especially of the subtili-
sin type including alkalophilic subtilisins.
i 29 . A tablet or capsule for cleaning, disinfecting and preserv¬ing contact lenses, comprising 3|n enzyme inhibitor.
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30. The tablet or capsule acpording to claim 29 further
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comprising an enzyme. I
31. The tablet or capsule according to claim 29 to 30, wherein
the enzyme is a carbonyl hydrolase, preferably a protease, such
as an acidic aspartic proteasei a cysteine protease, serine
protease or a metallo protease, i
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32. The tablet or capsule according to claim 30 to 31, wherein the enzyme is an acidic aspartic protease, such as pepsin A, B or C, or cathepsin B.
33. The tablet or capsule according to claim 30 to 31, wherein the enzyme is a cysteine protease, such as papain.
34. The tablet or capsule according to claim 30 to 31, wherein the enzyme is a raetallo protease, such as Neutrase®.
35. The tablet or capsule according to claim 30 to 31, wherein the enzyme is a serine protease, preferably of the subtilisin type, including alkalophilic subtilisins.
36. The tablet or capsule according to claim 35, wherein the said serine protease is a subtilisin, such as subtilisin BPN', subtilisin Carlsberg, subtilisin PB92, subtilisin 309, subtili¬sin 147, subtilisin 168, subtilisin DY, aqualysin or thermitase, truncations, modifications ^nd variants th^r^of^
37. The tablet or capsule according to claim 29, wherein the" enzyme inhibitor is chloramine-T or chloramine-B.
38. The tablet or capsule of any of the claims 29 to 37, which is of the controlled release type,; wherein said enzyme is first released and said enzyme inhibitor is released after a time sufficient for said enzymie to degrjade composites on the contact
lenses.
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39. The tablet or capsule of ai^y of the claims 29 to 38,
wherein said enzyme inhibitor is [released slowly.
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40. A tablet or capsule of any of the claims 29 to 39, wherein said enzyme inhibitor is released delayed.
41. Use of an enzyme inhibitor ip. the cleaning, disinfecting and preserving of contact lenses.;

42. The use of an enzyme inhibitor according to claim 41,
wherein the enzyme inhibitor is a carbonyl hydrolase inhibitor.
43. The use of a enzyme inhibitor according to claim 41 to 42,
5 wherein the enzvTne inhibitor is chloramine-T or chloramine-B.
44. The use of a enzyme inhibitor according to claim 41 to 43,
wherein the enzyme inhibitor is selected from the group of
peptide aldehydes, peptide ketones, such as peptide chlorome-
10 thyl, cyclic peptides, such as bacitracin, and aryl boronic acids.
45 A method of cleaning, disinfecting and preserving contact lenses, substantially as herein described, and exempli fled.
46. A contact lens cleaning, disinfecting and
preserving product, substantially as lierem descrioed, and exemp1i fled.