Water-soluble contact lens care product

A water-soluble, solid contact lens care agent (1) having at least a first (2) and a second (3) compartment containing within the first compartment (2) at least one agent, in particular a protease, for removing or supporting the cleaning of metabolic deposits on a contact lens and within the second compartment (3) at least one agent being capable of neutralizing a contact lens disinfecting solution, characterized in that the first compartment (2) is dissolved faster within the contact lens disinfecting solution than the second compartment (3) and both compartments (2, 3) are simultaneously subjectable to the contact lens disinfecting solution.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 Subject matter of the present invention is a water-soluble, solid contact
 lens care agent.
 2. The Prior Art
 Contact lenses are much in demand with individuals suffering from
 ametropia. Still, one problem with the use of contact lenses is the
 correct care thereof. There is known a multitude of different systems
 having essentially in common that a disinfection of the contact lens is
 effected after wearing the contact lens, usually during the night, where
 disinfection is effected by chemicals which have to be neutralized
 subsequently due to the aggressive character thereof. For this purpose a
 multiplicity of care agents has been successful on the market, e.g., an
 aqueous hydrogen peroxide solution as disinfecting solution which is
 neutralized or decomposed by subsequent steps. To this end, several
 systems such as the catalytic decomposition on precious metal surfaces,
 the enzymatic decomposition using, e.g., catalase, and the chemical
 neutralization by reduction of the hydrogen peroxide by sodium thiosulfate
 are known in the art. The problem of removing metabolic deposits, in
 particular protein deposits on the lenses or within the lens material, has
 in principle been solved in the art as well. For this, e.g., agents
 containing protease are added during a preliminary cleaning step. In
 particular, subtilisin has to be mentioned as a protease removing any
 protein deposits within the matrices of soft contact lenses. The state of
 the art is represented by EP 0 219 220. There, a combined contact lens
 care agent is described which both disinfects and cleans the contact
 lenses. In this case, a solution of hydrogen peroxide and a protease being
 active in a peroxide-containing solution effects disinfection. As a
 suitable protease subtilisin is mentioned.
 Removing any metabolic deposits, in particular protein deposits, within the
 contact lens matrices is extremely important as these deposits result in
 changes of the lens matrix including changes of the optical properties and
 the generation of inflammations.
 Although various systems have been available in the market, caring
 especially for soft contact lenses seems to be so complicated that
 recently so-called one-way contact lenses have been marketed increasingly.
 Here, cleaning and disinfecting is no longer in the fore as the contact
 lenses are simply disposed after a certain wearing time. On the other
 hand, this results in the fact that only ready-made, mass-produced
 articles can be offered as any individual adaption of the contact lens is
 too costly, so that an individually adapted one-way lens will be
 unattainable. However, when dispensing with individual adaptions patients
 are provided with contact lenses lacking optimal properties, so that such
 a way of proceeding is not advisable from the physiological point of view.
 The state of the art is especially detrimental in that proteases are
 usually employed in a separate cleaning step which is arranged prior to
 the disinfection. Because of this a high willingness of the user to
 perform the cleaning and disinfection correctly is demanded. After
 performing the cleaning using proteases, this protease solution usually is
 discarded and subsequently a separate disinfection phase is performed.
 This two-stage process is often considered to be cumbersome by users and
 promotes an improper mode of behavior due to a negligent use. Thus, for
 example, it may happen that the disinfecting step is forgotten and the
 lens is put on directly from the protease solution. In a different method
 a protease is added to the disinfecting solution, said protease, however,
 being added in such a high amount that the protease has to be eliminated
 by a physiological solution after the cleaning step. Otherwise, too much
 protease would remain within the contact lens matrix possibly resulting in
 irritations on the user's eye.
 SUMMARY OF THE INVENTION
 Consequently, it is the object of the present invention to provide systems
 which allow contact lenses to be cleaned and disinfected in a simple way.
 Surprisingly, the object of the present invention is achieved in a simple
 way by a contact lens care agent having the features of the invention.
 The contact lens care agent according to the invention has at least a first
 and a second compartment. The first compartment contains at least one
 agent, in particular metabolic protease, for removing or supporting the
 cleaning of protein-like deposits on a contact lens. The at least second
 compartment contains at least one agent being capable of neutralizing a
 contact lens disinfecting solution. Here, it is essential for the
 invention that the first compartment will dissolve quicker in a contact
 lens disinfecting solution than the second compartment. Both compartments
 can be subjected to the contact lens disinfecting solution at the same
 time. Proteases, in particular proteases of the serine type, are suited
 for the metabolic deposits removing agent. An enzyme class known as
 alkaline proteases, generally as subtilisin, is particularly preferred.
 Suitable enzymes have been characterized in EP 0 219 220.
 The second compartment contains a contact lens disinfectant, wherein in the
 case of an aqueous hydrogen peroxide solution enzymes such as catalase or
 chemicals such as sodium dithionite are to be mentioned.
 Preferably, the contact lens care agent according to the invention consists
 of a fist compartment and a second compartment. In one embodiment the
 first compartment encloses the second one completely. Preferably, however,
 the first compartment is enclosed by the second compartment not completely
 or only partially on all sides. Thereby, a simultaneous access of the
 disinfecting solution to the compartments is enabled. In a particular
 embodiment the first embodiment encloses the second compartment at least
 concentrically. In another embodiment of the contact lens care agent
 according to the invention said agent forms a formed piece having two axes
 being perpendicular to each other, wherein the first compartment is
 located around a first axis and the second compartment is located around a
 second axis. Preferably, the compartments are arranged rotationally
 symmetrical around one axis.
 The disinfectant contacts the compartments and dissolves the first
 compartment quicker than the second compartment. The dissolution of the
 first compartment can be accelerated by additives. As additives in
 particular substances forming a readily soluble matrix or mixtures of
 substances generating effervescence in aqueous solution may be used.
 Especially preferred is the use of additives contributing to the formation
 of an isotonic solution subsequent to the dissolution of the compartments.
 The second compartment may contain additives retarding a dissolution of the
 second compartment. This can be realized, e.g., by using substances or
 mixtures of substances which are more sparingly soluble than those being
 used in the first compartment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
 FIG. 1 illustrates a preferred embodiment of the contact lens care agent
 according to the invention. Here, a formed piece configured essentially
 cylindrically is the second compartment 3 containing subtilisin as
 protease. Said essentially cylindrical formed piece 3 containing
 subtilisin compressed within a usual tablet matrix is partially
 encompassed by the first compartment 2 having a toroidal shape, in the
 center of which the essentially cylindrical formed piece 3 of the first
 compartment is located.
 FIG. 2 illustrates another embodiment, wherein the first compartment 2 is
 bored through centrically and said bore is filled with the second
 compartment 3 so that the second compartment is partially encompassed.
 The contact lens care agent is a formed piece having two axes V and H being
 perpendicular to each other, wherein the first compartment (2) is located
 around the first axis H and the second compartment (3) is located around
 the second axis V.
 FIG. 3 illustrates another embodiment, wherein the first compartment 2
 encloses the second one 3 completely.
 Initially, the user fills the aqueous disinfecting solution, preferably a
 3% hydrogen peroxide solution, into a cleaning device known per se and
 adds the contact lens care agent according to the invention and the
 contact lenses to be cleaned and disinfected. The disinfecting solution
 will dissolve the compartment containing subtilisin so that the removal of
 any deposits existing on the lens begins. Simultaneously, the contact lens
 is disinfected by the action of the disinfectant H.sub.2 O.sub.2.
 Depending on the embodiment also the second compartment, containing the
 agent neutralizing the disinfectant is dissolved more or less
 simultaneously. Due to the higher dissolution rate of the first
 compartment said first compartment will be dissolved completely when the
 second compartment has dissolved only partially within the disinfecting
 solution. Then, the catalase contained within the second compartment is
 further gradually dissolved into the disinfecting solution so that the
 catalase will increasingly cause the decomposition of the hydrogen
 peroxide within said compartment.
 The contact lens care agent according to the invention provides a novel
 contact lens care system. Namely, on consultation with the contact lens
 fitter the user can define an individual cleaning procedure suited to the
 user's situation. Thus, e.g., if only moderate contaminations are present
 it is possible to perform the conventional disinfection on two successive
 days, whereas the contact lens care agent according to the invention is
 added at the third day in order to avoid performing the protein cleaning
 every day. Likewise, if heavier contaminations are present, removal of
 protein deposits can be effected on every other day using the contact lens
 care agent according to the invention. The contact lens care agent
 according to the invention is administered, e.g., in the form of blister
 packs, wherein in that case also tablets containing disinfectant
 neutralizers are offered. For example, there can be offered a blister pack
 offering, beginning with the contact lens care agent according to the
 invention in the form of tablets, e.g., two tablets which do not contain
 the agent, in particular the protease, for removing metabolic deposits,
 e.g., protein deposits. Only on the fourth day the blister pack will
 provide the contact lens care agent according to the invention, again
 followed by two tablets containing only the neutralizer.
 The contact lens care agent according to the invention may contain the
 materials contained within the compartments also in the form of granulate,
 the compartments being designed, e.g., as capsules.
 It may be preferred to perform the removal of the hydrogen peroxide not
 completely by defining the container volumes variably. With that, a
 residue of hydrogen peroxide will remain in the storage solution or
 cleaning solution. The advantage of the variability of the hydrogen
 peroxide volume to be employed is that during a longer storage period
 correspondingly more H.sub.2 O.sub.2 containing solution can be provided
 so that decomposition will occur not completely and a residual content of
 H.sub.2 O.sub.2 remains within the solution in order to provide a
 persistent bactericide and/or bacteriostatic environment within the
 solution. In particular, this residual content of hydrogen peroxide can be
 up to 0.8% by weight and, if required, less, e.g., up to 0.2% by weight.
 This offers the advantage that in particular during a longer storage of
 the lens within the storage solution there will be no subsequent microbic
 contamination as a continued bactericide and/or bacteriostatic environment
 will be present.
 The agent can be adjusted such that there remains no or only a very low
 value of stimulus which remains controllable even with a very pronounced
 sensitivity of the eyes by a very short-time rinsing using appropriate
 commercial sodium chloride rinsing solutions.