Chemistry: molecular biology and microbiology – Process of utilizing an enzyme or micro-organism to destroy... – Cleaning using a micro-organism or enzyme
Reexamination Certificate
1999-10-26
2001-01-30
Gehman, Bryon P. (Department: 3728)
Chemistry: molecular biology and microbiology
Process of utilizing an enzyme or micro-organism to destroy...
Cleaning using a micro-organism or enzyme
C134S042000, C134S901000, C206S005100, C422S028000, C422S030000, C510S114000
Reexamination Certificate
active
06180393
ABSTRACT:
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.
REFERENCES:
patent: 4568517 (1986-02-01), Kaspar et al.
patent: 4748992 (1988-06-01), Giefer
patent: 4863627 (1989-09-01), Davies et al.
patent: 5011661 (1991-04-01), Schafer et al.
patent: 5312588 (1994-05-01), Gyulai et al.
patent: 5384091 (1995-01-01), Rontome et al.
patent: 5556480 (1996-09-01), Rontome et al.
patent: 5723096 (1998-03-01), Bruun-Jensen
patent: 5759540 (1998-06-01), Nielsen
patent: 5766931 (1998-06-01), Cook et al.
patent: 5897833 (1999-04-01), Hunt et al.
patent: 5919698 (1999-07-01), Sorensen et al.
patent: 6022732 (2000-02-01), Bakhit et al.
patent: 0 209 071 (1987-01-01), None
patent: 0 219 220 (1987-04-01), None
patent: WO 91 12826 (1991-09-01), None
patent: WO 97 11722 (1997-04-01), None
Collard & Roe PC
Gehman Bryon P.
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