Abstract: With a specific aim to preventing the proteolytic enzyme in a preparation for contact lenses containing a proteolytic enzyme from deterioration in the state of aqueous solution, the present invention provides (1) a method of stabilizing a preparation for contact lenses containing a proteolytic enzyme, which comprises formulating the said preparation with a pyrrolidone compound, (2) a process for producing a prepration for contact lenses and (3) a preparation for contact lenses.The preparation according to the present invention can be processed into the liquid or solid preparation form, wherein the liquid preparation can be processed into a one-component type preparation. The liquid preparation as well as the solid preparation, even after being dissolved in water, can maintain the activity of the proteolytic enzyme over a prolonged period of time, and can be used effectively for cleansing and cleaning, preservation and sterilization of contact lenses.

Abstract: A method for stabilizing an agent for contact lenses containing a proteolytic enzyme by adding a surfactant to a solution containing an effective amount of a proteolytic enzyme, the production of a lyophilized agent for contact lenses containing a proteolytic enzyme, which comprises subjecting an aqueous composition containing a proteolytic enzyme to a lyophilizing treatment in the presence of a surfactant, and a lyophilized agent for contact lenses which contains a proteolytic enzyme and a surfactant. The method of the present invention enables stable preservation of a proteolytic enzyme in a liquid form. In addition, cleaning, sterilization and preservation can be simultaneously performed with a single solution, wherein an efficient removal of soil is achieved by only immersing contact lenses in the agent in a solution state. Accordingly, the agent of the present invention is advantageously used with ease by simple handling.

Abstract: A stable aqueous suspension, which is particularly suitable for eyedrops for the treatment of keratopathy and other diseases, containing 5-(3-ethoxy-4-n-pentyloxyphenyl)thiazolidine-2,4-dione can be prepared by adding an acid to an aqueous solution containing one or more members selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropylmethylcellulose, methylcellulose and hydroxyethylcellulose and 5-(3-ethoxy-4-n-pentyloxyphenyl)thiazolidine-2,4-dione and having a pH value of not lower than 8 to adjust said aqueous solution to a pH value of not higher than 7.

Abstract: The object of the invention is to provide a method of cleaning a hard contact lens which is easy to use, excellent in the cleaning effect and then does not affect the lens material disadvantageously. The method of cleaning a hard contact lens is characterized in that the hard contact lens adhered with soil is immersed in a mixture of an aqueous solution of a permanganate salt and an aqueous solution of a mild reducing substance.