METHOD FOR PRODUCING BIOSOLUBLE COPOLYMERS OF ACRYLAMIDE, VINYLPYRROLIDONE AND ALKYLACRYLATE Russian patent published in 2009 - IPC C08F220/56 

FIELD: chemistry.

SUBSTANCE: invention refers to method for producing biosoluble copolymers of medical acrylamide, vinylpyrrolidone and alkylacrylate to be used for eye medicated film manufacturing. Method consists in radical copolymerisation of acrylamide, vinylpyrrolidone and alkylacrylate in ratio as follows, wt %: acrylamide 50-70, vinylpyrrolidone 15-25, alkylacrylate 15-25. Method includes the procedures as follows. At first water, initiator, acrylamide, vinylpyrrolidone are charged in amount 70-90 % of total vinylpyrrolidone volume. The mixture is heated up to temperature 70-90°C and within 0.5-1 hours stirred vinylpyrrolidone mixture in amount 10-30 wt % of total vinylpyrrolidone, initiator and alkylacrylate volume is ntroduced. Total monomer concentration in the reaction mixture is 5-30 wt %. Within 2-3 hours the mixture is exposed to the specified temperature. Hydrogen peroxide is added in amount 0.1 to 2 wt % of total monomer weight with additional stirring at polymerisation temperature within 1-3 hours. Further the reaction mass is cooled to temperature 30-45°C. Acetone is added to form coacervate copolymer solution. Mixed water - acetone are decanted. Chloroform is added in volumetric ratio coacervate solution - chloroform 1:0.5 to 1:2, and stirred. After that chloroform is separated, water is added to copolymer concentration 10-35 wt %. While stirring acetone is added in volumetric ratio solution - acetone 1:2 to 1:4. Then sediment is filtered, and copolymer is dried at temperature 80-100°C within 2-6 hours.

EFFECT: making of high yield copolymer of fast swelling capacity and solubility in aqueous environments, formability to viscous solutions, prolong drug release.

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