Patent ID: 11925708
Assignee: JIANGNAN UNIVERSITY
Field: Pharmaceuticals (Chemistry)
Classification: CPC A  Y | IPC A  B  C

Claim 0:
1. A method for making modified polyvinyl alcohol embolic microspheres comprising:
1) putting polyvinyl alcohol in organic solvent A and stirring for preparing a polyvinyl alcohol solution; dissolving acryloyl chloride or butenoyl chloride in organic solvent B for preparing an acyl chloride solution;
2) adding an acid binding agent to the polyvinyl alcohol solution, dropping the acyl chloride solution into the polyvinyl alcohol solution, stirring for 3-5 hours at room temperature, then raising the temperature to 45-50° C., and stirring for additional 1-2 hours, cooling the reaction solution that results to room temperature, pouring the reaction solution into excess absolute ethanol for precipitating the polymer, then filtering, washing the polymer with absolute ethanol, drying the polymer to a constant weight in a drying oven, and obtaining allyl polyvinyl alcohol or butyryl polyvinyl alcohol;
3) weighing the dried allyl polyvinyl alcohol or butyryl polyvinyl alcohol and putting it in water with stirring to dissolve it; then dissolving taurine in water to make a taurine solution, adding the taurine solution to the allyl polyvinyl alcohol solution or butyryl polyvinyl alcohol solution, adjusting the pH value to 9-11, stirring and reacting under temperature of 45-50° C. for 40-48 hours, then cooling the reaction solution that results to room temperature, slowly pouring the reaction solution into excess absolute ethanol for precipitating the product, filtering and washing the product with absolute ethanol, and drying the product in a drying oven to a constant weight to obtain functionalized modified polyvinyl alcohol;
4) adding 3-5% by volume of a non-ionic surfactant to an oil for preparing an oil phase solution with even stirring; dissolving the functionalized modified polyvinyl alcohol in ionized water to prepare a solution with a functionalized modified polyvinyl alcohol concentration of 60-100 g/L, and then pouring it into the oil phase solution slowly for emulsification, adding a cross-linking agent when Tyndall phenomenon is observed, after 4-6 hours, demulsifying the emulsion with ethanol to obtain solid microspheres, filtrating and washing the microspheres with ethanol, and then drying to obtain modified polyvinyl alcohol embolic microspheres; wherein the organic solvent A in step 1) is one of dimethyl sulfoxide, N, N-dimethylacetamide or formamide; and the organic solvent B in step 1) is one of dichloromethane, trichloromethane or dichloroehane.