Patent ID: 8697127
Filing Date: 2014-04-15
Classification: A61K,A61P

Abstract:
1. A method for preparing a polymeric microsphere, including: (a) preparing an oil-in-water (O/W), oil-in-oil (O/O) or water-in-oil-in-water (W/O/W) emulsion including a polymer compound, a drug, a water-insoluble organic solvent and a dispersion solvent and (b) adding to the emulsion prepared in (a) a base solution or an acid solution to remove the water-insoluble organic solvent from the emulsion, wherein the base or the acid solution converts, through hydrolysis, the water-insoluble organic solvent in an aqueous phase of the emulsion into a water-soluble solvent; wherein the water-insoluble organic solvent in an oil phase of the emulsion diffuses into the aqueous phase, subsequently followed by conversion through hydrolysis into a water-soluble solvents, thereby hardening of an emulsion droplet into the polymeric microsphere; wherein the polymer compound is one selected from the group consisting of polyactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide (PLGA), polyphosphazine, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, a copolymer of lactic acid and caprolactone, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, a copolymer of lactic acid and amino acid, and a mixture thereof; and wherein the water-insoluble organic solvent is one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl formate, ethyl formate, isopropyl formate, propyl formate, butyl formate, methyl dichloroacetate, methyl chloroacetate, ethyl chloroacetate, ethyl dichloroacetate, methyl fluoroacetate, methyl difluoroacetate, ethyl fluoroacetate, ethyl difluoroacetate, maleic anhydride, acetic anhydride, propionic anhydride, phosphoric anhydride, acetamide, propionamide, butylamide and carboxylamide.