PREPARATION METHOD OF DRUG-CONTAINING SUSTAINED RELEASE MICROPARTICLES

The present invention relates to a preparation method of drug-containing sustained release microparticles, the preparation method comprising the steps of: (a) dissolving a biodegradable polymer and a drug in a halogenated alkane solvent to form a drug-containing biodegradable polymer solution; (b) homogeneously mixing the drug-containing biodegradable polymer solution in a continuous phase containing a surfactant to form a dispersed phase; (c) maintaining an emulsion comprising the continuous phase and the dispersed phase at a temperature lower than the boiling point of the halogenated alkane solvent to form microparticles in the continuous phase; (d) primarily drying the microparticles; (e) mixing the primarily dried microparticles with an aqueous alcohol solution, and then maintaining the aqueous alcohol solution at a temperature no less than the boiling point of the halogenated alkane solvent to extract and evaporate the remaining halogenated alkane solvent from the microparticles; and (f) secondarily drying the obtained microparticles to produce drug-containing microparticles. The drug-containing sustained release microparticles prepared in accordance with the preparation method of the present invention minimize the hydrolysis of the biodegradable polymer in the microparticles, while easily removing the halogenated alkane solvent in the microparticles, and are thus capable of exhibiting excellent sustained drug release.