Extraction process for producing PLGA microspheres

Abstract

A hybrid evaporation-extraction process for preparing microspheres of a p(DL-lactide-to-glycolide) biodegradable polymer, comprising: a. preparing a lyophilized biologically active material-sucrose matrix; adding acetonitrile solvent to biologically active material-sucrose matrix to form a solution; b. preparing a solution of a biodegradable poly (DL-lactide-co-glycolide) polymer by adding acetonitrile solvent to the polymer; c. adding the biodegradable poly (DL-lactide-co-glycolide) polymer acetonitrile solution to the biologically active material-sucrose acetonitrile solution; d. adding with stirring an oil containing lecithin to the poly (DL-lactide-co-glycolide) polymer-sucrose-biologically active material solution to evaporate acetonitrile and form an emulsion containing microspheres of poly (DL-lactide-co-glycolide) biodegradable polymers; e. adding the emulsion from step d. into a solvent selected from heptane, hexane, pentane or isopropanol; and f. collecting microspheres of poly (DL-lactide-co-glycolide) biodegradable polymers of from 1.0 to about 10.0 micrometers after filtration and washing with a fresh solvent selected from heptane, hexane, pentane or isopropanol.

Dependencies are inferred from the claim text.