Patent ID: 7033608

Claim:
A process for preparing controlled release microcapsule formulations characterized by burst-free, sustained, programmable release of biologically active agents comprising: Dissolving biodegradable poly (lactide/glycolide), polymer in a form of uncapped/end-capped blend in a ratio of from 50/50 to 1/99 in methylene chloride, and dissolving a biologically active agent or active core in water; adding the aqueous layer to the polymer solution and emulsifying to provide an inner water-in-oil (w/o) emulsion; stabilizing said inner w/o emulsion in a solvent-saturated aqueous phase containing an oil-in-water (o/w) emulsifier; emulsifying said inner w/o emulsion in an external aqueous layer containing oil-in-water emulsifier to form a ternary emulsion; and stirring the resulting water-in-oil-in-water (w/o/w) emulsion for sufficient time to remove said solvent to harden microcapsules, and rinsing the hardened microcapsules with water and lyophilizing said hardened microcapsules.