Regeneron Pharmaceuticals, Inc.
Sustained Release Formulations Using Non-Aqueous Emulsions

Abstract:

Non-aqueous emulsion methods for producing polymeric or polymer-coated microparticles are provided. One method produces a sustained release microparticle composition by combining protein powder and a polymer into a hydrocarbon solvent to form a non-aqueous first solution and adding the first solution to a second solution, wherein the second solution comprises a fluorocarbon liquid and a fluorosurfactant to form a non-aqueous emulsion comprising multiple emulsion hydrocarbon droplets in the fluorocarbon liquid. The subsequent microparticle hardening process includes the steps of removing the hydrocarbon solvent from the formed emulsion droplets, which can be achieved through evaporation the hydrocarbon at ambient condition under stirring, or accelerated hardening through vacuum, or through adding hydrofluoroester into the fluorocarbon as a cosolvent. Removing the fluorocarbon liquid and washing with extra fluorocarbon liquid to isolate the sustained release microparticles, wherein the sustained release microparticles comprise one or more cores of protein and a cortex of polymer.