Patent ID: 7964211
Filing Date: 2011-06-21
Classification: A61L

Abstract:
1. A method for making absorbable microspheres comprising a copolymer formed from about 88 to 97 mole percent epsilon-caprolactone and about 3 to less than 12 mole percent of glycolide, said copolymer having a crystallinity level ranging from about 30 to 45% and a molecular weight of the copolymer between about 3,000 to 23,000 Daltons; and said microspheres having a distribution of particle sizes from about 30 to 90 microns; comprising the steps of: (a) forming an emulsion of said copolymer, methylene chloride and a polydimethylsiloxane, wherein the copolymer forms microspheres in a microspherical phase and the polydimethylsiloxane forms a continuous phase; (b) extracting the microspherical phase using an excess of decamethylcyclopentasiloxane at a temperature of less than 15 degrees C and above the freezing point to decamethycyclopentasiloxane; and (c) recovering the microspheres by filtration wherein the microspheres have a distinct spherical shape.