Patent ID: 7550157
Filing Date: 2009-06-23
Classification: A61K

Abstract:
1. A method for preparing a biodegradable polymeric micellar composition comprising the steps of: 1) mixing 5 to 95 wt % of a composition consisting essentially of an amphiphilic block copolymer comprising a hydrophilic poly(alkylene glycol) A block and a hydrophobic polymer B block component and 5 to 95 wt % of a phase separation medium consisting essentially of liquid poly(ethylene glycol) and optionally from 0.1 to 10 wt % water, wherein the hydrophobic biodegradable polymer B block component is a member selected from the group consisting of polylactides, polycaprolactone, copolymers of lactide and glycolide, copolymers of lactide and caprolactone, copolymers of lactide and 1,4-dioxan-2-one, polyorthoesters, polyanhydrides, polyphosphazines, poly(amino acid)s and polycarbonates, and heating the resulting mixture until said block copolymer is dissolved in said liquid poly(ethylene glycol); 2) cooling said solution causing said block copolymer to separate from said phase separation medium thereby causing polymeric micelles formation in said solution by phase separation; 3) dialyzing said solution against an excess of water or an aqueous solution to remove the phase separation medium; and 4) freeze-drying said dialyzed aqueous solution thereby forming a polymeric micellar composition in a powdered state.