Patent ID: 6572894
Filing Date: 2003-06-03
Classification: A61K,A61P,B01J,Y10S

Abstract:
A process for the production of morphologically uniform microcapsules that comprise biodegradable polymers or copolymers and contain at least one peptide, protein or other water-soluble, biologically active substance as the active ingredient, by an induced phase transition process which comprises:(a) dissolving a polymer selected from the group consisting of polyamides, polyanhydrides, polyorthoesters, polyacetates, polylactones, polyorthocarbonates, polyesters, and polyesters of hydroxycarboxylic acids or block copolymers of polyesters of hydroxycarboxylic acids and polyethylene glycol, in a halogen-free solvent that is partially water-miscible; (b) dispersing therein a solution of the active ingredient to form a W/O emulsion; (c) adding an aqueous solution that contains a surfactant or a mixture of surfactants to this W/O emulsion wherein the surfactant solution is present in an amount less than 60% v/v; (d) removing the solvent, thus forming the microcapsules; and (e) optionally, removing residual solvent, unencapsulated active ingredient and/or surfactant.