Patent ID: 6471996
Filing Date: 2002-10-29
Classification: A61K,C08G,Y10S,Y10T

Abstract:
A process for making a particulate carrier for the delivery of at least one biologically active material to a host, comprising the steps of:(a) mixing an organic solvent phase comprising an &agr;-hydroxy acid polymer with an aqueous composition comprising dispersed or dissolved biologically active material to form a first water-in-oil emulsion, said &agr;-hydroxy acid polymer having a molecular weight of about 5,000 to about 40,000 daltons and having the general formula: â€ƒwherein: R1, R2 and R5 are selected independently and are selected from the group consisting of H, linear or branched alkyl groups; R3 and R4 are H; R6 is H; X is selected from the group consisting of an O or S group; and x and y are integers such that at least 95% of the polymer is comprised of &agr;-hydroxy acid residues; (b) dispersing the first water-in-oil emulsion into an aqueous detergent phase to form a second water-in-oil-in-water double emulsion; (c) removing water from the second double emulsion to form microspheres; and (d) collecting the microspheres and having said biological material entrapped therein.