Patent ID: 7160551

Claim:
A control led release injectable composition for delivery of a bioactive agent, comprising: a non-aqueous biocompatible solvent; a biodegradable hydrophobic polymer; and an amphiphilic block copolymer comprising at least one segment of poly(ethylene oxide) and at least one segment of poly(propylene oxide); wherein the biocompatible solvent is present in at least about 50 percent by weight of the composition the composition has a viscosity from about 0.1 Pa-s to about 10 Pa-s at 25° C., the amphiphilic block copolymer comprises a di-block copolymer, a tri-block copolymer, a multi-block copolymer or a graft copolymer, a weight ratio of the biodegradable hydrophobic polymer to the amphiphilic block copolymer is from about 10:1 to about 1:1 the composition transforms into a depot upon contact with body fluid, and when the composition is combined with a bioactive agent and administered to an organism, less than about 20% of the bioactive agent is released within 24 hours of administration and less than about 50% of the bioactive agent is released within 200 hours of administration.