The Liposome Company, Inc.

Sharon S Carpenter-Green

Alan L Weiner

Mircea C Popescu

Robert P Lenk

Michael W Fountain

A novel oil and water emulsion useful for delivery of a bioactive agent is disclosed. The emulsion comprises a first HLB requirement amount of surfactant dioleoyl phosphatidylethanolamine. In particular embodiments the emulsion includes a secondary surfactant other than dioleoyl phosphatidylethanolamine except in the limiting case wherein the HLB requirement is the HLB value of dioleoyl phosphatidylethanolemine in which case the the HLB requirement amount of a secondary surfactant is 0. By appropriate selection of dioleoyl phosphatidylethanolamine to secondary surfactant ratios, it is possible to prepare emulsions for pharmaceutical delivery of a bioactive agent using an oil phase having a required HLB value up to about 17.4. Above a required HLB value of about 17.4. dioleoyl phosphatidylethanolamine may be used to reduce the amount of secondary surfactant required to form an emulsion.

Emulsions

This invention encompasses new and substantially improved methods and compositions for delivery of therapeutic agents to specifically chosen body sites. Conjugation of fibronectin to bioactive agents or to lipids or to liposomes which entrap the bioactive agents permits immobilization of the bioactive agent when administered at collagen-, heparin-, hyaluronic acid-, fibrin/fibrinogen-, or ganglioside-rich sites. Covalent conjugation is achieved by two methods: (1) the enzymatically catalyzed cross-linkage of fibronectin to an amine containing compound, and (2) by a modified NHS method which permits formation of peptide bonds between fibronectin and lipid compounds.

Localized delivery using fibronectin conjugates

A novel oil and water emulsion useful for delivery of a bioactive agent is disclosed. The emulsion comprises a first HLB requirement amount of surfactant dioleoyl phosphatidylethanolamine. In particular embodiments the emulsion includes a secondary surfactant other than dioleoyl phosphatidylethanolamine except in the limiting case wherein the HLB requirement is the HLB value of dioleoyl phosphatidylethanolamine in which case the HLB requirement amount of a secondary surfactant is 0. By appropriate selection of dioleoyl phosphatidylethanolamine to secondary surfactant ratios, it is possible to prepare emulsions for pharmaceutical delivery of a bioactive agent using an oil phase having a required HLB value up to about 17.4. Above a required HLB value of about 17.4. dioleoyl phosphatidylethanolamine may be used to reduce the amount of secondary surfactant required to form an emulsion.

Compositions and methods for maintaining reservoirs of bioactive agents by sequestering the reservoir in a gel matrix are described. In particular, liposomes containing an entrapped bioactive agent are sequestered in a gel matrix. The resulting liposome-gel compositions may be used in vivo or in vitro to provide for sustained release of the bioactive agent. The gel matrix inhibits the dispersion and clearance of the sequestered liposomes without interfering with the ability of the liposomes to release the entrapped bioactive agent. Furthermore, the rate of release of the bioactive agent from the liposome-gel compositions may be varied by altering the composition of the liposomes and/or gels.

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Cranbury, NJ, United States of America

Sharon S Carpenter-Green