Patent ID: 6726925
Filing Date: 2004-04-27
Classification: A61K,A61P

Abstract:
A liposome, comprising a gel-phase lipid bilayer membrane having a phase transition temperature, and an active agent,wherein the gel-phase lipid bilayer membrane comprises: (a) one or more phospholipids selected from the group consisting of phosphatidyl cholines, phosphatidyl glycerols, phosphatidyl inositols, and phosphatidyl ethanolamines, wherein the one or more phospholipids have two acyl groups; and (b) one or more lysolipids selected from the group consisting of monoacylphosphatidyl cholines, monoacylphosphatidylglycerols, monoacylphosphatidylinositols, and monoacylphosphatidylethanolamines, wherein the one or more lysolipids have one acyl group; and wherein the active agent is selected from the group consisting of a pharmacologically active agent or a diagnostic agent; and wherein the phase transition temperature is 39 to 45Â° C., and, wherein the amount of the one or more lysolipids in the gel-phase lipid bilayer membrane is sufficient to increase a first percentage of active agent released from the liposome at the phase transition temperature, compared to a second percentage of active agent released in the absence of the one or more lysolipids.