Patent ID: 7901709

Claim:
A method for loading active agents into liposomes, comprising: (a) providing a liposome comprising a gel-phase lipid bilayer, said lipid bilayer comprising dipalmitoylphosphatidylcholine (DPPC) and monostearoylphosphatidylcholine (MSPC), wherein the DPPC and the MSPC are present in the lipid bilayer in a molar ratio ranging from about 95:5 to about 80:20, and wherein said lipid bilayer is present below its phase transition temperature; and (b) exposing the lipid bilayer to an active agent at a temperature below the phase transition temperature of the lipid bilayer to load the liposome interior with the active agent, wherein the active agent is loaded into the liposome at the temperature below the phase transition temperature of the lipid bilayer.