Patent ID: 7491409
Filing Date: 2009-02-17
Classification: A61K,A61P

Abstract:
1. A method of encapsulating a bioactive complex in a liposome which comprises the steps of: (a) dissolving at least one amphipathic lipid in one or more organic solvents; (b) combining a first aqueous suspension comprising a nucleic acid with the lipid containing organic solution of step (a) so as to form a water-in-oil emulsion comprising lipid stabilized water droplets containing the bioactive agent; (c) adding a second aqueous suspension comprising a polycation to the emulsion of step (b), so as to form a water-in-oil emulsion comprising the lipid stabilized water droplets of step (b) and lipid stabilized water droplets containing the polycation; (d) incubating the emulsion of step (c) to allow the polycation to contact the nucleic acid thereby forming a complex of the nucleic acid with the polycation within the lipid stabilized water droplets, wherein growth of said complex is limited by the diameter of the lipid stabilized water droplets; and (e) removing the organic solvent from the emulsion of step (d), so as to form liposomes comprising the complexed nucleic acid and the lipid, wherein the liposomes have number average sizes of about 50 to 300 nm, the liposomes encapsulate the complexed nucleic acid; and wherein the nucleic acid to lipid ratio is at least 0.5 μg nucleic acid per μmole of liposomal lipid.