Patent ID: 6132766
Filing Date: 2000-10-17
Classification: A61K,A61P,Y10S

Abstract:
A multivesicular liposome having multiple non-concentric chambers with internal membranes distributed as a network throughout, produced by a method comprising the steps of:(a) forming a water-in-oil emulsion from two immiscible components, the two immiscible components being:1) a lipid component comprising at least one organic solvent, at least one amphipathic lipid, and at least one neutral lipid lacking a hydrophilic head group, and2) a first aqueous component;said water-in-oil emulsion further comprising:3) non-hydrohalic acid in a concentration range from about 0.1 mM to about 0.5 M, wherein the concentration is selected to provide controlled release of the biologically active substance in 4) from the liposome, and4) at least one biologically active substance;said non-hydrohalic acid and said biologically active substance being independently incorporated into the lipid component, the first aqueous component, or both;(b) mixing the water-in-oil emulsion containing the non-hydrohalic acid with a second aqueous component to form solvent spherules; and thereafter(c) removing the organic solvent from the solvent spherules to form multivesicular liposomes.