Patent ID: 6596305
Filing Date: 2003-07-22
Classification: A61K,Y10T

Abstract:
A method for producing a pharmaceutical composition comprising a liposome population having a predetermined mean particle size comprising combination of a water-miscible organic solvent and a lipid according to the steps of:(a) preparing a first solution comprising the lipid, the solvent and an aqueous phase and then removing the solvent so as to form liposomes, wherein the concentration of the solvent is from about 0.5% to less than about 10% by volume of the solution; (b) preparing a second solution comprising the lipid, the solvent and an aqueous phase and then removing the solvent so as to form liposomes, wherein the concentration of the solvent is about 10% by volume of the solution; (c) preparing a third solution comprising the lipid, the solvent and an aqueous phase and then removing the solvent so as to form liposomes, wherein the concentration of the solvent is from about 10 to 15% by volume of the solution; (d) determining the mean particle sizes of liposomes prepared in accordance with steps (a), (b) and (c); (e) comparing the mean particle sizes with the solvent concentration used; (f) selecting an organic solvent concentration corresponding to a desired mean particle size; and (g) preparing a solution comprising the lipid, solvent and an aqueous phase, wherein the organic solvent concentration is selected according to step (f), wherein the lipid comprises egg phosphatidylcholine and the solvent concentration in a solution is at most about 15%.