Patent ID: 8883200

Claim:
A process for preparing a microparticulate complex of lipid an nucleic acid, which process comprises: combining a lipid composition comprising cationic and non-cationic lipids, and a nucleic acid component, in an aqueous/organic solvent system comprising water and less than 55% by volume of a water-miscible organic solvent, wherein the aqueous component of the aqueous/organic solvent system has an ionic strength of less than that of about 50 mM NaCl, to form a mixture which is heated to a temperature of from 30° to 80° C., forming a monophasic system wherein the aqueous/organic solvent system is a single liquid phase and wherein the lipid composition and the nucleic acid component are independently molecularly or micellarly soluble in the single liquid phase, and reducing the amount of the organic solvent in the monophasic system so that the microparticulate complex is formed.