Encapsulation of a Water Soluble Drug in a Liposome Preparation: Removal of Free Drug by Washing

Multilamellar and unilamellar vesicles were generated by using phosphatidylcholine-phosphatidylglycerol-cholesterol formulation. Liposomes were washed with normal saline to remove non-encapsulated drug. The result of the washing technique was the removal of free (non-encapsulated) drug, in turn improved the percent drug encapsulation in washed liposome preparation. Liposome vesicles were characterized by size, lamellarity, and percent drug encapsulation. Vesicle size was assessed by light scattering, lamellarity by electron microscopy and drug concentration by HPLC techniques.