THE INFLUENCE OF LIPID-COMPOSITION AND LAMELLARITY OF LIPOSOMES ON THE PHYSICAL STABILITY OF LIPOSOMES UPON STORAGE

The physical stability of the four liposomal systems was determined on storage at 4 and 25 degrees C over a 6-month period. A correlation of the mean volume diameter, zeta potential and pH lead to the conclusio n that stability follows the order of egg lecithin (PC)/cholesterol (C H)/stearylamine (SA) < PC/CH/phosphatidylserine (PS) < bovine brain ce ramides (CM)/CH/palmitic acid (PA)/CS < PC/CH/cholesteryl sulphate (CS ) at 4 degrees C, as well as at 25 degrees C, after a 6-month storage period. Large unilamellar vesicles (REV) proved to be superior to mult ilamellar liposomes (MLV) and dehydration/rehydration liposomes (DRV) systems as far as physical stability was concerned. Instability was ex aggerated in the systems stored at 25 degrees C as compared to storage at 4 degrees C.