PROCEDURE FOR PREPARATION OF LIPID VESICLES (LIPOSOMES) USING THE COACERVATION (PHASE-SEPARATION) TECHNIQUE

The preparation of lipid vesicles using simple coacervation is describ ed in detail. The optimal coacervation conditions for the formation of lipid vesicles by the triangular phase diagram of the lipid-alcohol-w ater system were examined. Four different alcohols (methanol, ethanol, n-propanol, and 2-propanol) were used as a lipid solvent, and deioniz ed, distilled water was used as a poor solvent for the lipids. The lam ellarity and size homogeneity of the resulting lipid vesicles were obs erved by freeze-fracture electron microscopy and scanning electron mic roscopy, respectively, using a specific fixation technique with malach ite green. The majority of vesicles formed by methanol as a lipid solv ent appeared to be large and unilamellar, ranging from 100 to 1000 nm in diameter. However, when the vesicles were prepared using ethanol, c oncentric lamellae of multilamellar vesicles were recognizable. On the other hand, the use of propanol resulted in lipid vesicles that were homogeneous and unilamellar.