PREPARATION AND STABILITY OF LIPOSOME-ASSOCIATED HARRINGTONINE

Harringtonine was incorporated into positively charged liposomes by using the REV (Reverse-phase-evaporation) method. It was shown that the percentage encapsulation of harringtonine in liposomes was greatly affected by ionic strength, evaporation temperature, lipid concentration and the amount of cholesterol. A thick harringtonine liposomal suspension with higher encapsulation and stability has been screened and devised. Its structure, size, percentage of encapsulation, degree of lipid oxidation and tendency to cause haemolysis were examined at 10℃ and 40℃. The suspension showed no change when stored at 10℃ for five months; after storage at 40℃ for one month a tendency to cause haemolysis was observed. After two months of storage some changes in size and structure were found. The results indicate that thick harringtonine liposomes are stable in physical and chemical properties under appropriate conditions (eg at 10℃ and under N₂) in a limited time (five months).