[The preparation and stability of liposome-encapsulated Ara-A]

This paper uses several preparation methods, such as thin-film, reverse-phase evaporation and freeze-thawing methods, and also compares encapsulation percentage of Ara-A in liposome (EN%) of these methods. The best operational conditions of preparing liposome-encapsulated Ara-A are explored. A higher EN%, about 50%, which is ten times that reported in foreign literature, is obtained by using improved freeze-thawing method, and this method is easy to operate and repeatable. At the same time, the physical and chemical stabilities of the liposome-encapsulated Ara-A were observed. The result shows that there are no distinct changes in shape, size distribution of liposome, and EN% as well as Ara-A contained in liposome by means of sterilization at 100 degrees C for 30 minutes. Accelerating test at a constant temperature indicates that liposome-entrapped Ara-A has certain chemical stability.