ZHAO Yan2�� DENG Yi-hui1*�� XIAO Li-ying1�� LEI Jie-jie1�� WANG Shao-ning1
1.School of Pharmacy�� Shenyang Pharmaceutical University�� Shenyang 110016�� China��2.Department of Pharmaceutics, College of basic Medical Sciences, China Medical University, Shenyang 110001, China
Abstract��
OBJECTIVE To prepare vincristine sulfate liposomes by active loading method, and study the influence of different factors on the entrapment efficiency.METHODS Cation exchange resin was used to separate the free vincristine sulfate from the liposomes. The entrapment efficiency was determined. The influences of various factors, including incubation temperature, the basic solution of external water phase, drug-to-lipid ratio, long-circulating materials and the methods of prepartion, on the entrapment efficiencies were investigated.RESULTS The entrapment efficiency was enhanced by the increased temperature and the decreased drug-to-lipid ratio. Na2HPO4 was suitable for adjusting pH value in external water phase. The entrapment efficiencies with pH transmembrane gradients and ammonium sulfate transmembrane gradients were 86.9% and 70.8%,respectively, while up to 92.8% and 97.6% with the incorporation of CHS-PEG2000(methoxypolyethyene glycol 2000 cholesteryl succinate) in liposomal formulation.CONCLUSION Active loading method is suitable for preparing vincristine sulfate liposomes. The factors of temperature,basic solution and drug-to-lipid ratio can influence liposomal entrapment efficiencies prominently.
ZHAO Yan,
DENG Yi-hui,
XIAO Li-ying etc
.Study on influencing factors in preparation of vincristine sulfate liposomes by active loading method [J] Chinese Pharmaceutical Journal, 2005,V39(22): 1717-1719
2005, Vol. 39 
