鬼臼毒素MPEG修饰脂质体的制备及体外释放的研究

Preparation and in Vitro Release of MPEG-modified Liposomes Containing Podophyllotoxin

目的:制备鬼臼毒素(PPT)MPEG修饰脂质体(PPT-MPL),以及考察PPT-MPL体外释放行为。方法:合成甲氧基聚乙二醇磷脂酰乙醇胺(MPEG-PE),并用薄膜分散法制备脂质体;以包封率为指标,运用正交试验法设计优化脂质体处方和工艺,采用改进的超滤法测定脂质体的包封率,以及透析法研究体外释放行为。结果:优化后的PPT-MPL平均粒径为(106.20±4.10)nm,包封率为(83.30±2.50)%;加入血浆后PPT-MPL体外释放速率比普通脂质体慢(P<0.05)。结论:该法制备PPT-MPEG修饰脂质体,具有粒径小、包封率高以及明显的缓释效果。

Objective： To prepare MPEG-modified liposomes containing podophyllotoxin （PPT-MPL） and to study their in vitro release behavior. Methods： Methoxy-poly（ethylene glycol）-phosphatidylethanolamine （MPEG-PE） was synthesized by two-step process and used as a drug carrier material. PPT-MPL was prepared by thin-film dispersion method. The preparation was optimized by orthogonal design. An improved ultrafiltration method was used to determi- nate liposome entrapment efficiency. In vitro drug release behavior was studied by dialysis method. Results： The aver- age diameter and entrapment efficiency of the optimized liposomes were （106.20±4.10）nm and （83.30±2.50）%, respectively. In presence of plasma podophyllotoxin released more slowly in vitro from the MPEG-modified liposomes than the common liposomes（P〈0.05）.Conclusion： The optimized liposomes have smaller size, higher entrapment efficiency and more sustained release behavior.