中链脂肪酸-维生素C冻干脂质体的制备研究

Study on preparation and characteristics of medium chain fatty acids-Vitamin C freeze-dried liposomes

以脂溶性药物中链脂肪酸(MCFAs)和水溶性药物维生素C(Vit.C)为模型药物,采用复乳-高压法制备中链脂肪酸-维生素C复方脂质体,并用冷冻干燥技术制备成固体脂质体。通过研究脂质体的形态、粒径分布和包封率,对预冻温度、预冻时间、干燥时间、适宜的冻干保护剂种类、冻干保护剂与卵磷脂的质量比分别进行单因素考察。优选脂质体适宜的预冻温度为-80℃,预冻时间为5h,总干燥时间48h,适宜的冻干保护剂为蔗糖,蔗糖与卵磷脂的质量比为1.5∶1。最优冻干工艺条件下制得的中链脂肪酸-维生素C复合脂质体的维生素C包封率为62.25%,MCFAs包封率为46.30%,平均粒径为115.5nm。并考察了复方脂质体冻干前后粒径、Zeta电位、颗粒形态变化,发现粒径和Zeta电位变化不大,表明复方脂质体具有较好的物理稳定性。

The medium chain fatty acids-vitamin C（MCFAs-Vit.C）complex liposomes were prepared by double emulsion-high pressure microfluidization with lipophilic drugs medium chain fatty acids（MCFAs）and hydrophilic drug vitamin C（Vit.C）as the core material,and solid liposomes were further made by lyophilization.The effects of pre-freezing temperature,pre-freezing time,total freeze-dried time,types of lyoprotectant and the mass ratio of lyoprotectant to lecithin were investigated by taking liposomes shape,size distribution and drugs entrapment efficiency as indexes.The suitable preparation conditions of liposomes were as follows：pre-freezing temperature-80℃,pre-freezing time 5h,total freeze-dried time 48h,sucrose as suitable lyoprotectant,the ratio of sucrose to lecithin（w/w）1.5∶ 1.Under these conditions,the MCFAs-Vit.C complex liposome had 46.30% MCFAs encapsulation efficiency and 62.25% Vit.C encapsulation efficiency with a mean particle size of 115.5nm.In addition,the changes of particle size,Zeta potential and morphology of liposomes before and after lyophilization were studied.The results showed that the complex liposome had better physical stability with little changes in particle size and Zeta potential.