醋酸钙梯度法制备阿魏酸脂质体的研究及体外评价

 目的采用醋酸钙梯度法制备阿魏酸脂质体,考察其制备工艺及理化性质,进行体外释放度及稳定性评价。方法以包封率为指标,考察阿魏酸脂质体胆固醇含量、脂药比、孵育时间、孵育温度、钙离子浓度等因素对包封率的影响。评价其粒径、Zeta电位、体外释放、稳定性。采用冷冻蚀刻电镜观察其显微结构。结果磷脂-胆固醇比例为0.5,脂药比为26,钙离子浓度120 mol·L^-1,孵育条件为37℃,30 min制备的脂质体包封率达80.2%,粒径152 nm。荷电脂质体粒径增加,Zeta电位升高。载药脂质体Zeta电位降低,粒径无变化。体外5 h释放80%。30 d内包封率及粒径均无显著变化。结论通过工艺和处方考察优选出最佳制备条件,制得的阿魏酸脂质体为单室结构,包封率高,稳定性好。

Preparation of Ferulic Acid Liposomes by Calcium Acetate Gradient Method and Its Evaluation in Vitro

OBJECTIVE To evaluate the quality,physical and chemical properties,stability and release of ferulic acid(FA) liposomes prepared by calcium acetate gradient method.METHODS The effect of cholesterol content,lipid-drug ratio,incubation time and temperature,and calcium acetate concentration on entrapment efficiency was studied.The average size distribution,Zeta potential,release in vitro and stability of FA liposomes were determined.The structure was identified by Freeze-fracture electron microscopy.RESULTS The entrapment efficiency was 80.2% with PC-Ch molar ratio 0.5,lipid-drug molar ratio 26,calcium acetate concentration 120 mol·L^-1,at 37 ℃ for 30 min.The average size was 152 nm.Charge had great influence on average size and the Zeta potential.Zeta potential decreased with the loading of drug.80% Ferulic acid released from liposomes within 5 h and FA liposomes was stable during 30 days.CONCLUSION The optimized conditions were obtained with high entrapment efficiency and good stability.Unilamellar vesicles were presented in the micrographs.