甘草酸二铵脂质体的制备及其性质的研究

Preparation and characterization of diammonium glycyrrhizinate liposomes

目的:研究甘草酸二铵阳离子脂质体的制备方法和脂质体的性质。方法:采用均匀设计筛选最佳处方,逆相蒸发法制备甘草酸二铵脂质体;葡聚糖凝胶柱法测定其包封率;用透射电镜观察脂质体的外观形态,马尔文测定仪测定脂质体的粒径和Zeta电位;并用溶出度第3法考察了脂质体的释放规律。结果:制得脂质体的包封率约为(56±1．54)%(n=3);脂质体的形态为粒径均匀的球形或近球形,粒径为(183±9)nm(n=3),Zeta电位为(22．8±6)mV(n=3);脂质体的体外释药符合Higuchi方程;具有较好的稳定性。结论:采用逆相蒸发法,添加十八胺可制得具有较高包封率及稳定性的甘草酸二铵阳离子脂质体,制得脂质体的体外释放具有缓释特点。

Objective：To prepare and characterize diammonium glycyrrhizinate （DG） cationic liposomes. Methods：Liposomes were prepared by reverse-phase evaporation technique. The uniform design with computer-based optimization was utilized to optimize the formulation and preparation procedure of DG liposomes. The encapsulation efficiency was determined by Sephadex-G50 chromatography. The morphological examination of DG liposomes was performed using transmission electron microscopy （TEM）. The particle size and Zeta potential of the liposomes were measured by Zetamaster. The release rate of DG from liposomes was tested by the third method of dissolution test under Chinese pharmacopoeia （2005 Edition, Part 11 ）. Results：The liposomes with spherical or ellipsoidal shape and better stability featured the encapsulation efficiency of （56 ± 1.54）% （n = 3 ） , the mean particle size of （ 183 ± 9） nm （n = 3） , and Zeta potential of （22.8 ± 6） mV （ n = 3 ）. The release kinetics in vitro obeyed Higuchi＇ s equation. Conclusion：By reverse-phase evaporation technique and complex of lipid membrane with octadecylamine, the encapsulation efficiency and stability of DG cationic liposomes could be increased. The liposomes featured a sustained release of DG in vitro.