目的制备高包封率的盐酸去氢骆驼蓬碱脂质体。方法处方前研究测定了药物在不同pH值缓冲液中的溶解度和表观油水分配系数;采用pH梯度进行主动载药。超滤法分离脂质体与游离药物,测定包封率,考察了外水相pH值、孵育温度、药脂比对包封率的影响。结果随pH值的增大,盐酸去氢骆驼蓬碱的溶解度降低,表观油水分配系数增大;采用主动载药法,包封率随脂质体内外相pH梯度的减少而降低,受孵育温度的影响不大,在药脂比小于1∶5时脂质体包封率达到80%以上。结论主动载药法可制得包封率较高的去氢骆驼蓬碱脂质体。

Objective To prepare a harmine hydrochloride liposome formulation with high encapsulation efficiency. Methods Preformulation investigation was carried out to obtain the drug physicochemical properties such as solubility and lgD in buffers of different pH value. Harmine hydrochloride was encapsulated into liposomes by active loading method. Encapsulation efficiency of liposomes was determined after the free drug was separated from liposome by ultrafiltration. The influence factors on the encapsulation efficiency including drug-lipid weight ratio, incubation temperature, pH value of external water phase were investigated. Results As the pH value increasing, the solubility of harmine hydrochloride was decreased, while the apparent oil-water distribution coefficient was increased. By active loading method, the encapsulation efficiency could be over 80% when the drug to lipid weight ratio was under 1∶5. The pH gradient between intervesicle and intravesicle obviously influenced the encapsulation efficiency, while incubation temperature had little effect on encapsulation efficiency. Conclusion Active loading is suitable for preparing harmine hydrochloride liposome with high encapsulation efficiency.