丹参素脂质体的制备及体外释放度研究

Preparation and Drug Release in vitro of Danshensu Liposomes

目的：制备丹参素脂质体并考察其体外释放度。方法：采用逆相蒸发法制备丹参素脂质体,以包封率为指标,通过正交试验考察大豆卵磷脂浓度、大豆卵磷脂与丹参素药脂比和水相p H值。透射电镜观察所制备脂质体的形态和粒径,利用HPLC测定丹参素含量,透析法比较丹参素脂质体和游离丹参素的体外释放度。结果：最佳制备工艺：磷脂浓度为40 mg·ml-1,药脂比为1∶10,水相p H为6.6。制备的丹参素脂质体为圆整球形,平均粒径（174±36）nm,平均包封率38.9%。丹参素浓度范围在2.0-20.0 mg·L-1的线性关系良好（r=0.998 4）,丹参素脂质体的体外释放度比游离丹参素慢,能达到24 h缓释。结论：采用逆相蒸发法制备的丹参素脂质体粒径大小均匀,具有一定的缓释效果。

Objective：o prepare Danshensu liposomes and investigate drug release characteristics in vitro. Methods： Danshensu liposomes were prepared by a reverse-phase evaporation method. The encapsulation efficiency was used as the index, an orthogonal test was adopted to investigate the effect of concentration of soybean lecithin, ratio of lipid-Danshensu and pH value of solution on the preparation procedure of Danshensu liposomes. The particle size of the liposomes was also investigated by a transmission electron micro-scope （ TEM） . The concentration of Danshensu was determined by HPLC, and the difference of release characteristics in Danshensu li-posomes and Danshensu solution was measured by a dialysis method. Results：The optimum preparation technology was as follows：the concentration of soybean lecithin was 40 mg·ml-1 ,the ratio of drug-lipid was 1： 10,and the pH value of solution was 6. 6. The mor-phology of the prepared liposomes showed spheric structure with uniform diameter, and the average particle size was （ 174 ± 36 ） nm and the encapsulation efficiency was 38. 9%. The linear range of Danshensu was 2. 0-20. 0 mg·L-1（r=0. 9984）. The drug release of liposomes in vitro was slower than that of free Danshensu solution in 24 h. Conclusion：Danshensu liposomes with fine morphology have sustained release property.