利福平/乳酸-乙醇酸共聚物缓释微球制备与体外释药性能研究

Preparation of RFP / PLGA Microspheres and Its Drug Release Properties in Vitro

目的制备利福平/聚乳酸-羟基乙酸缓释微球,观察聚合物缓释微球的理化性质,探索利福平(rifampicin,RFP)体外释放规律。方法以高分子材料乳酸-乙醇酸共聚物(PLGA)作为载体,采用复乳-溶剂挥发法(W-O-W)制备RFP/PLGA缓释微球;光学显微镜及扫描电子显微镜观察RFP/PLGA微球特征;高效液相色谱法(HPLC)检测并计算RFP/PLGA微球的载药量、包封率;HPLC检测RFP/PLGA缓释微球在磷酸盐缓冲液(PBS)中不同时段释放量及其累计释放度,拟合缓释曲线。结果 RFP/PLGA微球缓释微球呈圆形或椭圆形,表面有微孔且凹凸不平,微球间无粘连;微球平均粒径为(7.19±0.4)μm;载药量为(11.54±0.15)%,包封率为(72.35±0.46)%;突释期内累计释放度达42%,到12d时累计释放度达62%。结论 RFP/PLGA微球具有一定的缓释效果,是一种适宜的抗结核药物运载系统。

Objective To prepare Rifampin / Poly lactic- co- glycolic acid sustained release microspheres using compound emulsion solvent evaporation technique,and to observe the physical and chemical properties and the drug release behavior in vitro. Methods PLGA was used as carrying agent and RFP / PLGA microspheres was prepared by compound emulsion solvent evaporation technique. The characteristics of RFP / PLGA polymer hydrogel microspheres were observed by light microscope and scanning electron microscopy. Drug loading as well as encapsulation efficiency was detected by high performance liquid chromatography( HPLC).The amount of release in different periods and its cumulative release rate were tested by HPLC. Excel software was used to fit the curve of drug release in vitro and establish the equation of the curve. Results The RFP-PLGA microspheres were found balling little irregular,round or oval,bristle,uneven surface,adhered to each other under SEM. The average particle size was( 7. 19 ± 0. 4) μm while drug loading was( 11. 54 ± 0. 15) %,and encapsulation efficiency was( 72. 35 ± 0. 46) %. The cumulative release rate was 62% at 12 days. Conclusion With perfect slow release effect,RFP / PLGA microsphere is a kind of ideal anti- TB drugs slow release system.