生物降解聚酯包埋利福平缓释微球的制备及释放行为

以生物可降解乙交酯和丙交酯的无规共聚物(PLGA)为载体,将抗结核病药利福平溶解于PLGA的有机溶液中,采用通常乳化-溶剂挥发方法制备了药物缓释微球.研究了影响微球制备的工艺条件.用电子显微镜观察了微球及降解后的表面形态,测定了微球粒径及载药量,评价了载药微球的体外释放行为.结果表明,以质量分数为1%的明胶为稳定剂,制备的微球形态完整,粒径范围为10～30μm,微球中利福平的平均质量分数为24.3%.体外释药时间可以通过高分子的降解速率来调控,本实验的释药时间可以在42～84d之间调控,药物缓释达到了理想的零级动力学释放.因此,利福平PLGA微球具有显著的长效、恒量药物缓释作用.

Preparation and in Vitro Release of Rifampin Microspheres Encapsulated in Biodegradable Polyesters

Microspheres containing antiphthisic drug Rifampin were prepared from poly(lactide-co-glycolide) (PLGA) as carrier by emulsion and solvent evaporation method. The conditions of the microsphere preparation such as the drug/carrier molar ratio, the volume ratio of organic solvent to water, PLGA concentration in organic solvent, speed of emulsification, kind of stabilizer, relative molecular weight of {PLGA}, LLA/GA mass ratio were discussed. The surface morphology of the microspheres in original and degraded states was observed by SEM. The mean diameter and drug content of microspheres were examined, and the drug release %in vitro% was evaluated. The morphology of the microspheres prepared from {PLGA} and by 1% gelatin as the stabilizer was integral with 10—30 μm diameter range, 24.3% average drug content, 42—84 d drug-release time. The drug-release kinetics with zero order satisfies the requirements of controlled drug-release.