玻璃体内注射用地塞米松微球的制备

Preparation of dexamethasone microspheres for intravitreally injection

目的为治疗增殖性玻璃体视网膜病变,制备玻璃体内注射用地塞米松微球。方法以生物可降解乙交酯和丙交酯的无规共聚物(PLGA)为载体材料,采用W/O型乳化-溶剂挥发方法制备地塞米松微微球。研究影响微球制备的工艺条件,考察了微球的粒径大小与分布、载药量和包封率,评价载药微球的体外释放行为。结果微球形态完整,表面光滑,微球的粒径范围为4.70±1.6μm,载药量为(15.5±0.32)%,包封率为(78.8±1.3)%。体外释药13d约90%,属扩散-溶蚀机制。结论制备方法可行,地塞米松PLGA微球具有药物缓释作用。可以作为玻璃体内注射用地塞米松的给药载体。

OBJECTIVE The purpose of this research was to develop polylactic-co-glycolic acid（PLGA） microspheres for continuous delivery of dexamethasone which is used to suppress the proliferative vitreoretinopathy. METHOD The micropheres were prepared by an oil-in-water emulsion-solvent evaporation technique. Properties such as geometric mean diameter, drug loading, rate of entrapment and release characteristics were evaluated. RESULTS The average diameter was 4.70 ± 1.6μm. The encapsulation efficiency was （78.8 ± 1.3 ） % , and the drug loading was （ 15.5 ± 0.32 ） %. Ninety percent of the dexamethasone was released in vitro from the microspheres after 13 days. The release mechanism was controlled with drug diffusion and polymeric erosion. CONCLUSION The technology of preparation is successful and the microspheres can provide continuous release of dexamethasone.