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目的制备生物可降解型NC-PLGA缓释微球,研究其制备工艺与体内、体外释放特性。方法利用溶剂挥发法制成NC-PLGA缓释微球,在人工脑脊液中用紫外分光光度法测定其体外释放速度,在兔脑脊液中用HPLC法测定其体内释放速度。结果 NC-PLGA外观形态为直径(31.3±3.2)μm的微球,载药率为13.7%,包封率为89.2%。微球体外试验显示,前两天有初始突释现象,共释放约30%,药物能够在随后时间内缓慢平稳释放至20d以上。兔体内试验结果表明,除了第一天的初始突释外,微球释药缓慢而平稳,每天的血药浓度维持在7.6×10-8 mol/L。结论利用溶剂挥发法制得NC-PLGA缓释微球,具有明显的缓释作用。
Objective To prepare biodegradable NC-PLGA sustained release microspheres and study its preparation process and in vitro and in vivo release characteristics. Methods NC-PLGA sustained-release microspheres were prepared by solvent evaporation method. The release rate in vitro was measured by ultraviolet spectrophotometry in human cerebrospinal fluid and the release rate in vivo by HPLC method in rabbit cerebrospinal fluid. Results The morphology of NC-PLGA was microspheres with a diameter of (31.3 ± 3.2) μm. Drug loading rate was 13.7% and encapsulation efficiency was 89.2%. Microspheres in vitro tests showed that the first two days before the initial burst phenomenon, a total release of about 30%, the drug can be slowly and steadily released in the subsequent time to 20d or more. The results of in vivo experiments in rabbits showed that in addition to the initial burst on the first day, the release of microspheres was slow and steady. The daily plasma concentration was maintained at 7.6 × 10-8 mol / L. Conclusion The NC-PLGA sustained-release microspheres prepared by solvent evaporation have obvious sustained release effect.