乳化-溶剂挥发法制备乙基纤维素/萘普生复合微球

以乙基纤维素（EC）为载体材料，萘普生为包埋药物，采用O/W型乳化-溶剂挥发法制备了包封率较高的EC/萘普生复合载药微球，利用正交试验优化制备工艺，得出当EC与萘普生的质量比为3：1，EC用量2.5%，聚乙烯醇用量0.8%，吐温-80用量0.4%时是复合微球的最佳制备工艺，在该工艺条件下药物包封率达到88.97%。通过扫描电子显微镜（SEM）、激光粒度分析、傅里叶变换红外光谱（FT-IR）对复合微球的形态和结构进行了分析表征。SEM显示复合微球的形态顺滑，激光粒度分析表明复合微球平均粒径为14.014μm，复合微球的FT-IR谱图中既有EC的特征峰，又有萘普生的特征峰，但没有新基团产生，表明EC包覆萘普生过程中未产生新化合物。体外释放实验表明复合微球的累积释药率随溶出介质pH值的增大而增大，在溶出介质pH值为9时，复合微球的累积释药率最大，达到82.5%，缓释性能较好。

Preparation of Ethyl Cellulose/Naproxen Composite Microspheres Through Emulsion-solvent Evaporation Method

Ethyl cellulose/naproxen composite microspheres with high encapsulation efficiency were prepared by O/W emulsion-solvent evaporation method with ethyl cellulose as the carrier material and naproxen as the entrapped object. Orthogonal experiment was used to optimize the preparation process. And the results indicated that the optimal conditions were the mass ratio of ethyl cellulose and naproxen 3:1, ethyl cellulose addition 2.5%, polyvinyl alcohol addition 0.8%, Tween-80 addition 0.4%. Under these conditions, the encapsulation efficiency of naproxen was 88.97%. The morphology and structure of composite microspheres were investigated by scanning electron microscope(SEM), laser granularity analyzer and Fourier transform infrared spectroscopy(FT-IR). The SEM observation showed that composite microspheres were smooth, and laser granularity analyzer demonstrated that the mean diameter of particles was 14.014μm. The FT-IR showed that the characteristic adsorption peaks of EC and naproxen all appeared in the spectrum of microsphere and there was no new peak. This indicated no new compound generated during EC coating naproxen. The experiment of drug releasing indicated that the accumulative release rate increased with the increase of pH value of dissolution medium and reached the maximum of 82.5% at pH 9. And the composite microspheres showed better sustained release of drug.