Khidr S H, Niazy E M, el-Sayed Y M
Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
J Microencapsul. 1995 Nov-Dec;12(6):651-60. doi: 10.3109/02652049509006795.
Sustained-release metoclopramide microspheres were successfully prepared using cellulose propionate polymer at 1:2 drug to polymer ratio employing solvent evaporation technique and using acetone as the polymer solvent. The prepared microspheres at three stirring speeds were characterized with regard to their drug content, particle size distribution, surface topography using SEM and their release profiles at two different pHs at 37 degrees C. The surface of all samples was smooth with very few irregular elevations or depressions. The average particle size decreases as the rotational speed increases and was found to be 1320, 774 and 345 microns at 600, 900 and 1200 rpm, respectively. The average % drug entrapped was found to be 90.5, 100.1 and 60.0% at 600, 900 and 1200 rpm, respectively. Small differences in the release rate were observed due to different rotation speeds with an apparent lower dissolution for batches produced at 1200 rpm probably due to the properties of the coat. The effect of storage under accelerated conditions for 10 weeks on the release characteristics of these microspheres was also studied. The release properties of the microspheres did not change after storing them at 40 degrees C/80% relative humidity for 10 weeks.
采用溶剂蒸发技术，以丙酸纤维素聚合物为载体，按药物与聚合物1:2的比例，用丙酮作为聚合物溶剂，成功制备了甲氧氯普胺缓释微球。对三种搅拌速度下制备的微球进行了表征，包括药物含量、粒径分布、用扫描电子显微镜观察表面形貌以及在37℃下两种不同pH值时的释放曲线。所有样品的表面都很光滑，只有很少的不规则凸起或凹陷。平均粒径随转速增加而减小，在600、900和1200转/分钟时分别为1320、774和345微米。在600、900和1200转/分钟时，平均包封药物百分比分别为90.5%、100.1%和60.0%。由于转速不同，释放速率存在微小差异，1200转/分钟制备的批次明显溶解较慢，这可能是由于包衣的性质所致。还研究了在加速条件下储存10周对这些微球释放特性的影响。在40℃/80%相对湿度下储存10周后，微球的释放特性没有改变。
