Adeyeye C M, Price J C
Department of Pharmaceutical Chemistry and Pharmaceutics, School of Pharmacy, Duquesne University, Pittsburgh, Pennsylvania 15282.
Pharm Res. 1991 Nov;8(11):1377-83. doi: 10.1023/a:1015845022112.
A congealable disperse phase encapsulation method was used to prepare sustained-release ibuprofen-wax microspheres. Microspheres prepared with paraffin wax, such as ceresine and microcrystalline waxes, using polyvinylpyrrolidone (PVP) as dispersant had a tendency to aggregate, but the addition of wax modifiers (stearyl alcohol and glyceryl monostearate) greatly reduced aggregation. Optimum modifier and dispersant concentrations were 20% (w/w) and 5% (w/v), respectively. The particle size distribution of the microspheres was log-normal. An increase in modifier, dispersant concentration, emulsification stirring speed, or temperature shifted the size distribution toward finer particles. Microcrystalline wax required a higher emulsification temperature and produced finer particles than ozokerite wax. The recovery of drug from the different microsphere formulations varied between 71 and 92%. Differential scanning calorimetry (DSC) of the single components and physical mixtures showed endothermic peaks at the respective melting-point ranges. The DSC of the ceresine and microcrystalline wax microspheres was similar to rescans of ternary mixtures of components of the microspheres with less prominent and lower melting temperatures than individual components or physical mixtures.
采用可凝结分散相包封法制备了布洛芬-蜡缓释微球。以聚乙烯吡咯烷酮（PVP）为分散剂，用石蜡（如微晶蜡和地蜡）制备的微球有聚集的倾向，但添加蜡改性剂（硬脂醇和单硬脂酸甘油酯）可大大减少聚集。改性剂和分散剂的最佳浓度分别为20%（w/w）和5%（w/v）。微球的粒度分布呈对数正态分布。改性剂、分散剂浓度、乳化搅拌速度或温度的增加会使粒度分布向更细的颗粒方向移动。微晶蜡比地蜡需要更高的乳化温度，且产生的颗粒更细。不同微球制剂的药物回收率在71%至92%之间。单一组分和物理混合物的差示扫描量热法（DSC）在各自的熔点范围内显示出吸热峰。微晶蜡和地蜡微球的DSC与微球组分三元混合物的重新扫描结果相似，其熔点温度比单个组分或物理混合物更不明显且更低。
