Jalil R, Nixon J R
Chelsea Department of Pharmacy, King's College London, University of London.
J Microencapsul. 1990 Jul-Sep;7(3):375-83. doi: 10.3109/02652049009021847.
Poly (DL-lactic acid) [DL-PLA] microcapsules containing phenobarbitone were prepared using a W/O emulsion method. Microcapsules of nominal C : P ratio, 1 : 2 and 1 : 3 using three different molecular weight polymers, 20,500, 13,300 and 5,200 were investigated to study the effect of storage conditions on the microcapsule properties. All microcapsules were stored under desiccated condition at temperatures of 4 degrees, 20 degrees and 37 degrees C for six months. Storage temperatures of 4 degrees and 20 degrees C did not cause appreciable changes in the release rate after storage. Microcapsules stored at 37 degrees C showed an annealing effect, causing shrinkage of microcapsules, and lowering of the release rate after storage for six months. The microcapsules prepared from low molecular weight DL-PLA fused completely whilst stored at 37 degrees C and the other two high molecular DL-PLA also showed some aggregation. There were insignificant variations in the mean microcapsule diameter during storage. The phenobarbitone content of the microcapsules was also unchanged.
采用水包油乳液法制备了含有苯巴比妥的聚（DL-乳酸）[DL-PLA]微胶囊。使用三种不同分子量的聚合物（20500、13300和5200），研究了标称C:P比为1:2和1:3的微胶囊，以考察储存条件对微胶囊性能的影响。所有微胶囊在4℃、20℃和37℃的干燥条件下储存6个月。4℃和20℃的储存温度在储存后未引起释放速率的明显变化。在37℃储存的微胶囊表现出退火效应，导致微胶囊收缩，并在储存6个月后释放速率降低。由低分子量DL-PLA制备的微胶囊在37℃储存时完全融合，另外两种高分子量DL-PLA也出现了一些聚集现象。储存期间微胶囊的平均直径变化不显著。微胶囊中苯巴比妥的含量也未发生变化。
