Realdon N, Ragazzi E, Dal Zotto M, Dalla Fini G
Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Padua, Italy.
Drug Dev Ind Pharm. 1998 Apr;24(4):337-43. doi: 10.3109/03639049809085628.
A drug with cationic characteristics such as procaine can be conveyed in a Carbomer hydrogel in two different ways: (i) in the form of salt in solution in the aqueous phase, and (ii) in the base form salified with the same polymer. Introduction of the drug into the hydrogel with different concentrations of polymer produced, in both cases, a reduction in viscosity in relation to drug concentration. The gels with procaine salified with the polymer showed greater viscosity. The drug release rate, in general, diminished with the increase in polymer concentration. Nevertheless, when this concentration was maintained, there was no variation in release rate when the viscosity produced as a consequence of drug concentration was changed. Gels with procaine salified with the carboxyvinylic polymer had a faster release rate than those with procaine in the hydrochloride form dissolved in the aqueous phase. These results have also been confirmed by a simulated absorption test.
具有阳离子特性的药物（如普鲁卡因）可以通过两种不同方式负载于卡波姆水凝胶中：（i）以盐的形式溶解于水相溶液中，以及（ii）以与相同聚合物成盐的碱形式存在。在两种情况下，将不同聚合物浓度的药物引入水凝胶中均会导致相对于药物浓度而言粘度降低。聚合物成盐的普鲁卡因凝胶表现出更高的粘度。一般来说，药物释放速率会随着聚合物浓度的增加而降低。然而，当保持该浓度时，因药物浓度产生的粘度变化时，释放速率并无变化。羧乙烯基聚合物成盐的普鲁卡因凝胶比盐酸盐形式溶解于水相中的普鲁卡因凝胶具有更快的释放速率。这些结果也已通过模拟吸收试验得到证实。
