磺胺二甲嘧啶的溶解度及油水分配系数的研究

目的:研究磺胺二甲嘧啶(SM2)在不同pH值下的平衡溶解度和油水分配系数(Ko/w),为SM2制剂的开发提供基础研究。方法:配制不同pH值的磷酸盐缓冲液,采用饱和法测定其表观溶解度;通过SM2分配平衡后在油相(正辛醇)和水相的浓度比,计算油水分配系数。结果:SM2在pH2·0和pH9·0时平衡溶解度较高,分别为1·916、1·375g·L-1,油水分配系数在pH8·0时最高,为3·9070。结论:SM2在水中的平衡溶解度及油水分配系数与介质的pH值有关,pH<3·0或pH>6·8时溶解度较好。pH3～8时SM2在油相中分配较多,较易被机体吸收。

Solubility and Apparent Oil/Water Partition Coefficient of Sulfamethazine

OBJECTIVE： To determine the equilibrium solubility and the apparent partition coefficient of sulfamethazine （SMz） in a series of phosphate buffer solutions of different pH so as to provide a basic study for the exploitation of SM2 preparation. METHODS： A series of buffer solutions of different pH were prepared. The apparent solubility was determined by saturation method; Ko/w was calculated with concentration ratio of SM2 in n - octanol and water phase after partition equi- librium, RESULTS： The maximum equilibrium solubility was 1.916 g· L^-1 at pH 2 and 1.375 g·L^-1 at pH 9, and the maximum of apparent partition coefficient was 3.9070 at pH 8. CONCLUSION： The equilibrium solubility and apparent partition coefficient of SM2 are correlated to pH of the medium. SM2 dissolved preferably when pH〈3 or pH〉6.8, but SM2 was more distributed in the lipid phase and easier to be absorbed by body when pH = 3-8.