HPLC法测定维A酸的平衡溶解度及表观油水分配系数

目的建立HPLC法,模拟人体皮肤环境,测定维A酸在水、正辛醇中的平衡溶解度,以及在正辛醇-缓冲液体系中的表观油水分配系数。方法采用HPLC法测定维A酸的浓度,采用摇瓶法测定维A酸的表观油水分配系数。结果在32℃下,pH为5.8时,测得维A酸在正辛醇中的溶解度为6.25 mg/mL,在水中的溶解度小于0.1 mg/mL,维A酸的表观油水分配系数为36 079.8（lgP=4.55）。结论本文建立的HPLC法,可用于维A酸溶解度及油水分配系数的测定,该方法简便、准确。

Determination of equilibrium solubility and apparent oil/water partition coefficient of tretinoin by HPLC

Objective To determine the equilibrium solubility of tretinoin in water and n-octyl alcohol,as well as to determine its apparent oil/water partition coefficient in the n-octane-water/buffer solution for establishing a high performance liquid chromatographic method by simulating the environment of human skin.Methods The concentration of tretinoin was determined by HPLC,apparent oil/water partition coefficient was measured by shaking flask method.Results The equilibrium solubility of tretinoin in n-octyl alcohol was 6.25 mg/mL and the equilibrium solubility of that in water was below 0.1 mg/mL,at 32℃,pH 5.8,and the apparent oil/water partition coefficient was 36 079.8（lgP=4.55）.Conclusion The method is accurate and reliable,which can be used in the determination the equilibrium solubility of tretinoin as well as its apparent oil/water partition coefficient.