姜黄素和胡椒碱溶解度和表观油水分配系数的测定

Determination of the Solubility and Apparent Oil-water Partition Coefficient of Curcumin and Piperine

目的：测定姜黄素和胡椒碱的溶解度及表观油水分配系数，研究pH值对其的影响，为姜黄素和胡椒碱的剂型设计提供参考。方法：采用HPLC法在同一条件下测定姜黄素和胡椒碱的含量，并测定姜黄素和胡椒碱在不同有机溶剂中的溶解性，采用摇瓶法测定姜黄素和胡椒碱在不同pH条件下的表观溶解度，并对其在正辛醇-水缓冲溶液中的表观油水分配系数进行测定。结果：姜黄素在无水乙醇、丙二醇、丙三醇、PEG400和正辛醇中的溶解度分别为0.0214g·ml-1、0.0201g·ml-1、0.0100g· ml-1、0.0636g·ml-1和0.0328g·ml-1，胡椒碱在无水乙醇、丙二醇、丙三醇、PEG400和正辛醇中的溶解度分别为0.0478g·ml-1、0.0220g·ml-1、0.0128g·ml-1、0.0619g·ml-1和0.0443g·ml-1；25℃下姜黄素和胡椒碱的表观正辛醇/水分配系数P分别为4738.609（Log P=3.6757）和72.9199（Log P=1.8628）。结论：姜黄素在不同的pH缓冲溶液中不溶，而胡椒碱在不同的缓冲溶液中均具有一定的溶解性，随着pH的升高溶解度逐步增加；姜黄素和胡椒碱均为脂溶性成分，较难溶于水。

Objective:To determine the solubility, apparent oil-water partition coefficient and the pH value of its implications of curcumin and piper-ine, which can provide reference for novel exploitation. Methods:The concentrations of curcumin and piperine and the solubility of them in different organic solvents were determined by HPLC at the same conditions. The determination of curcumin and piperine at different pH conditions apparent solubility, and its apparent oil-water partition coefficient was measured by shake flask. Results:Solubility of Curcumin in ethanol, propylene glycol , glycerol , PEG400 and n-octanol were 0.021 4 g·ml-1, 0.020 1 g·ml-1, 0.010 0 g·ml-1, 0.063 6 g·ml-1 and 0.032 8 g·ml-1, furthermore, the solubil-ity of piperine in ethanol, propylene glycol , glycerol , PEG400 solubility and octanol were 0.0478 g·ml-1, 0.022 0 g·ml-1, 0.012 8 g·ml-1, 0.061 9 g·ml-1 and 0.044 3 g·ml-1. The apparent oil-water partition coefficient of curcumin and piperine were 4738.609 (Log P=3.675 7) and 72.919 9 (Log P=1.862 8 ) at 25℃, respectively. Conclusions:Curcumin was insoluble in buffer solution at different pH;while piperine having a solubility in a different buffer solution, with gradual increase of pH increases the solubility . Curcumin and piperine are fat-soluble ingredients, difficult to dis-solve in water.