布洛芬平衡溶解度及表观油水分配系数的测定

目的：测定布洛芬在不同pH磷酸盐缓冲溶液中的平衡溶解度与表观油水分配系数。方法采用紫外－可见分光光度法测定布洛芬的质量浓度，气浴恒温振荡－摇瓶法测定布洛芬的平衡溶解度及表观油水分配系数。结果37℃时布洛芬在pH2．0、3．0、4．0、5．0、6．0、6．8、7．4、8．0、9．0缓冲溶液中的平衡溶解度分别为0．05874、0．04078、0．06404、0．1930、1．027、2．551、4．613、3．866、4．409mg? mL －1；表观油水分配系数分别为10．19、17．11、12．55、6．390、4．911、5．976、4．925、2．599、1．716。结论布洛芬在磷酸盐缓冲溶液中的平衡溶解度及表观油水分配系数与介质的pH值相关，介质的pH值的增大，布洛芬的平衡溶解度增大；表观油水分配系数减小。

Determination of EquiIibrium SoIubiIity and Apparent OiI/Water Partition Coefficient of Ibuprofen

OBJECTIVE To determine the equilibrium solubility and apparent oil-water partition coefficient of ibuprofen in different pH phosphate buffer solutions.METHODS Concentrations of ibuprofen were determined by ultraviolet spectrophotometry ( UV) method;A shake-flasking method was applied to determine the equilibrium solu-tion and partition coefficient of ibuprofen.RESULTS The equilibrium solubility of ibuprofen in different pH phos-phate buffered solution of pH 2.0,3.0,4.0,5.0,6.0,6.8,7.4,8.0 and 9.0 were 0.05874,0.04078,0.06404, 0.1930,1.027,2.551,4.613,3.866 and 4.409mg? mL-1;And the apparent oil-water partition coefficient were 10.19,17.11,12.55,6.390,4.911,5.976,4.925,2.599 and 1.716 at 37℃.CONCLUSION The equilibrium solubility and apparent oil/water partition coefficient were correlated to the pH of medium.With the increase of pH value,the equilibrium solubility rised,while the apparent oil/water partition coefficient decrease.