丹皮酚平衡溶解度与油水分配系数测定及大鼠在体肠吸收研究

目的 测定丹皮酚在各种溶剂中的平衡溶解度及表观油水分配系数,并研究其在体肠吸收性质.方法 HPLC法测定丹皮酚的浓度,用摇瓶法测定丹皮酚的表观油水分配系数,大鼠在体单向肠灌流实验,按重量法计算动力学参数.结果 25℃丹皮酚在水中的平衡溶解度为0.5 g/L,在酸性磷酸盐缓冲液中的平衡溶解度较低,碱性磷酸盐缓冲液中的平衡溶解度较高,在常用的有机溶剂中的溶解度大于1 g/L;25℃丹皮酚在正辛醇-水系统中的油水分配系数Papp为263.2( lgPapp=2.42)；丹皮酚在肠道各部位的吸收速率按空肠、回肠、十二指肠、结肠顺序下降.结论 不同pH值的介质对丹皮酚表观油水分配系数影响不大；丹皮酚在整个肠段均有吸收,小肠为主要吸收部位.

Equilibrium solubility and oil-water partition coefficient of paeonol and its intestinal absorption in rats

AIM To determine the equilibrium solubility and the apparent oil-water partition coefficient of paeonol and to investigate its absorption mechanism in rat intestines.METHODS The concentration of paeonol was determined by HPLC.A shake flask method was established to determine the equilibrium solubility and the oil-water partition coefficient of paeonol.In situ rat intestinal perfusion model was employed to calculate the kinetic parameters by weight methods.RESULTS The equilibrium solubility of paeonol in water reached 0.5 g/L at 25 ℃ and higher in alkaline phosphate buffer than that in acidic.The equilibrium solubility in common organic solvents was greater than 1 g/L.The log Papp of paeonol in octanol-water system was 2.42.Paeonol was well absorbed in intestinal tract,where its absorption rate constant(Ka) was in turn duodenum > jejunum > ileum > colon.Ka and Papp in rat colon were relatively lower than those in other intestinal tracts.CONCLUSION The pH of buffer solution has little influence on its distribution coefficient of paeonol,and is well absorbed in general intestinal tract with small intestine.