水飞蓟素微乳大鼠在体小肠吸收的动力学

The absorption kinetics of silymarin microemulsion in rat intestine

目的 考察水飞蓟素微乳的形态学和粒径分布 ,研究水飞蓟素微乳在小肠各部位的吸收情况 ,并与水飞蓟素胶束在空肠的吸收进行比较。方法 采用大鼠在体小肠段回流实验 ,紫外分光光度法测定药物浓度 ,依据药物在小肠段中的减少量来确定药物的吸收。结果 透射电镜下水飞蓟素微乳成球形或近球形 ,大小均匀 ,平均粒径约为 2 0nm。在整个小肠、回肠、空肠、十二指肠以及结肠中的吸收速率常数依次是 6 2 2× 10 - 2 ,2 2 7× 10 - 2 ,1 9× 10 - 2 ,1 0 5× 10 - 2 ,0 4 3× 10 - 2 h- 1 ,两种水飞蓟素胶束在空肠的吸收速率常数分别是 0 36× 10 - 2 ,0 6 5× 10 - 2 h- 1 。结论 水飞蓟素微乳在小肠下段吸收较好 ,吸收呈一级动力学过程 。

Aim To survey the morphology and size distribution of silymarin microemulsion, to investigate the absorption of silymarin microemulsion in rat intestine compared with the absorption of silymarin micelle in rat Jejunum. Methods The intestine in rats was canulated for in situ recirculation. Results The absorption rate constants (K a) of silymarin microemulsion at the entire intestine, ileum , jejunum, duodenum and colon were 6.22×10 -2, 2.27×10 -2, 1.9×10 -2, 1.05×10 -2 and 0.43×10 -2 h -1 , respectively. The absorption rate constants of two kinds of silymarin micelle at jejunum were 0.36×10 -2, 0.65×10 -2 h -1 . Conclusion Silymarin microemulsion was well absorbed at the middle and lower segments of intestine in rats. The absorption was a first-order process with the passive diffusion mechanism.