普拉克索的大鼠在体肠吸收

In situ Absorption Kinetics of Pramipexole in Rats Intestine

采用大鼠在体灌流法,以灌流液中剩余药物浓度为指标,考察普拉克索(1)在不同吸收部位的吸收动力学特征以及不同pH、不同药物浓度对1全肠段吸收的影响。结果显示,1在不同肠段的吸收速率常数(h-1)分别为:十二指肠0.295、结肠0.513、回肠0.480 h和空肠0.808 h。药物在大鼠全肠道内的吸收量随药物浓度的增大而升高,药物浓度和pH对吸收速率常数无显著性影响。1在肠道的吸收符合一级动力学特征,吸收机制为被动吸收。采用大鼠在体胃灌注法,以胃灌注液中药物前后浓度变化计算1在胃部吸收情况。结果表明1几乎不吸收。

The absorption kinetics of pramipexole(1) at different intestinal segments in rats and the influence of concentration and pH on the absorption kinetics were investigated with in situ perfusion.An HPLC method was developed to determine the concentrations of 1 in intestinal circulated fluid.The results showed that 1 can be absorbed in whole intestine.The absorption rate constants(Ka) at duodenum,colon,ileum and jejunum were 0.295 h-1,0.513 h-1,0.480 h-1 and 0.808 h-1,respectively.The absorptions in intestine were increased by the drug concentrations.The concentration of 1 and pH had no distinctive effect on the absorption kinetic.The absorption of 1 was in line with first-order kinetics with passive diffusion absorption mechanism.The absorption kinetics of stomach was obtained by the in situ perfusion method in rats.There is little absorption of 1 in stomach.