萘普生钠在大鼠的肠吸收动力学

目的　探明萘普生钠在肠道各区段的吸收动力学特征、吸收部位及吸收机制 ,以期对药物的长效缓释制剂的设计提供重要的依据。方法　采用大鼠在体肠灌流吸收实验 ,研究了萘普生钠的吸收部位和吸收动力学特征。结果　萘普生钠在小肠部位吸收良好 ,吸收速度按空肠、回肠、十二指肠、结肠的顺序依次下降 ,吸收速度常数依次为 0 .5 96、0 .5 3 6、0 .3 78、0 .14 6h- 1 。药物在肠道的吸收呈现一级吸收动力学特征且吸收机制为被动吸收。药物的吸收窗为结肠以上部位。结论　萘普生钠的吸收窗比较长 ,适于制备日服一次的缓释给药系统。而结肠的吸收速度常数大约是小肠段的 3 10 ,这又提示设计萘普生钠日服一次的缓释制剂时 ,最好能延长制剂在胃肠道上中部的滞留时间

Absorption Kinetics of Naproxen Sodium in Rats

Purpose To ascertain the absorption properties of naproxen sodinm from various intestinal segments in order to devise the sustained release dosage forms of nap Na. Methods The absorption kinetics and absorption site were investigatd using in situ perfusion method in rats. Results It was showed that the small intestine was the best absorption segment.The absorption rate decreased according to the turn of jejunum,ileum,duodenum and colon.The absorption rate constants were 0.596 , 0.536 ,0.378,0.146 h -1 at duodenum,jejunum,ileum and colon respectively. Conclusions The absorption of nap?Na complies with the passive transport mechanism and first order kinetics.Nap?Na can be prepared and processed into sustained release dosage forms for once a day.