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 Objective To investigate the absorption kinetics, absorption sites and absorption mechanism of naproxen sodium in various segments of the intestine, in order to provide an important basis for the design of long-acting sustained release formulations of drugs. Methods Rat intestinal absorption test in vivo intestinal absorption of naproxen sodium and absorption kinetics characteristics. Results Naproxen sodium absorbed well in the small intestine, the absorption rate decreased in the order of jejunum, ileum, duodenum and colon, the absorption rate constants were 0 .5 96,0 .5 3 6,0 .3 78, 0 .14 6h- 1. Drug absorption in the intestine presents first-order absorption kinetics and the absorption mechanism is passive absorption. The absorption window of the drug is above the colon. Conclusion Naproxen sodium absorption window is relatively long, suitable for the preparation of a sustained-release drug delivery system. The colon absorption rate constant is about the small intestine segment of 3 10, which in turn suggests that naproxen sodium once daily sustained-release formulations, it is best to extend the formulation of the gastrointestinal tract in the middle of the retention time