白藜芦醇纳米脂质体体外释药和大鼠小肠吸收特性的研究

目的：考察白藜芦醇纳米脂质体的体外释药性质,研究小肠最佳吸收部位及其吸收机制。方法：以动态透析法测定白藜芦醇纳米脂质体体外释药速率；以大鼠在体肠循环法研究白藜芦醇纳米脂质体在大鼠十二指肠、空肠、回肠及结肠中的吸收动力学特征及考察不同质量浓度(20,40,60,80 μg·mL^-1)的白藜芦醇纳米脂质体在大鼠肠道的吸收行为。结果：药物的体外释放以对数正态分布方程拟合最好；白藜芦醇纳米脂质体在回肠段的吸收速率常数高于其他肠段,差异具有显著性(P<0.001)。不同质量浓度的白藜芦醇纳米脂质体在小肠的吸收速率常数(ka)不具有显著性差异。结论：白藜芦醇纳米脂质体在体外释放介质中可缓慢持续释药；在小肠回肠部位吸收较好,药物质量浓度对ka无影响,吸收呈一级动力学过程,吸收机制为被动扩散。纳米脂质体作为载体可以促进白藜芦醇在小肠的吸收。

Study on drug release in vitro and rat intestinal absorption of resveratrol Nanoliposomes

Objective: To study the release feature of Res-nanoliposomes in vitro and clarify the difference in absorption of Res-nanoliposomes from varied intestinal segments and the absorptive mechanism in vivo. Method: Dialytic method was used to determine resveratrol release rate of Res-nanoliposomes in vitro. An in situ rat perfusion method was used to investigate the intestinal absorption of Res-nanoliposomes. Result: Resveratrol release from nanoliposomes in vitro fitted the log-normal distribution equation and had a property of sustained release. Compared with other intestinal segments, significantly high percentage of Res-nanoliposomes was absorbed in ileum (P<0.001). The absorption rate constants (ka) of Res-nanoliposomes in intestine were not significantly different. Conclusion: Res-nanoliposomes could sustain to release drug in vitro. The absorption was a first-order process with the passive diffusion mechanism. The Res-nanoliposomes could promote the absorption of Res in rat small intestine.