目的 考察葛根素羧甲基壳聚糖微球的在体肠吸收特性。方法 采用大鼠在体单向灌流法，以HPLC法测定葛根素的量，分别考察不同灌流体积流量、药物质量浓度、肠段对药物吸收的影响，并对比了葛根素原料药及载药微球的吸收特性。结果 灌流体积流量对葛根素的吸收速率常数（K_a）和表观渗透系数（P_app）有显著性影响（P < 0.05）；葛根素的质量浓度对K_a和P_app无显著性影响（P > 0.05）；葛根素在空肠和回肠的K_a和P_app无显著性差异，但均显著大于在十二指肠处的值（P < 0.05）；载药微球在空肠的K_a和P_app值显著高于葛根素原料药（P < 0.05）。结论 葛根素羧甲基微球中葛根素的吸收机制为被动扩散，其在空肠和回肠段吸收较好，羧甲基壳聚糖作为载体能显著提高葛根素的吸收。

Objective To study the rat intestinal absorption characteristic of puerarin loaded O-carboxymethyl chitosan (CMCS) microspheres in situ. Methods Single-pass intestinal perfusion (SPIP) model was used for rat in situ and HPLC to determine the concentration of puerarin. The effects of different perfusion rate, drug concentration, and intestinal segments on intestinal absorption were investigated, and the absorption characteristics of the puerarin and puerarin loaded O-CMCS microspheres were compared. Results Perfusion rate had significant effect on the absorption rate constants (K_a) and the apparent absorption coefficient (P_app) (P < 0.05); The concentration of puerarin in perfusate had no significant effect on K_a and P_app (P > 0.05); K_a and P_app of drug loaded microspheres in jejunum and ileum showed no significant difference, but they were significantly higher than that in duodenum (P < 0.05); The drug loaded microspheres and puerarin had the significant difference in K_a and P_app in jejunum (P < 0.05). Conclusion The absorption mechanism of puerarin in the microspheres is passive diffusion, puerarin is absorbed well in jejunum and ileum, and puerarin loaded O-CMCS microspheres can significantly improve the absorption of puerarin.

国家自然科学基金资助项目（81373944）；陕西省科技统筹创新工程计划项目（2012KTCQ03-13）