Studies on absorptive mechanism of lipophilic components of danshen from its hydroxypropyl-beta-cyclodextrin inclusion complex / 生物医学工程学杂志

ABSTRACT

Taking Tanshinon IIA as the target and using reversed phase high performance liquid chromatography,we have developed a rapid and sensitive assay for lipophilic components of Danshen (LCD) in perfusate. The model of intestinal absorption was used to determine the concentration of Tanshinon IIA in rats as an in situ model. The change of concentration of Tanshinon IIA was separately calculated according to Michaelis-Menten and the Fick's equation to investigate the absorptive limit step of the LCD. It was concluded that the limit step to absorption of LCD was at the dissolution, by assessing the fitting index or correlative index. On the basis of the conclusion, the experiment was designed to prepare the inclusive complex of the LCD with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and to study its absorptive mechanism. With the increase of dosage of complex, its absorption did not show saturated phenomenon in gastro-intestinal tract in rats and the constant Ka did not show significant difference, suggesting that the transport of mechanism in vivo is similar to passive transport.