Abstract: AIM: To study the rat intestinal absorption of henatinib maleate in situ.METHODS: The rat single-pass intestinal perfusion technique was applied, and the gravimetry was used to correct the perfusion volume.The concentration of henatinib was determined by HPLC.A series of studies were carried out including the absorption under different bile secretion conditions, at different concentrations and at different intestinal regions.RESULTS: The drug absorption rate constants (K_a) were 3.5×10^-2, 4.3×10^-2/min, respectively, and the apparent absorption coefficients (Papp) were 3.0×10^-3, 3.1×10^-3 cm/min, respectively, in the groups of bile duct ligation and without bile duct ligation.Moreover, Ka were 3.9×10^-2, 4.3×10^-2, 4.3×10^-2/min, respectively, and Papp were 2.3×10^-3, 3.1×10^-3, 3.1×10^-3 cm/min, respectively, at three perfusate drug concentrations of high, middle and low levels.And Ka were 4.5×10^-2, 3.7×10^-2, 4.2×10^-2, 4.1×10^-2/min, respectively, and Papp were 3.3×10^-3, 2.8×10^-3, 3.0×10^-3, 3.5×10^-3cm/min, respectively, on the duodenum, jejunum, ileum and colon.CONCLUSION: The absorption of henatinib is not apparently influenced by bile secretion.Concentration of henatinib has no significant effect on its absorption in all segments of rat intestine.The absorption is consistent with passive transportation.Henatinib is well absorbed in every segment of the intestine and has no specific absorption site.So, henatinib can be made into oral dosage forms.

Key words: single-pass intestinal perfusion, intestinal absorption, gravimetry, HPLC, henatinib maleate