Objective: To investigate the pharmacokinetics of berberine in Coptidis Rhizoma extract in rat intestinal and bile. Method: A simple and accurate high-performance liquid chromatography method was used to determine the concentration of berberine in the rat intestinal and bile samples. Result: Following the intravenous administration of Coptidis Rhizoma extract

B/P (concentration in the bile/concentration in the plasma) of berberine was determined to be 69.1~497.9 from 0.25 h to 4 h. Bile excretion was one of the main excretion ways for rats to eliminate berberine of Coptidis Rhizoma alkaloids. Most of berberine in the intestinal was from the bile. While bile was discharged from rats

berberine still could be determined in the intestinal. Conclusion: The results proved that berberine could be transported from blood to intestinal in the animal model with a direction from basolateral membrane to apical membrane. P-glycoprotein is involved in the transport mechanism.