RESUMEN
<p><b>OBJECTIVE</b>To study the transportation of Xiaochaihu Tang in Caco-2 cell model.</p><p><b>METHOD</b>The safety concentration of Xiaochaihu Tang in Caco-2 cells was determined by MTT assay. Then the Caco-2 cell model was used to investigate the bi-directional transportation of Xiaochaihu Tang. The multicomponents of Xiaochaihu Tang and the influence of time were measured by high performance liquid chromatography (HPLC).</p><p><b>RESULT</b>The P(app) values of wogonoside and wogonin were (1.23 +/- 0.09) x 10(-6), (1.07 +/- 0.89) x 10(-5) cm x s(-1) from the AP side to BL side, and (2.12 +/- 0.19) x 10(-6) and (7.12 +/- 1.02) x 10(-6) cm x s(-1) from the BL side to AP side, respectively. The P(appAP --> BL)/P(app BL --> AP) ratio of wogonoside and wogonin were 0.58 and 1.49, respectively. Baicalin, baicalein and glycyrrhizic acid could not permeate the Caco-2 cell model.</p><p><b>CONCLUSION</b>The transportation of wogonoside and wogonin in Caco-2 cell model may be a passive transportation.</p>