ABSTRACT
<p><b>OBJECTIVE</b>To investigate the absolute bioavailability of caffeic acid in rats and its intestinal absorption properties.</p><p><b>METHOD</b>The absolute bioavailability (Fabs) of caffeic acid was obtained after iv (2 mg x kg(-1)) or ig (10 mg x kg(-1)) administration to rats. The intestinal absorption of caffeic acid was explored by the recirculating vascularly perfused rat intestinal preparation. Caco-2 cell model was applied to measure the permeability of caffeic acid from apical to basolateral said (A-B) and from basolateral to apical said (B-A).</p><p><b>RESULT</b>A two-compartment pharmacokinetic model was best to describe the pharmacokinetics of caffeic acid following iv or ig administration. The Fabs of caffeic acid was 14. 7% , and its intestinal absorption was 12.4%. The values of Papp A-->B and Papp B-->A of caffeic acid were retained stable while its concentration was changed. The efflux ratio values in this study surveyed were above 2.0, and suggesting caffeic acid was active transport.</p><p><b>CONCLUSION</b>Caffeic acid was shown to have poor permeability across the Caco-2 cells, low intestinal absorption and low oral bioavailability in rats.</p>