Is there an effect of food on the biliary secretion of cyclosporine and three in vivo formed metabolites in a porcine model?

The aim of this study was to investigate the effect of lipids and P-glycoprotein (P-gp) inhibition on the biliary secretion of cyclosporine (CsA) and in vivo formed metabolites in pigs. A parallel group design including 12 pigs in four groups and a combined single-pass intestinal perfusion and bile collection method was employed. CsA was perfused through the jejunum in an isotonic fluid alone and with verapamil or lipids added. The study showed that there was no difference between the administration groups, except for the fraction of the absorbed dose that was excreted in bile was twice as high when CsA was administered together with lipids. In conclusion, CsA is excreted via the biliary route in pigs without any significant involvement of P-gp. Concomitant food-intake could increase the secretion to the bile, presumably by prolonged associations between the CsA and the lipid species.