Transport of phenobarbitone into the intestinal lumen and the biliary tract following i.v. administration to rats

Abstract

Abstract The exsorption of intravenously administered phenobarbitone into the lumen of the small intestine of rats has been examined by an in-situ single-pass perfusion technique. The levels of the drug in the bile were about twice that in serum. Moreover, it was shown that the drug was appreciably exsorbed into the intestinal lumen. The exsorption rates of the drug into the perfusates were not very different between isotonic phosphate buffers at pH 6.0 and 8.0. The amounts of phenobarbitone exsorbed into the perfusate and excreted into the bile were 6.47 and 0.45% of the dose for isotonic phosphate buffer at pH 6.0, and were 6.09 and 0.54% of the dose for isotonic phosphate buffer at pH 8.0.