Biliary excretion of diazepam in rats: influence of the route of administration and dosage.

The biliary excretion of diazepam metabolites was found in rats. Equivalent dosages of diazepam were administered orally and intraperitoneally. The biliary excretion was dose-dependent and was greater following intraperitoneal administration. After intravenous administration, a greater percentage of the diazepam dosage administered was excreted into the bile. Repetitive intravenous administrations yielded results which approached those observed after intraperitoneally administered dosages given as a bolus.