Biliary metabolites and enterohepatic circulation of hexachlorophene in the rat

1. Within 0-5 h after intraperitoneal administration of [¹⁴C]hexachlorophene to rats, radioactivity appeared in the bile. Over 2.5-3.0 days, 31% and 47% of administered doses of 5 mg/kg and 10 mg/kg, respectively, were eliminated via this route. 2. Ligation of the bile-duct increased the toxicity of hexachlorophene to rats and also caused the major route of excretion to be via the kidney into the urine (55% of the dose). 3. Extensive enterohepatic circulation of hexachlorophene occurs in the rat. 4. The principal metabolite in bile and in the urine of bile-duct ligated rats was hexachlorophene monoglucuronide, along with small amounts of unchanged drug.