Studies on the toxicology of hexachlorobenzene. I. Pharmacokinetics

In female rats dosed orally with 14C-hexachlorobenzene the extent of intestinal absorption of carbon-14 has been found to be dependent on the form of application. When the substance was given as a solution in oil about 80% of the dose administered was absorbed, but when given as an aqueous suspension only 6%. In animals treated with 14C-hexachlorobenzene dissolved in oil, all tissues contained radioactivity. Highest levels were found in adipose tissue, lowest in blood and muscle. Peak values of radioactivity were reached between 2 to 5 days after application. Elimination was studied after intraperitoneal application of 4 mg/kg14C-hexachlorobenzene dissolved in oil. Two weeks after administration, 34% of the radioactivity administered was recovered in the feces and 5% in urine. About 80% of carbon-14 excreted in feces and about 4% in urine was contained in the unchanged drug. This indicates that biodegradation of hexachlorobenzene in the rat is not insignificant. No radioactivity was detected in the expired air.