Absorption, Distribution, and Elimination of 14c-dodecamethylcyclohexasiloxane in Rats Following Oral Administration, with Cover Letter dated 4/20/94

摘要

This study evaluated the absorption, distribution, and excretion of dimethyl cyclosiloxane fluids by the oral route in rats. Two Sprague Dawley rats were given a single oral gavage dose of the radiolabeled test substance at a dose of 600 mg/kg and placed in a Roth-type metabolism chamber. Expired air and excreta were collected for 72 hours. Urine and feces were collected at 24 hour intervals and radioactivity determined using liquid scintillation spectrometry. Expired air was passed over activated charcoal to trap metabolites and radioactivity was determined using liquid scintillation spectrometry. After obtaining the last urine sample, the animals were sacrificed and plasma and tissues were collected for total radioactivity analyses. No signs of systemic toxicity were noted. Approximately 53 and 86 percent of the total radioactivity was eliminated in the first 24 and 48 hours, respectively. Approximately 75 percent of the total radioactivity was eliminated in the feces, 13 percent in the expired air, and 2 percent in the urine. Trace amounts of radioactivity were seen in the liver, lungs, kidney, heart, and gastrointestinal tract. Based on the amount of total recovered radioactivity, approximately 15 percent of the administered dose was absorbed from the gastrointestinal tract.