Oral and intravenous trichloroethylene pharmacokinetics in the rat

Abstract
The pharmacokinetics of trichloroethylene (TCE) was studied in wale Sprague‐Dawley rats (300–350 g). TCE was administered intravenously and orally at doses of 5, 10, and 25 mg/kg to nonfasted rats and orally at 10 mg/kg to rats fasted for 8–10 h. The disappearance of TCE from the blood of intravenously dosed animals was best described by a two‐compartment open pharmacokinetic model. The volume of the central compartment (VC) approximated the rats’ blood volume (50–70 ml/kg). The volume distribution (Vβ) and total body clearance (CLT) decreased with increase in dose. The terminal half‐life (t½>) was about 120 min and was not affected by increases in dose. TCE was rapidly absorbed after oral dosing, with blood concentrations peaking between 6 and 10 min. The oral to intravenous bioavailability of TCE was 60–80% in nonfasted animals. The terminal t½> in fasted, orally dosed rats was identical to that when fasted rats were given the same dose intravenously. In fasted rats, bioavailability of an oral dose was greater than 90%, and peak levels in the blood were 2–3 times as high as in nonfasted rats.