Oral and intravenous trichloroethylene pharmacokinetics in the rat

The pharmacokinetics of trichloroethylene (TCE) was studied in male 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 (V beta) and total body clearance (CLT) decreased with increase in dose. The terminal half-life (t1/2) 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 t1/2 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.