Serum and Urine Levels of Ethchlorvynol in Man

Abstract

Serum and urine levels of ethchlorvynol were determined by gas chromatography using electron-capture detection. The method is sensitive to 0.25 mcg./ml. and reproducible within 2% relative standard deviation. In 25 hr., 0.025% of the total dose is excreted unchanged or as the glucuronide. Peak serum levels of 2.5, 6.5, or 8.0 mcg./ml. are seen at 1 hr. after administration of 200,500, or 750-mg. capsules, respectively. The decline of the serum levels is biphasic, with disappearance constants of 0.5 and 0.03 hr.−1. When the data are interpreted in terms of a two-compartment model, therate constant for elimination is calculated to be 0.13 hr.−1. The ratio of the amount of ethchlorvynol in the tissue compartment to that in the central compartment is 3.5:1.