Pharmacokinetic Data of Bromofenofos in Calves

Abstract

Bromofenofos (BF) was administered orally to six calves at a dose of 12mg/kg and the concentrations of BF and its metabolite dephosphace bromofenofos (DBF) in plasma were determined using a high-performance liquid chromatographic method. DBF reached maximum concentration of 45.9 f 16.3 pg/ml, which occurred at 1.3 ? 0.4 days. The elimination half life was calculated to be 1.8 kO.3 days and the area under the plasma concentration versus time curve was 185.1 f 49.4 pg . day/ml. The ultrafiltrate of plasma samples revealed no free metabolite, indicating a binding of > 9 9 % to plasma protein. DBF disappeared from plasma in all calves 21 days after administration. No BF was detected in plasma at any time.