Pharmacokinetic data of bromofenofos in calves

Bromofenofos (BF) was administered orally to six calves at a dose of 12 mg/kg and the concentrations of BF and its metabolite dephosphate bromofenofos (DBF) in plasma were determined using a high-performance liquid chromatographic method. DBF reached maximum concentration of 45.9 +/- 16.3 micrograms/ml, which occurred at 1.3 +/- 0.4 days. The elimination half life was calculated to be 1.8 +/- 0.3 days and the area under the plasma concentration versus time curve was 185.1 +/- 49.4 micrograms.day/ml. The ultrafiltrate of plasma samples revealed no free metabolite, indicating a binding of greater than 99% to plasma protein. DBF disappeared from plasma in all calves 21 days after administration. No BF was detected in plasma at any time.