The plasma pharmacokinetics of iophenoxic and iopanoic acids in goat

Abstract

1. The comparative plasma pharmacokinetics of two organic iodine-containing compounds were evaluated in the goat for their suitability as markers in wildlife studies.

2. After oral administration of a single dose, the plasma elimination half-life for iopanoic acid was considerably more rapid (t_1/2 of 1–2 days) than that of iophenoxic acid (t_1/2 of 81 days).

3. Similar peak plasma concentrations were obtained after administration of iophenoxic acid (1.5 mg/kg) and iopanoic acid (25 mg/kg); however, the AU_{0 → ∞} for iopanoic acid at doses of 25, 50, and 100 mg/kg were 201 ± 39, 604 ± 225, and 1292 ± 721 (μg h/ml ± SD), respectively, which were less than the value of 36 600 ± 6387 for the oral administration of iophenoxic acid at 1.5 mg/kg.

4. Iophenoxic acid was chosen as a suitable marker because of its persistence at detectable concentrations in the plasma for 5 months.