DISPOSITION OF METRONIDAZOLE IN HENS (GALLUS-GALLUS) AND QUAILS (COTURNIX-COTURNIX-JAPONICA) - PHARMACOKINETICS AND WHOLE-BODY AUTORADIOGRAPHY

Hens were given single intravenous or oral doses (30 mg/kg body weight ) of metronidazole and the plasma concentrations of the drug were dete rmined by high-performance liquid chromatography (HPLC) at intervals f rom 10 min to 24 h after drug administration. Pharmacokinetic variable s were calculated by the Lagrange algorithm technique. The elimination half-life (t(1/2 beta)) after the intravenous injection was 4.2 +/- 0 .5 h, the volume of distribution (V-d(ss)) 1.1 +/- 0.2 L/hg and the to tal body clearance (Cl-beta) 131.2 +/- 20 mL/h . kg. Oral bioavailabil ity of the metronidazole was 78 +/- 16%, The plasma maximum concentrat ion (C-max) 31.9 +/- 2.3 mu g/mL was reached 2 h after the oral admini stration and the oral elimination half-life (t(1/2 beta)) was 4.7 +/- 0.2 h, The binding of metronidazole to proteins in hen plasma was very low (less than 3%). Whole body autoradiography of [H-3] metronidazole in hens and quails showed an even distribution of labelled material i n various tissues at short survival intervals (1 - 4 h) after oral or intravenous administration. A high labelling was seen in the contents of the small and large intestines. In the laying quails a labelling wa s also seen in the albumen and in a ring in the periphery of the yolk at long survival intervals. Our results show that a concentration twof old above the MIC is maintained in the plasma of hens for at least 12 h at an oral dose of 30 mg/kg metronidazole.