Pharmacokinetics and tissue disposition of danofloxacin in sheep

The plasma pharmacokinetics of danofloxacin administered at 1.25 mg kg−1 body weight by the intravenous and intramuscular routes were determined in sheep. Tissue distribution was also determined following administration by the intramuscular route at 1.25 mg kg−1 body weight. Danofloxacin had a large volume of distribution at steady state (V dss) of 2.76±0.16 h (mean±S.E.M.) L kg−1, an elimination half‐life (t1/2β) of 3.35±0.23 h, and a body clearance (C1) of 0.63±0.04 L kg−1 h−1. Following intramuscular administration it achieved a maximum concentration (Cmax) of 0.32±0.02 μg mL−1 at 1.23±0.34 h (tmax) and had a mean residence time (MRT) of 5.45±0.19 h. Danofloxacin had an absolute bioavailability (F) of 95.71±4.41% and a mean absorption time (MAT) of 0.81±0.20 h following intramuscular administration. Mean plasma concentrations of >0.06 μg mL−1 were maintained for more than 8 h following intravenous and intramuscular administration. Following intramuscular administration highest concentrations were measured in plasma (0.43±0.04 μg mL−1), lung (1.51±0.18 μg g−1), and interdigital skin (0.64±0.18 μg g−1) at 1 h, duodenal contents (0.81±0.40 μg mL−1), lymph nodes (4.61±0.35 μg g−1), and brain (0.06±0.00 μg mL−1) at 2 h, jejunal (10.50±4.31 μg mL−1) and ileal (5.25±1.67 μg mL−1) contents at 4 h, and colonic contents (8.94±0.65 μg mL−1) at 8 h. © 1998 John Wiley & Sons, Ltd.