title: Pharmacokinetics of mequindox and one of its major metabolites in chickens after intravenous, intramuscular and oral administration.
abstract: Pharmacokinetics of mequindox and one of its major metabolites (M) was determined in chickens after intravenous (i.v.), intramuscular (i.m.) and oral administration of mequindox at a single dose of 10 (i.v. and i.m.) or 20 mg/kg b.w. (oral). Plasma concentration profiles were analyzed by a non-compartmental pharmacokinetic method. Following i.v., i.m. and oral administration, the areas under the plasma concentration-time curve (AUC(0-∞)) were 0.71±0.15, 0.67±0.21, 0.25±0.10 μg h/mL (mequindox) and 37.24±7.98, 36.40±9.16, 86.39±16.01 μg h/mL (M), respectively. The terminal elimination half-lives (t(1/2λz)) were determined to be 0.15±0.06, 0.21±0.09, 0.49±0.23 h (mequindox) and 5.36±0.86, 5.39±0.52, 5.22±0.35 h (M), respectively. The bioavailabilities (F) of mequindox were 89.4% and 16.6% for i.m. and oral administration. Steady-state distribution volume (V(ss)) of 1.20±0.34 L/kg and total body clearance (Cl(B)) of 13.57±2.16 L/kg h were determined for mequindox after i.v. dosing. After single i.m. and oral administration, peak plasma concentrations (C(max)) of 3.04±1.32, 0.36±0.13 μg/mL (mequindox) and 3.81±0.92, 5.99±1.16 μg/mL (M) were observed at t(max) of 0.08±0.02, 0.32±0.12 h (mequindox) and 0.66±0.19, 6.67±1.03 h (M), respectively. The results showed that mequindox was rapidly absorbed after i.m. or p.o. administration and most of mequindox was transformed to metabolites in chickens, with much higher C(max)s and AUCs of metabolite (M) than those of mequindox in plasma.
authors.affiliation: Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, PR China.
authors.forename: Huanzhong
authors.initials: H
authors.lastname: Ding
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhenling
authors.initials: Z
authors.lastname: Zeng
authors.forename: Hongbin
authors.initials: H
authors.lastname: Si
authors.forename: Kaiyong
authors.initials: K
authors.lastname: Liu
authors.forename: Yiming
authors.initials: Y
authors.lastname: Liu
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Yafei
authors.initials: Y
authors.lastname: Li
authors.forename: Dongping
authors.initials: D
authors.lastname: Zeng
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002645:Chickens / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D007273:Injections, Intramuscular / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D011810:Quinoxalines / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: C545385:Mequindox; D011810:Quinoxalines