title: Bioavailability of amprolium in fasting and nonfasting chickens after intravenous and oral administration.
abstract: The bioavailability of amprolium (APL) was measured after intravenous (i.v.) and oral (p.o.) administration to chickens. Twelve healthy chickens weighing 1.28-1.41 kg received a dose of 13 mg APL/kg intravenously, and 13 or 26 mg APL/kg orally in both a fasted and a nonfasted condition in a Latin square design. Plasma samples were taken from the subwing vein for determination of APL concentration by HPLC method. The data following intravenous and oral administration were best fitted by 2-compartment and 1-compartment models, respectively, using weighted nonlinear least squares regression. The half-life beta t(1/2)beta, volume of distribution (Vd) and total body clearance (Cl) after intravenous administration were 0.21 h, 0.12 L/kg and 1.32 L/h.kg, respectively. The elimination half-life (t(1/2) Kel) after oral administration was 0.292-0.654 h which is 1.5-3.2 times longer than after intravenous administration, suggesting the presence of a 'flip-flop' phenomenon in chickens. The maximum plasma concentration (Cmax) of 13 mg/kg APL administered orally to chickens during fasting was significantly (about four times) higher than that during nonfasting (P < 0.05). Bioavailability during nonfasting was from 2.3 to 2.6%, and 6.4% during fasting.
authors.affiliation: National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, Tokura 1-15-1, Kokubunji-shi, Tokyo 185-, 8511, Japan. hamamok@nval.go.jp
authors.forename: K
authors.initials: K
authors.lastname: Hamamoto
authors.forename: R
authors.initials: R
authors.lastname: Koike
authors.forename: Y
authors.initials: Y
authors.lastname: Machida
mesh_terms: D000284:Administration, Oral; D000670:Amprolium / Q000493:pharmacokinetics*; D000818:Animals; D001682:Biological Availability; D002645:Chickens; D003049:Coccidiostats / Q000493:pharmacokinetics*; D005215:Fasting; D005260:Female; D007262:Infusions, Intravenous; D011201:Poultry Diseases / Q000188:drug therapy*
chemical_list: D003049:Coccidiostats; D000670:Amprolium