title: Bioavailability and pharmacokinetics of florfenicol in healthy sheep.
abstract: A study on bioavailability and pharmacokinetics of florfenicol was conducted in 20 crossbred healthy sheep following a single intravenous (i.v.) and intramuscular (i.m.) doses of 20 and 30 mg/kg body weight (b.w.). Florfenicol concentrations in serum were determined by a validated high-performance liquid chromatography method with UV detection at a wavelength of 223 nm in which serum samples were spiked with chloramphenicol as internal standard. Serum concentration-time data after i.v. administration were best described by a three-compartment open model with values for the distribution half-lives (T(1/2alpha)) 1.51 +/- 0.06 and 1.59 +/- 0.10 h, elimination half-lives (T(1/2beta)) 18.83 +/- 6.76 and 18.71 +/- 1.85 h, total body clearance (Cl(B)) 0.26 +/- 0.03 and 0.25 +/- 0.01 L/kg/h, volume of distribution at steady-state (V(d(ss))) 1.86 +/- 0.11 and 1.71 +/- 0.20 L/kg, area under curve (AUC) 76.31 +/- 9.17 and 119.21 +/- 2.05 microg.h/mL after i.v. injections of 20 and 30 mg/kg b.w. respectively. Serum concentration-time data after i.m. administration were adequately described by a one-compartment open model. The pharmacokinetic parameters were distribution half-lives (T(1/2k(a) )) 0.27 +/- 0.03 and 0.25 +/- 0.09 h, elimination half-lives (T(1/2k(e) )) 10.34 +/- 1.11 and 9.57 +/- 2.84 h, maximum concentrations (C(max)) 4.13 +/- 0.29 and 7.04 +/- 1.61 microg/mL, area under curve (AUC) 67.95 +/- 9.61 and 101.95 +/- 8.92 microg.h/mL, bioavailability (F) 89.04% and 85.52% after i.m. injections of 20 and 30 mg/kg b.w. respectively.
authors.affiliation: Department of Pharmacology and Toxicology, College of Veterinary Medicine, China Agriculture University, Beijing, China.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Shen
authors.forename: Xiubo
authors.initials: X
authors.lastname: Li
authors.forename: Haiyang
authors.initials: H
authors.lastname: Jiang
authors.forename: Walter H
authors.initials: WH
authors.lastname: Hsu
authors.forename: S
authors.initials: S
authors.lastname: Jianzhong
authors.forename: L
authors.initials: L
authors.lastname: Xiubo
authors.forename: J
authors.initials: J
authors.lastname: Haiyang
authors.forename: H H
authors.initials: HH
authors.lastname: Walter
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D007273:Injections, Intramuscular / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D011897:Random Allocation; D012756:Sheep / Q000378:metabolism*; D013839:Thiamphenicol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D019155:Veterinary Drugs / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics
chemical_list: D000900:Anti-Bacterial Agents; D019155:Veterinary Drugs; C035534:florfenicol; D013839:Thiamphenicol