Bioavailability and pharmacokinetics of florfenicol in broiler chickens

Abstract

The bioavailability and pharmacokinetic disposition of florfenicol in broiler chickens were investigated after intravenous (i.v.), intramuscular (i.m.) and oral administrations of 15 and 30 mg/kg body weight (b.w.). Plasma concentrations of florfenicol were determined by a high performance liquid chromatographic method in which plasma samples were spiked with chloramphenicol as internal standard. Plasma concentration-time data after i.v. administration were best described by a two-compartment open model. The elimination half-lives were 168 +/- 43 and 181 +/- 71 min, total body clearance 1.02 +/- 0.17 and 1.02 +/- 0.16 L x kg/h, the volume of distribution at steady-state 4.99 +/- 1.11 and 3.50 +/- 1.01 L/kg after i.v. injections of 15 and 30 mg/kg b.w., respectively. Plasma concentration-time data after i.m. and oral administrations were adequately described by a one-compartment model. The i.m. bioavailability and the oral bioavailability of florfenicol were 95, 98 and 96, 94%, respectively, indicating that florfenicol was almost absorbed completely after i.m. and oral administrations of 15 and 30 mg/kg b.w.

Comparative Pharmacokinetics of Tylosin or Florfenicol after a Single Intramuscular Administration at Two Different Doses of Tylosin-Florfenicol Combination in Pigs

“…Consistent with a similar study in broiler chicken [13], change in the dose of florfenicol had no effect on T max . However, the changes in the peak concentration of both drugs were not proportional to changes in dose, in which a relatively lower absorption of both drugs was observed at higher doses.…”

“…However, the changes in the peak concentration of both drugs were not proportional to changes in dose, in which a relatively lower absorption of both drugs was observed at higher doses. A similar non-proportional increase of C max with change in dose of oral florfenicol was observed in broiler chicken [13]. The lower peak concentration and AUC seen at higher concentration may concern residues at the injection site, though we are at the early stage to support with data the idea that residues should be considered more in combination therapy than in single therapy.…”

“…No significant difference in all pharmacokinetic parameters was observed between the two dose levels of tylosin. The experimental data in this study was best fitted to a one compartment model in accordance with previous reports in different animals [7,13,15], though other authors preferred a non compartmental model for the same route of administration [5,9]. The elimination half life of tylosin 10 mg/kg in this study (3.01 ± 2.77 hr) is higher than the reported figures in cattle and buffaloes (2.24 and 2.4 hr, respectively) [12], but significantly lower than observations in pig [9], in the latter the mean elimination half life (T 1/2eli ) of five pigs was calculated to be greater than 24 hr.…”

Pharmacokinetics and Bioequivalence of Florfenicol Oral Solution Formulations (Flonicol® and Veterin®10%) in Broiler Chickens

“…Florfenicol has been approved and become a valuable antibacterial in the treatment of serious bacterial infections in farm animals [16,27]. In poultry, florfenicol is used extensively for the twreatment of respiratory and gastrointestinal bacterial infections, administered via drinking water [7,17,24].…”

“…However, to date, studies on the efficacy of florfenicol using pharmacokinetic/ pharmacodynamic (PK/ PD) approaches have not been carried out in poultry. Nevertheless, the pharmacokinetics and bioavailability of florfenicol have been investigated in broiler chickens [15][16][17], turkeys [7] and ducks [18]. Most of these studies used the same original preparation of florfenicol.…”