Pharmacokinetics of florfenicol in the plasma of Japanese quail.

AIM

To determine the pharmacokinetics and bioavailability of florfenicol in the plasma of healthy Japanese quail (Coturnix japonica).

METHODS

Sixty-five quail were given an I/V and I/M dose of florfenicol at 30 mg/kg bodyweight (BW). A two-period sequential design was used, with a wash-out period of 2 weeks between the different routes of administration. Concentrations of florfenicol in plasma were determined using high-performance liquid chromatography (HPLC).

RESULTS

A naïve pooled data analysis approach for the plasma concentration-time profile of florfenicol was found to fit a non-compartmental open model. After I/V administration, the mean residence time (MRT), mean volume of distribution at steady state (Vss), and total body clearance of florfenicol were 12.0 (SD 0.37) h, 8.7 (SD 0.22) L/kg, and 1.3 (SD 0.08) L/h/ kg, respectively. After I/M injection, the MRT, mean absorption time (MAT), and bioavailability were 12.3 (SD 0.37) h, 0.2 (SD 0.02) h, and 79.1 (SD 1.79)%, respectively.

CONCLUSIONS

The time for the concentration of florfenicol to fall below the probable effective concentration of 1 microg/ ml of approximately 10 h is sufficient for the minimum inhibitory concentration needed for many bacterial isolates. Further pharmacodynamic studies in quail are needed to evaluate a suitable dosage regimen.