Pharmacokinetics of gemifloxacin following intravenous and oral administration in layer birds

The present study was planned to determine single dose pharmacokinetics of gemifloxacin following intravenous and oral administration in layer birds at the rate of 10 mg/kg of body. Gemifloxacin concentrations in plasma were assayed by Liquid chromatography with mass spectrometry (LC-MS/MS). Following intravenous administration of gemifloxacin in layer birds, the concentration of gemifloxacin (e” 120 ng/mL) was maintained up to 6 h and was detected (28.60 ± 0.38 ng/mL) in plasma up to 12 h. Following oral administration mean peak plasma gemifloxacin concentration (C_max) of 181.71 ± 3.80 ng/mL was achieved at 4 h (T_max). Based on the plasma gemifloxacin concentrations following intravenous administration, various pharmacokinetics parameters like elimination rate constant (Kel: 0.28 ± 0.004 h⁻¹), half-life (T_½: 2.50 ± 0.04 h), area under plasma gemifloxacin concentration-time curve (AUC_0-σ: 4927.69 ± 67.55 ng.h/mL), area under first moment curve (AUMC_0-σ: 11006.20 ± 140.74 ng.h²/mL), apparent volume of distribution (Vd_area: 10601.52 ± 359.82 mL), volume of distribution at steady-state (Vd_ss: 6561.87 ± 230.12 mL), total body clearance (Cl_B: 2935.95 ± 92.05 mL/h) and mean residence time (MRT: 1.95 ± 0.01 h) were determined. Following oral administration, various pharmacokinetics parameters like Kel: 0.30 ± 0.004 h⁻¹, T_½: 2.35 ± 0.03 h, AUC_0-σ: 870.18 ± 14.81 ng.h/mL, AUMC_0-σ: 4969.77 ± 97.86 ng.h²/mL, Vd_area: 61888.73 ± 3151.53 mL, Cl_B: 18244.54 ± 863.51 mL/h, MRT: 5.01 0.01 h and bioavailability (F: 15.50 ± 0.90%.) were determined.