Comparative pharmacokinetics of enrofloxacin, danofloxacin and marbofloxacin following intramuscular administration in sheep

• Flouroquinolonesare licensed in many countries for the use in animals.
• We compared the pharmacokinetic profiles of severalflouroquinolonesin sheep.
• No clinical adverse response was observed during the study.
• Marbofloxacin was found better to reach the maximum concentration in plasma.

The aim of this study was to determine and compare the pharmacokinetic profiles of enrofloxacin (ENF), danofloxacin (DNF) and marbofloxacin (MBF) after intramuscular administration in sheep. A total of 18 cross-bred healthy sheep were used in the study. The animals were allocated into three groups of six such that the mean weight of animals in each group was similar. In Group I (ENF) was given intramuscularly at a dose rate of 2.5 mg/kg, in Group II (DNF) was given intramuscularly at a dose rate of 1.25 mg/kg and in Group III (MBF) was given intramuscularly at a dose rate of 2 mg/kg. Heparinized blood samples were collected between 0.5 and 48 h after treatment.The results indicated that MBF produced a significantly higher maximum plasma concentration (Cmax:1.43 ± 0.50 μg/ml) with quicker absorption (tmax: 1.00 ± 0.00) and larger area under the concentration vs. time curve (AUC: 8.36 ± 2.58 μg h/ml) as compared with ENF (Cmax: 0.88 ± 0.13 μg/ml, tmax: 1.66 ± 0.47, AUC: 5.64 ± 2.52 μg h/ml) and DNF (Cmax: 0.70 ± 0.08 μg/ml, tmax: 1.33 ± 0.23, AUC: 3.00 ± 0.65 μg h/ml) following intramuscular administration of drugs. Similarly, the mean residence time (MRT: 6.37 ± 0.59) and the half-life (t1/2λz: 9.50 ± 1.86) was significantly longer MBF group than ENF (MRT: 4.54 ± 0.79, t1/2λz: 3.06 ± 0.39) and DNF (MRT: 4.04 ± 0.17, t1/2λz: 3.52 ± 0.22) groups.In this study, regarding ENF, DNF and MBF, three of fluoroquinolones antibacterial agents with common usages in sheep at recommended doses, with intramuscular administration were compared in pharmacokinetic parameters and as a result, marbofloxacin was found significantly the highest in rate to reach the maximum concentration in plasma.