Comparative Pharmacokinetics of Orbifloxacin Following a Single Intravenous or Oral Administration to Healthy and Diabetic Rats

Abstract

The single-dose disposition kinetics of orbifloxacin was determined in clinically healthy and diabetic rats  after intravenous or oral administration of 5 mg/kg body weight. Orbifloxacin concentrations were determined  by HPLC with fluorescence detection. The HPLC method was sensitive, specific and repeatable. A  systemic bioavailability of 99.1% and 108 %, and a Cmax of 6.55 } 1.09 μg /mL and 8.63 } 1.09 μg /mL were  observed in healthy and diabetic rats, respectively. The terminal half-life after intravenous and oral administration  was 4.17 } 0.38 h and 4.03 } 0.41 h for healthy and 2.31 } 0.34 h and 3.03 } 0.28 h for diabetic  rats. Orbifloxacin was cleared more rapidly in diabetic rats (0.15 } 0.01 L/kg.h) than healthy group (0.11 }  0.01 L/kg.h), with longer mean resident time (MRT) values observed in the latter. Other kinetic parameters  were almost the same between the healthy and diabetic groups. This investigation revealed that a dose of 5  mg/kg orbifloxacin can be safely and effectively used to combat infections in rats of either group associated  with susceptible bacteria.