Pharmacokinetics of moxifloxacin in buffalo calves after single subcutaneous administration

Abstract

The pharmacokinetics and urinary excretion of moxifloxacin was investigated in buffalo calves following a single subcutaneous administration (5 mg/kg b.wt.). Moxifloxacin concentrations in plasma and urine were estimated by microbiological assay technique using E. coli as test organism. Pharmacokinetic analysis of disposition data indicated that subcutaneous administration data were best described by 1-compartment open model. The peak plasma levels of moxifloxacin were 2.06±0.07 µg/ml at 45 min and the drug was detected up to 12 h. The absorption half-life and elimination half-life were 1.06±0.43 h and 2.72±0.24 h, respectively. The apparent volume of distribution and total body clearance were 1.48±0.14 L/kg and 378±14.8 ml/kg/h, respectively. The urinary excretion of moxifloxacin in 24 h was 10.2±0.94% of total administrated dose. From the data of surrogate markers (AUC/MIC, Cmax/MIC), it was determined in the buffalo calves that when administered by the subcutaneous route @ 5 mg/kg, moxifloxacin is likely to be effective against bacterial isolates with MIC < 0.09 µg/ml.