PHARMACOKINETIC AND THERAPEUTIC STUDIES ON DANOFLOXACIN AND MARBOFLOXACIN IN LACTATING COWS

Abstract

A single dose of danofloxacin (Advocin, 1.25 mg/kg b.w.) or marbofloxacin (Marbocyl, 2 mg/kg b.w.) were injected intramuscularly to ten dairy cows between 3.5 and 6.5 years old and weighing 500-580 kg for the evaluation of their plasma and milk concentrations and antibacterial characteristics against common mastitis pathogens. Blood and milk samples were collected for determination of concentrations of two drugs by HPLC method. It was shown that the passage of the two drugs from blood into milk was rapid and extensive, especially danofloxacin, where at 4 and 8 h, its milk concentration was 2.4 and 4.2 times higher than the plasma concentration, respectively. For marbofloxacin it was 1.15 and 1.14 at the same times, respectively. Danofloxacin concentrations were maintained in the cow's milk at equal to or higher than the MIC90 of Escherichia coli (0.06 µg/ml) and Mycoplasma spp. (0.008-0.5 µg/ml) for 24 h and of Staphylococcus aureus (0.18 µg/ml) for 12 h. The marbofloxacin concentrations were still equal to or higher than the MIC90 of E. coli (0.016 µg/ml) for 24 h and of S. aureus (0.229 µg/ml) and Mycoplasma spp. (0.48 µg/ml) for nearly 8 h.