Marbofloxacin pharmacokinetics in goats during the lactation

Abstract

The purposes of this study were to compare the pharmacokinetic profile of marbofloxacin and antibiotic penetration from blood to milk after intramuscular administration in goats at the beginning, at the peak milk yield and at the end of lactation and to apply the PK/PD modelling approach, so that effective dosage recommendations for this specie could be made. Five healthy lactating goats at 4–9; 25–30 and 150–155 days postpartum were used. At each experience 2 mg/kg intramuscular marbofloxacin was administered. Plasma and milk samples were obtained. Marbofloxacin concentrations were determined by microbiological assay using Klebsiella pneumoniae ATCC 10031 as test microorganism. Plasma pharmacokinetic parameters were calculated from the individual disposition curves, and significant differences between the different moments of lactation were found for AUC (significantly larger for the end of lactation vs the others moments). Milk concentrations were detected for 12 hs postadministration. Our results show that the lactation stage modified the pharmacokinetic profile of marbofloxacin, however these differences are of little consequence from a practical point of view. Volume of milk produced modified milk concentrations of marbofloxacin. A 2 mg/Kg dose level of marbofloxacin would be effective for treating microorganisms with MIC lower than 0.04 μg/mL as E. coli or P. multocida.