Pharmacokinetic evaluation of marbofloxacin following single and repetitive intravenous administration in Rabbits

Pharmacokinetic study of marbofloxacin was carried out in rabbits following single and repetitive intravenous (IV) administration. Serial blood samples were taken from days 1^st and 5^th of marbofloxacin administration. Concentrations of the marbofloxacin in blood plasma were estimated by microbiological assay techniques. Various kinetic parameters were calculated by using two compartment open model. Significantly higher plasma concentrations of the drug appeared from 0.5 to 12 hr on 5^th day as compared to 1^st day of marbofloxacin administration. The minimum therapeutic concentration (≥ 0.25 µg/ml) of marbofloxacin was maintained up to 12 hr in both 1^st and 5^th day of drug administration. Following multiple once IV dose, significantly higher values of t_1/2β, and AUC were observed in 5^th day as compared to 1^st day of marbofloxacin administration, whereas significantly lower value of Vd_area and Cl_B were observed in 5^th day as compared to 1^st day of marbofloxacin administration. All the other kinetic parameters differ non-significantly between 1^st and 5^th day of marbofloxacin administration. On the basis of present findings a satisfactory dosage regimen of marbofloxacin @ 0.91±0.03 mg/kg bwt followed by 0.71±0.03 mg/kg bwt at 12 hr intervals can be recommended to maintain the minimum therapeutic concentration (≥ 0.25 µg/ml)) during the treatment of microbial infections in rabbit.

• Significantly higher plasma concentrations of the marbofloxacin appeared from 0.5 to 12 hr on 5^th day as compared to 1^st day of drug administration.

• The minimum therapeutic concentration of marbofloxacin was maintained up to 12 hr in both 1^st and 5^th day of drug administration.