Abstract

Marbofloxacin (MBX) is a fluoroquinolone applied only in domestic animals. It exhibits favorable kinetic properties and excellent activity against gram-negative microorganisms and mycoplasmas. This study was to determine kinetic parameters after the single application of MBX (Marbocyl 10%, Vetoquinol, Spain) and to evaluate its therapeutic usefulness. Twelve healthy calves of 29 ± 5 days of age, 46.4 ± 10.5 kg of body weight, clinically healthy, received a single 6 mg / kg dose of marbofloxacin intramuscularly. At different times up to 24 hours post-application blood samples were taken in heparinized tubes, centrifuged and stored until analyzed by HPLC. The preparative test consisted in the extraction of the analyte using 200 µL of sample, 200 µL of water, 800 µL of methanol and enrofloxacin as an internal standard. The assembly was stirred for 30” in vortex and then centrifuged 25 minutes at 13.500 rpm at 4 ° C. Separation and quantification was performed by isocratic elution in reverse phase using C-18 column and fluorescence detector reading set at 295 nm excitation and 490 nm emission, mobile phase composed of water, acetonitrile and triethylamine (79: 19: 1 v / v / v) at pH 3. Plasma concentration data were analyzed by PK Solution 2.0 software to calculate robust kinetic parameters. Intramuscular administration determines prompt absorption, Cmax of 5.0 ± 1.5 μg / ml obtained at 1.7 ± 1.01 hours. MBX exhibits moderate tissue distribution, extensive permanence in the organism according to the parameters of Vdarea and TMR. The results obtained agree with the kinetic profile demonstrated by MBX in domestic animals and suggests its application in infectious diseases caused by germs with MIC ≤ 0.13 μg / ml, according to predictors of efficacy used for fluoroquinolones, ABC /CMI and Cmax / CMI