Pharmacokinetics of marbofloxacin following intramuscular administration at different doses in sheep

Rapid determination of marbofloxacin by surface-enhanced Raman spectroscopy of silver nanoparticles modified by β-cyclodextrin

A novel surface enhanced-Raman spectroscopy (SERS) assay for marbofloxacin was developed based on β-cyclodextrin-modified silver nanoparticles (β-CD-AgNPs). The marbofloxacin could interact with β-CD-AgNPs and a new assembly was formed by AgN covalent bond. This assembly was characterized by the spectra of FT-IR and UV-vis. The optimal measurement conditions were studied in detail. In 0.033 mol L^-1 HCl solution, marbofloxacin had a sensitive SERS signal at 806 cm^-1. The enhancement factor (EF) was 2.11 × 10⁷. There was a good linear correlation between the concentration of marbofloxacin and SERS intensity: the linear range was 0.003-0.03 μmol L^-1 (r² = 0.996). The limit of detection (LOD) (S/N = 3) was 1.7 nmol L^-1 (S/N = 3). Moreover, the influence of some interferences including Cu²⁺, K⁺, Zn²⁺, Ca²⁺, Na⁺, Mg²⁺, glucose and tiamulin on the determination were studied. The developed SERS method was used to detect the content of marbofloxacin in chicken and duck, the recovery was 101.3%-103.1% with RSD 4.07%-6.83%.

Effect of supportive therapy on the pharmacokinetics of intravenous marbofloxacin in endotoxemic sheep

The purpose of this study was to determine the influences of supportive therapy (ST) on the pharmacokinetics (PK) of marbofloxacin in lipopolysaccharide (LPS)-induced endotoxemic sheep. Furthermore, minimum inhibitory concentration (MIC) of marbofloxacin against Escherichia coli, Mannheimia haemolytica, Pasteurella multocida, Klebsiella pneumoniae, Salmonella spp., and Staphylococcus aureus was determined. The study was performed using a three-period cross PK design following a 15-day washout period. In the first period, marbofloxacin (10 mg/kg) was administered by an intravenous (IV) injection. In the second and third periods, marbofloxacin was co-administered with ST (lactated ringer + 5% dextrose + 0.45% sodium chloride, IV, 20 ml/kg, dexamethasone 0.5 mg/kg, SC) and ST + LPS (E. coli O55:B5, 10 µg/kg), respectively. Plasma marbofloxacin concentration was measured using HPLC-UV. Following IV administration of marbofloxacin alone, the t 1 / 2 λ z , AUC_0-∞ , Cl_T , and V_dss were 2.87 hr, 34.73 hr × µg/ml, 0.29 L hr^-1  kg^-1 , and 0.87 L/kg, respectively. While no change was found in the MBX + ST group in terms of the PK parameters of marbofloxacin, it was determined that the Cl_T of marbofloxacin decreased, AUC_0-∞ increased, and t 1 / 2 λ z and MRT prolonged in the MBX + ST + LPS group. MIC values of marbofloxacin were 0.031 to >16 µg/ml for E. coli, 0.016 to >16 µg/ml for M. haemolytica, 0.016-1 µg/ml for P. multocida, 0.016-0.25 µg/ml for K. pneumoniae, 0.031-0.063 µg/ml for Salmonella spp., and 0.031-1 µg/ml for S. aureus. The study results show the necessity to make a dose adjustment of marbofloxacin following concomitant administration of ST in endotoxemic sheep. Also, the PK and pharmacodynamic effect of marbofloxacin needs to be determined in naturally infected septicemic sheep following concomitant administration of single and ST.