Serum bactericidal activity and disposition kinetics of enrofloxacin in Korean native goats

한국재래산양에서 Enrofloxacin의 혈청내 항균효과와 체내동태

Enrofloxacin is one of the second-generation quinolones which have been widely used to treat bacterial infections in various species including chicken, pig, horse and cattle. The objective of the present study was to describe the serum bactericidal activity(SBA) of enrofloxacin, its pharmacokinetic behaviors after intramuscular or intravenous administration to Korean native goats in the dose rate of 5mg/kg b.w. The results obtained through this study were as follows : 1. Sera collected from both sexes of Korean native goats administered 5mg/kg i.v. or i.m. showed potent antibacterial activities up to the 12 hours by way of the serum bactericidal activity. 2. Concentrations of enrofloxacin in the biological samples were measured by high-performance liquid chromatography(HPLC) so as to study pharmacokinetic characteristics. For detection of enrofloxacin, 10% TCA was optimal for protein precipitation and the mobile phase was 0.01M citric acid/methanol/acetonitrile(7/2/1, pH 3.5) with solid phase being the $C_{18}$ reversephase column and detection wavelength being 278nm. The limit of detection of enrofloxacin on HPLC was $0.05{\mu}g/ml$. 3. Pharmacokinetic profile of enrofloxacin administered 5mg/kg i.v. in Korean native goats was best described by two-compartment open model and that administered i.m. the same rate by one-compartment model. There were no sex differences in pharmacokineticl parameters. In conclusion, enrofloxacin showed potent in vivo antibacterial activity and excellent pharmacokinetic properties in Korean native goats, hence it may be used as a potential antibacterial in the veterinary clinical settings.