The bioequivalence determination of two different formulations of enrofloxacin in heifers following intramuscular administration.

th , 60 th and 90 th min. and 2 th , 3 th , 4 th , 6 th , 8 th , 12 th and 24 th h following injections. The plasma concentrations of enrofloxacin (ENR) were measured by high performance liquid chromatography (HPLC) following the extraction process. The plasma concentration-time curves for each animals showed that both products distributed according two-compartment open model. The basic pharmacokinetic parameters at this study were only the AUC 0-24 and AUC total were statistically significant (P<0.05) before logarithmic (log) transformation. Log transformed the AUC 0-24, AUC tota l and C max parameters and observed t max were used in BE evaluation. Minimum, maximum and mean AUC 0-24 AUC tota l and C max for A and B products were found in the acceptable ranges (70-143%). For the t max value log transformation has not been done and that were determined within the limits 80-125%. As a result; it is concluded that both products could be used instead of each other as an "inter-changeable drugs".