Pharmacokinetics of Norfloxacin in Control Healthy and E. coli Infected Lactating Goats

The pharmacokinetics of norfloxacin was studied following repeated intramuscular injections in normal and experimentally infected goats. The serum concentrations of norfloxacin following repeated intramuscular injections of 10 mg/kg.b.wt. once daily for five consecutive days, peaked 4 hours after each intramuscular dose with lower significant values recorded in experimentally infected goats than in normal ones. Urine and milk concentrations of norfloxacin were decreased significantly in infected than in normal goats following repeated intramuscular injections. Following a single intravenous injection of norfloxacin in normal goats, serum concentration-time curve was best described by a two compartments open model with elimination half life (t0.5(β)=5.96 h), volume of distribution (Vd=0.42 L/kg) and total clearance of the drug (CLtot=0.18 ml/kg/min). The mean systemic bioavailability of norfloxacin following intramuscular injection in normal goats was 70.04%. The extent of serum protein binding of norfloxacin in goats was 14.07%. Following intramuscular injection of 10 mg/kg.b.wt of norfloxacin for 5 consecutive days, norfloxacin showed a cumulative behaviour in serum, urine and milk of goats. Results of this study indicated that norfloxacin was useful for treatment of urinary tract infections and mastitis in goats.