Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, Anand Agricultural University, Anand-388001, Gujarat State, India
Pharmacokinetics of ceftriaxone was studied in buffalo calves (Bubalus bubalis) after single intravenous and intramuscular administration of 10 mg/kg body weight. The drug concentrations in plasma samples were measured by high performance liquid chromatography with UV detection. Following intravenous administration, the drug was rapidly distributed (Cpo: 106.5 ± 9.64 μg/ml; t1/2α: 0.09 ± 0.01 h; Vdarea: 0.48 ± 0.05 L/kg) and eliminated (t1/2β: 1.27 ± 0.04 h) from the body with a clearance rate of 4.40 ± 0.44 ml/min.kg. Following intramuscular administration, the peak plasma concentration of the drug was 15.8 ± 2.4 μg/ml at 0.5 h and the drug was detected up to 12 h. The drug was rapidly absorbed from the site of injection (t1/2ka: 0.35 ± 0.01 h), widely distributed (Vdarea: 1.53 ± 0.2 L/kg) and slowly eliminated from the body (t1/2β: 4.38 ± 0.4 h; ClB: 4.01 ± 0.30 ml/min.kg). The bioavailability of ceftriaxone was 70.2 ± 2.0% following intramuscular injection. Intramuscular injection of ceftriaxone has favourable pharmacokinetics and moderate bioavailability in buffalo calves and can be used for susceptible infections in calves.