Pharmacokinetics of cefpirome in buffalo calves (Bubalus bubalis) following single intramuscular administration

The pharmacokinetics of cefpirome was investigated in buffalo calves following its single intramuscular (IM) administration (10 mg). The peak plasma concentration of cefpirome at 30 min was 9.0 ± 0.5 μg.ml-1, which declined to 0.2 ± 0.1 μg.ml -1 at 24 hrs. The absorption half-life (t1/2Ka) and elimination half-life (t1/2 β) were 0.19 ± 0.03 hr and 2.39 ± 0.05 hr, respectively. The area under the plasma concentration-time curve (AUC), area under the first moment curve (AUMC), apparent volume of distribution (Vd area), total body clearance (ClB), mean residence time (MRT) and total duration of therapeutic effect (td) were 28.7 ± 1.9μg.ml-1.hr, 107.7 ± 6.7 μg.ml-1.hr2, 0.42 ± 0.01 L.kg-1, 0.12 ± 0.003 L.kg-1.hr-1, 3.76 ± 0.04 hr and 12.7 ± 0.3 hr, respectively. The systemic bioavailability (F) after IM administration of cefpirome in calves was 35.3 ±3.1%. To maintain a minimum therapeutic concentration of 0.25 μg.ml-1, a satisfactory dosage regimen of cefpirome in buffalo calves was 3.46 mg.kg-1 followed by 3.36 mg.kg-1  at 12-hour intervals. Cefpirome was bound to the plasma proteins of buffalo calves in vitro  to the extent of 30.7 ± 1.9%