Pharmacokinetics of ivermectin following single dose subcutaneous administration in cattle calves

The present study was undertaken to evaluate the pharmacokinetics of ivermectin 0.2 mg/kg b.wt in cattle calves. The study was conducted in four cross-bred male cattle calves (1.0-1.5 yrs in age, weighing 110±5 kg). The plasma concentration of ivermectin was determined by HPLC. The decay in plasma concentration of drug was biexponential in cattle calves. The C_max value of 32.31 was obtained at T_max of 4.4 days in cattle calves, following SC administration of ivermectin. The elimination half life (β_HL), volume of distribution (V1_F) and AUC were calculated as 24.59 days, 2.28 L.kg^-1, 393.9 day.ng/mL in cattle calves, following SC administration of ivermectin. A dosage regimen of 0.2 mg/kg at 14 days interval is recommended in cattle.