Plasma Disposition Kinetics, Erythrocytic Penetration and Dosage Regimen of Diacetylmonoxime in Cross-Bred Calves Following Intramuscular Administration

The ptasma disposition kinetics, erythrocytic penetration and dosage regimen of diacetylmonoxime (DAM) were investigated in cross-bed cow calves after a single intramuscular administration (30mg/kg). At 1min following administration, the plasma concentration was 23.9±0.58 µg/ml, which rose to 70.3±0.49 µg/ml at 15 min. The drug was detected upto 24h (1.4 ±1.3 µg.ml-1) and the minimum therapeutic plasma concentration (≥ 4µg.ml⁻¹) was maintained upto 12h. The disposition pattern was determined by one compartment open model. The t_½^ka and t_½^β were found to be 0.16 ± 0.10 h and 5.76 ± 0.32 h, respectively. The V_d(area), CI_B and AUC were calculated to be 1.05±0.09 L.kg⁻¹, 124.8 ± 14.9 ml.kg⁻¹ h⁻¹ and 319.4± 10.1µg.ml⁻¹ x h, respectively. At different blood concentrations, DAM penetrated into erythrocytes to the extent of 29.8 ± 0.67 percent of total blood concentration. Based on above disposition kinetic data, a satisfactory intramuscular dosage regimen of DAM in cow calves was calculated to be 18 mg/kg followed by 14mg/kg at 12h intervals.