IVERMECTIN IN GOAT PLASMA AND MILK AFTER SUBCUTANEOUS INJECTION

The pharmacokinetics and mammary excretion of ivermectin were determin ed in goats following a single sc administration (0.2 mg/kg). Kinetic analysis of plasma and milk levels was performed using a 1-compartment model. The maximum plasma concentration of 6.12 ng/ml occurred at 2.8 5 d ; the half-life of 4.03 d was similar to the value in sheep (3.68 d). Ivermectin was detected in the milk at the first sampling time and thereafter for at least 25 d. Comparison of the milk and plasma data shows the parallel disposition of the drug in milk and plasma with a m ilk-plasma concentration ratio of 1.08 +/- 0.23. In conclusion, the pe rsistence of the drug in plasma is refLected in the duration of the pr esence of ivermectin in milk.