Impact of ivermectin and triclabendazole residues on milk processing

IEZZI, S.; IMPERIALE, F.; FARIAS, C.; LIFSCHITZ, A.; SALLOVITZ, J.; LANUSSE, C.

Rosario

Congreso; XLI Reunión anual de la Asociación Argentina de Farmacología Experimental; 2009

Soc. Argentina de Farmacologia Experimental

Ivermectin (IVM) is a broad-spectrum antiparasitic macrocyclic lactone (ML) extensively used in food-producing animals. Triclabendazole (TCBZ) is an halogenated benzimidazole (BZD) compound worldwide used to control immature and adult stages of liver fluke (F. hepatica). The patterns of milk residue excretion for different ML and BZD compounds have been recently determined in our laboratory. The current trial addressed the evaluation of the stability of IVM and TCBZ residual concentrations in milk under heating conditions as those reached during milk processing. IVM and TCBZ concentrations were measured in milk using HPLC-based methodology with fluorescence detection for IVM and UV detection for TCBZ. IVM (0.1-20ng/ml) and TCBZ (0.1-20µg/ml) were added to drug-free milk samples collected from untreated lactating cows. Drug-spiked milk samples were heated at 65ºC for 30 minutes (pasteurization). IVM and TCBZ concentrations were measured prior and after the heating process. Results obtained indicate that no significant changes in the IVM and TCBZ residue profiles take place after heating. Variation observed in residual concentrations in heated milk was within the range of the analytical method. The “yoghurt test” was used to determining any inhibition effect of IVM and TCBZ residues on lactic bacteria. Concentrations studied caused no bacterial inhibition. The impact of these residual drugs conecntrations in milk-derived product on human safety and industrial processing are under further evaluation.