Thermal stability of antiparasitic macrocyclic lactones milk residues during industrial processing

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

FOOD ADDITIVES AND CONTAMINANTS

Taylor & Francis

Lugar: London; Año: 2009 vol. 26 p. 57 - 62

0265-203X

The chemical stability of milk residues of different antiparasitic macrocyclic lactone compounds subjected to thermal treatment was assessed. Sheep milk residual concentrations of ivermectin (IVM), moxidectin (MXD) and eprinomectin (EPM) equivalent to those measured in vivo in milk excretion studies were subjected to 65ºC over 30 min or to 75ºC during 15 s. Residual IVM, MXD and EPM milk concentrations were measured by HPLC (fluorescence detection) before and after heat treatment of the drug-fortified milk samples. No evidence of chemical loss was obtained in either of the thermal treatments under evaluation. The stability of the parent compounds in milk was evidenced by the lack of bioconversion products (metabolites) after both thermal treatments. Only very minor changes on drug concentrations were observed at the end of the assays, which fell within the limits of the variation of the validated analytical method. In conclusion, residual concentrations of macrocyclic lactones are unaffected by industrialization-related milk thermal procedures. Based on the findings reported here, it can be postulated that residual concentrations of IVM, MXD and EPM measured in raw sheep milk, may be used to estimate consumer exposure and dietary intake for these veterinary drugs.