Pattern of ivermectin (sheep) and doramectin (cattle) residues in muscular tissue from different anatomical locations

MORENO, L.; ALVAREZ, L.; CEBALLOS, L.; SANCHEZ BRUNI, S.; LANUSSE, C.

FOOD ADDITIVES AND CONTAMINANTS

TAYLOR & FRANCIS LTD

Año: 2008 vol. 25 p. 406 - 412

0265-203X

The trial reported here characterized the comparative drug residual concentrations in muscular tissue obtained from different anatomical locations after subcutaneous administration of ivermectin (IVM) to sheep and topical treatment with doramectin (DRM) to calves at recommended therapeutic dose rates. Seven muscle samples from different anatomical locations (Rhomboideus, Supraspinatus, Semitendinosus, Gluteus medius, Longissimus dorsi thoracis, Intercostales and Diaphragma) were collected at several post-treatment sampling times. Samples were frozen at –20 ºC until analyzed by high performance liquid chromatography (HPLC). The highest IVM residual concentrations in muscular tissue from the different locations were found at 15 days post-treatment in sheep. Although the highest IVM mean concentrations were measured at 15 (16.8 ± 5.17 ng g-1) and 20 (10.5 ± 4.06 ng g-1) days post-administration in the Intercostales muscles, at 30 days post-administration the IVM concentration in this location was similar to that measured in the Rhomboideus and Diaphragma muscles. DRM residual concentrations were quantified in muscular tissue from all the anatomical locations after topical administration to calves. The maximum residue level was observed at 10 days post-treatment in all the anatomical sites. The Diaphragma  muscle showed the highest DRM residue levels at 2 (22.0 ± 4.35 ng g-1), 5 (45.2 ± 3.78 ng g-1) and 10 (57.9 ± 9.57 ng g-1) days post-treatment in calves. These results demonstrated that the pattern of residues depletion from muscular tissue may differ according to its anatomical locations and/or physiological role. This should be considered when residue control strategies are implemented to assure meat safety for human consumption.