Laboratorio de Farmacologia, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2009 Jan;26(1):57-62. doi: 10.1080/02652030802322879.
The chemical stability of residues of different antiparasitic macrocyclic lactone compounds in milk subjected to thermal treatment was assessed. Concentrations of ivermectin (IVM), moxidectin (MXD) and eprinomectin (EPM) in sheep milk, equivalent to those measured in vivo in milk excretion studies, were subjected to 65 degrees C over 30 min or to 75 degrees C for 15 s. Residue concentrations of IVM, MXD and EPM in milk were measured by high-performance liquid chromatography (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 treatments, which fell within the limits of the variation of the validated analytical method. In conclusion, residue concentrations of macrocyclic lactones are unaffected by industrial-simulated milk thermal procedures. Based on the reported findings, it can be postulated that residue 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.
本研究评估了经热处理后不同抗寄生虫大环内酯类化合物在牛奶中残留的化学稳定性。将绵羊奶中相当于体内药物排泄研究中测量到的伊维菌素（IVM）、莫昔克丁（MXD）和埃普里诺菌素（EPM）浓度，在 65°C 下加热 30 分钟或在 75°C 下加热 15 秒。通过高效液相色谱（HPLC）（荧光检测）在药物强化牛奶样品进行热疗前后测量牛奶中 IVM、MXD 和 EPM 的残留浓度。在评估的两种热处理中，均未发现化学损失的证据。母体化合物在牛奶中的稳定性通过两种热处理后均未发现生物转化产物（代谢物）得到证明。在处理结束时，仅观察到药物浓度有非常小的变化，这些变化在经过验证的分析方法的变化范围内。总之，大环内酯类化合物的残留浓度不受工业模拟牛奶热处理的影响。基于报告的发现，可以假设在生绵羊奶中测量到的 IVM、MXD 和 EPM 的残留浓度可用于估计这些兽药的消费者暴露和膳食摄入量。
