Ivermectin (IVM) is one of the most widely used antiparasitic drugs worldwide and has become the drug of choice for anthelmintic and tick treatment in beef cattle production. It is known that pharmacokinetic parameters are fundamental to the rational use of a drug and food safety and these parameters are influenced by different factors. The aim of this study was to evaluate the pharmacokinetic profile of IVM in Bos indicus, Bos taurus, and crossbreed cattle (B. indicus × B. taurus) kept under same field conditions and the possible impacts of sex and IVM formulation (1% and 3.15%). It was observed that IVM concentration was significantly affected by breed. The plasma concentrations of IVM, AUC, C_max, and t_1/2β were significantly higher in B. indicus compared to B. taurus. Crossbreed animals showed an intermediate profile between European and Indian cattle. No alteration in pharmacokinetics parameters was detected when comparing different gender. Concerning the pharmacokinetic data of IVM formulation, it was verified that T_max, AUC, and t_1/2β were higher in 3.15% IVM animals than those from 1% IVM formulation. The results clearly indicated that the IVM plasma concentrations in B. indicus were higher than that in B. taurus.

中文翻译：

---

品种，性别和药物浓度对伊维菌素在牛体内药代动力学特征的影响。

伊维菌素（IVM）是全球使用最广泛的抗寄生虫药物之一，已成为肉牛生产中驱虫和tick虫治疗的首选药物。众所周知，药代动力学参数对于合理使用药物和食品安全至关重要，而这些参数受不同因素的影响。这项研究的目的是评估在相同田间条件下饲养的Bos indicus，Bos taurus和杂交牛（B. indicus  ×  B. taurus）中IVM的药代动力学特征，以及性别和IVM配方的可能影响（1％和3.15％）。观察到IVM浓度受品种显着影响。IVM，AUC，C _max的血浆浓度和吨_{1 /2β}均显著更高B.蜓相比B.金牛座。杂种动物显示出欧洲和印度牛之间的中间状况。比较不同性别时，未发现药代动力学参数发生变化。关于IVM制剂的药代动力学数据，证实了3.15％IVM动物中的T _max，AUC和t _{1 /2β}高于1％IVM制剂中的动物。结果清楚地表明，印度芥中的IVM血浆浓度高于金牛座中的IVM血浆浓度。