We compared the pharmacokinetics of ivermectin premix and ivermectin microspheres in pigs after single and multiple administration regimes. In the single‐dose experiments, 24 piglets were randomly divided into three groups and given ivermectin at 0.3 mg/kg using (a) 1.0% ivermectin administered subcutaneously, (b) 0.25% ivermectin premix orally, and (c) 0.25% ivermectin microspheres orally. In the multiple‐dose experiment, 6 pigs in two equal groups received ivermectin premix and microspheres orally at 0.3 mg/kg for 7 consecutive days to monitor the valley plasma levels. The plasma samples were detected by fluorescence high‐performance liquid chromatography, and concentration–time data were fitted to a noncompartmental model. After oral administration of ivermectin microspheres at a single dose, the elimination rate constant (Kel), the half‐life (t_1/2), the peak time (T_max), the mean residence time (MRT), and the peak concentration (C_max) were 0.012 ± 0.0031/hr, 59.94 ± 20.18 hr, 9.50 ± 0.93 hr, 55.96 ± 11.40 hr, and 37.75 ± 3.45 ng/ml, respectively. The C_max of microspheres was not statistically different (p > .05) compared with that of premix groups (39.81 ± 5.83 ng/ml). Moreover, the AUC of the microcapsule groups was increased from 1,129.76 ± 245.62 to 1,607.33 ± 343.35 hr ng/ml compared with the premix groups, and the relative bioavailability increased by an average of 17.53% after oral administration with ivermectin microspheres. Multiple‐dose administration also indicated pigs fed with ivermectin microspheres can get a higher minimum steady‐state concentration and a longer maintenance time than ivermectin premix.

中文翻译：

---

口服给予伊维菌素微球对健康猪的药代动力学。

我们比较了单次和多次给药后伊维菌素预混物和伊维菌素微球在猪体内的药代动力学。在单剂量实验中，将24只仔猪随机分为三组，并使用（a）皮下注射1.0％伊维菌素，（b）口服0.25％伊维菌素预混液和（c）0.25％伊维菌素微球给予伊维菌素0.3 mg / kg口头。在多剂量实验中，将两组相等的6头猪连续7天口服伊维菌素预混物和微球，剂量为0.3 mg / kg，以监测谷底血浆水平。用荧光高效液相色谱法检测血浆样品，并将浓度-时间数据拟合到非房室模型中。单次口服伊维菌素微球后，消除率常数（Kel），半衰期（t_1/2），峰时间（T _max），平均停留时间（MRT）和峰浓度（C _max）为0.012±0.0031 / hr，59.94±20.18 hr，9.50±0.93 hr，55.96±11.40 hr和分别为37.75±3.45 ng / ml。微球的C _max没有统计学差异（p> .05）与预混组（39.81±5.83 ng / ml）进行比较。此外，与预混物组相比，微胶囊组的AUC从1,129.76±245.62增加到1,607.33±343.35hr ng / ml，相对的生物利用度在口服伊维菌素微球后平均提高了17.53％。多剂量给药还表明，与伊维菌素预混料相比，饲喂伊维菌素微球的猪可以获得更高的最低稳态浓度和更长的维持时间。