Moxidectin is a promising candidate for addition to the lean repertoire of drugs against neglected tropical diseases (NTD) including strongyloidiasis. Pharmacokinetic (PK) and -dynamic studies are required to support its clinical development. Microsampling approaches enable PK studies in the challenging environments where NTDs are most prevalent, due to simplified collection and processing.

We developed a liquid chromatography tandem mass spectrometry method for the sensitive quantification of moxidectin in human blood obtained by capillary sampling with the microsampling device Mitra® compared to blood and plasma obtained by venous sampling. Sample preparation consisted of protein precipitation, evaporation and reconstitution and also included phospholipid filtration for blood and plasma. Moxidectin was detected by multiple reaction monitoring (640.4 → 528.5 m/z) using a Luna C8(2) (30 × 2.0 mm, 3 µm particle size, 100 Å) analytical column with a gradient program of 6 min duration. Validation was performed with respect to accuracy, precision, sensitivity, selectivity, linearity, stability, recovery, and haematocrit influence with a limit of quantification of 0.5 and 2.5 ng/mL, for venous and capillary blood respectively. Moxidectin was stable up to 2 months at storage condition (blood and plasma: −20 °C, microsamples: room temperature), 3 cycles of temperature shift, for at least 4 h on the bench-top and 24 h in the autosampler (4 °C). Deviations of inter- and intra-assay accuracy and precision were smaller than 12.6% and recoveries were in the range of 80.7–111.2%.

The method was applied to samples obtained from nine Strongyloides stercoralis-infected adults from northern Laos. A good agreement in the time-concentration profiles of moxidectin and a high consistency in PK parameters was found between the different matrixes and sampling strategies: e.g. identical time to reach maximal concentration of 4.0 h and a similar maximal concentration of 83.9–88.5 ng/mL of moxidectin.

The simple and practical capillary procedure using Mitra® microsampling has been demonstrated to be suitable for PK studies of moxidectin and will pave the way for future PK studies.

莫昔克丁是用于抵抗包括强线虫病在内的被忽视的热带病（NTD）药物的瘦肉库中的有前途的候选药物。需要药代动力学（PK）和动力学研究来支持其临床发展。由于简化了采集和处理，微采样方法可以在NTD最普遍的具有挑战性的环境中进行PK研究。

我们开发了一种液相色谱串联质谱法，与通过静脉采样获得的血液和血浆相比，通过微量采样设备Mitra®通过毛细管采样获得的人血中莫昔克丁的灵敏定量。样品制备包括蛋白质沉淀，蒸发和重构，还包括用于血液和血浆的磷脂过滤。通过多反应监测（640.4→528.5  m / z）使用Luna C8（2）（30×2.0 mm，粒径3 µm，100Å）分析柱，梯度程序为6分钟。分别对静脉血和毛细管血的准确性，精密度，灵敏度，选择性，线性，稳定性，回收率和血细胞比容影响进行了验证，定量限分别为0.5和2.5 ng / mL。莫昔克丁在储存条件下（血液和血浆：-20°C，微量样品：室温），3个温度变化循环在台式条件下至少稳定4h，在自动进样器中稳定24h，可稳定长达2个月（4 °C）。批间和批内准确性和精密度的偏差小于12.6％，回收率在80.7-111.2％的范围内。

该方法应用于从老挝北部感染了9株类固醇的成年人中获得的样本。在不同基质和采样策略之间，莫昔克丁的时间浓度曲线和PK参数具有高度一致性：例如达到最大浓度4.0 h的相同时间和相似的​​最大浓度83.9–88.5 ng / mL的时间莫昔克丁。

已证明使用Mitra®微量采样的简单实用的毛细管程序适用于莫昔克丁的PK研究，并将为将来的PK研究铺平道路。