Division of Clinical Pharmacology & Toxicology, Department of Biomedicine, University and University Hospital Basel, Switzerland.
Division of Clinical Pharmacology & Toxicology, Department of Biomedicine, University and University Hospital Basel, Switzerland.
J Pharm Biomed Anal. 2019 Aug 5;172:18-25. doi: 10.1016/j.jpba.2019.04.007. Epub 2019 Apr 16.
Ivermectin is deployed in mass drug administration (MDA) campaigns to control parasitic diseases in the tropics, with billions of treatments having been administered in the last three decades. Simple blood sampling tools, like the dried blood spots (DBS) technique, are needed to monitor treatments in such challenging settings. Thus, we developed a fully automated method for the analysis of ivermectin in DBS microsamples, including a bioanalytical and clinical validation. Automated extraction was carried out using a DBS-MS 500 autosampler which was coupled to a LC-MS/MS system. DBS were extracted with 20 μL solvent and eluted on a C8 analytical column. Analysis was performed by multiple reaction monitoring in the positive mode. Automated DBS extraction resulted in consistent recoveries (62.8 ± 4.3%) and matrix effects (68.0 ± 8.1%) between different donors and concentration levels. Intra- and inter-day accuracy and precision deviations were ≤15%, while samples with hematocrits from 20 to 60% could be quantified reliably. The achieved sensitivity of 1 ng/mL in DBS samples is sufficient to analyze ivermectin at the dose given (single oral administration of 12 mg) over a period of at least 72 h post treatment. Importantly, DBS samples are stable after one-month storage at room temperature (accuracy: 88.8-96.2%), thus samples collected in the field must not be shipped on dry ice. Ivermectin concentrations in venous and capillary blood agreed strongly, with a mean difference of -4.8%. Moreover, the drying process of DBS did not alter the analysis and importantly plasma concentrations can be estimated from DBS data using the hematocrit and red blood cell partitioning as correction factor. Our method enables uncomplicated sample collection and shipment as well as automated analysis of large amounts of samples, which is key to surveying MDA campaigns in remote settings.
伊维菌素被用于大规模药物治疗（MDA）活动中，以控制热带地区的寄生虫病，在过去三十年中已经进行了数十亿次治疗。在这种具有挑战性的环境中，需要简单的血液采样工具，如干血斑（DBS）技术，来监测治疗效果。因此，我们开发了一种全自动分析 DBS 微样本中伊维菌素的方法，包括生物分析和临床验证。使用 DBS-MS 500 自动进样器进行自动提取，该自动进样器与 LC-MS/MS 系统相连。DBS 用 20μL 溶剂提取，在 C8 分析柱上洗脱。分析采用正模式下的多重反应监测。自动 DBS 提取可获得一致的回收率（62.8±4.3%）和基质效应（68.0±8.1%），不受不同供体和浓度水平的影响。日内和日间准确度和精密度偏差均≤15%，而红细胞压积为 20-60%的样品也可可靠定量。DBS 样品中达到的 1ng/mL 灵敏度足以分析治疗后至少 72 小时内单次口服 12mg 伊维菌素的剂量。重要的是，DBS 样品在室温下储存一个月后仍稳定（准确度：88.8-96.2%），因此野外采集的样品不必用干冰运输。静脉血和毛细血管血中的伊维菌素浓度具有很强的一致性，平均差异为-4.8%。此外，DBS 的干燥过程不会改变分析结果，重要的是，血浆浓度可以使用红细胞压积和红细胞分配作为校正因子，从 DBS 数据中估算出来。我们的方法能够方便地进行样品采集和运输，以及对大量样品进行自动化分析，这对于偏远地区 MDA 活动的调查至关重要。
