Measurement of drug concentrations in hair provides a non-invasive approach to assess drug adherence. Here, we report on the development and validation of a method for the quantification of the antiretroviral dolutegravir (DTG) extracted from human hair. DTG is extracted from hair samples by sonication and incubation in 50:50 methanol:acetonitrile with 2% formic acid overnight at 40 °C. Following extraction, samples are analyzed by reverse-phase chromatography on a Waters Atlantis T3 (50 × 2.1 mm, 3-μm particle size) column with subsequent detection by electrospray ionization in positive ion mode on an AB Sciex API-5000 triple quadrupole mass spectrometer. The stable, isotopically labeled ¹³C,d₅-DTG is used as an internal standard in the assay. The calibration range is 5–10,000 pg DTG/mL of extraction solvent with the ability to extract between 1 and 10 mg of hair/mL of extraction solvent. The assay was linear, accurate (inter-assay %bias within ± 6.5%), and precise (inter-assay %CV ≤ 10.3%). The assay was successfully used to analyze clinical samples from subjects on DTG regimens. Analysis of clinical samples suggested the potential presence of a degradation product, which was subsequently confirmed to occur with exposure to sunlight. The degradation of DTG could complicate absolute interpretation of clinical results, but the presence of this degradation product is easily evaluated with this assay to aid in data interpretation.

中文翻译：

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LC-MS / MS测定方法的开发和验证，用于定量从人发中提取的dolutegravir

头发中药物浓度的测量提供了一种评估药物依从性的非侵入性方法。在这里，我们报道了从人发中提取的抗逆转录病毒dolutegravir（DTG）定量方法的开发和验证。通过超声处理并在40°C下在含有2％甲酸的50:50甲醇：乙腈中孵育过夜，从头发样品中提取DTG。提取后，样品在Waters Atlantis T3（50×2.1 mm，3-μm粒径）色谱柱上进行反相色谱分析，随后在AB Sciex API-5000三重四极杆质谱仪上以正离子模式通过电喷雾电离检测。同位素标记的稳定¹³ C，d ₅-DTG在测定中用作内标。校准范围是5–10,000 pg DTG / mL萃取溶剂，能够萃取1至10 mg的头发/ mL萃取溶剂。该测定是线性的，准确的（测定间的偏差百分比在±6.5％之内）和精确的（测定间的％CV≤10.3％）。该测定法已成功用于分析来自DTG方案的受试者的临床样品。临床样品分析表明可能存在降解产物，随后证实该降解产物暴露在阳光下会发生。DTG的降解可能会使临床结果的绝对解释复杂化，但是可以通过此测定法轻松评估该降解产物的存在，以帮助进行数据解释。