Eltrombopag, a thrombopoietin receptor agonist, is used for the treatment of idiopathic thrombocytopenic purpura (ITP) and aplastic anemia. We developed a HPLC assay for the determination of serum eltrombopag concentration in ITP patients. An aliquot of a serum sample spiked with diclofenac as the internal standard (IS) was treated with acetonitrile to precipitate the proteins. Eltrombopag and the IS were separated on an octadecylsilyl silica‐gel column using a mobile phase consisting of 10 mM 1‐pentanesulfonic acid sodium salt, acetonitrile, and acetic acid. The detection wavelength was set at 265 nm. The calibration curve was linear at the concentration range of 0.15–12.5 μg/mL for eltrombopag (r = 0.9987). The recoveries of eltrombopag from the serum samples were greater than 95.9% with coefficients of variation (CVs) being less than 2.8%. The CVs for the intra‐day and inter‐day assays were 1.9–11.8% and 1.0–11.8%, respectively. This assay method could be used for therapeutic drug monitoring of eltrombopag in ITP patients.

中文翻译：

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一种简单的HPLC测定人血清中Eltrombopag浓度的方法

血小板生成素受体激动剂Eltrombopag用于治疗特发性血小板减少性紫癜（ITP）和再生障碍性贫血。我们开发了用于测定ITP患者血清Eltrombopag浓度的HPLC测定法。将加有双氯芬酸作为内标（IS）的血清样品的等分试样用乙腈处理，以沉淀蛋白质。Eltrombopag和IS在十八烷基甲硅烷基硅胶柱上分离，流动相由10 mM 1-戊烷磺酸钠盐，乙腈和乙酸组成。检测波长设定为265nm。Eltrombopag的校正曲线在0.15–12.5μg/ mL的浓度范围内是线性的（r = 0.9987）。血清样品中Eltrombopag的回收率大于95.9％，变异系数（CV）小于2.8％。日内和日间分析的CV分别为1.9-11.8％和1.0-11.8％。该测定方法可用于ITP患者的Eltrombopag的治疗性药物监测。