In our research, a straightforward UPLC-MS/MS method, with diazepam as the internal standard (IS), was proposed and acknowledged to determine the concentrations of enasidenib in rat plasma. When preparing the sample, we used acetonitrile for protein precipitation. The gradient elution method was used, and the mobile phase was acetonitrile and 0.1% formic acid. Diazepam was used as the IS. We used the Acquity UPLC BEH C18 column to separate enasidenib and IS. Under the positive ion electrospray ionization (ESI) source conditions, the mass transfer pairs of enasidenib were monitored by multiple reaction monitoring (MRM) to be m/z 474.2 ⟶ 456.1 and m/z 474.2 ⟶ 267.0, and the IS mass transfer pairs were m/z 285.0 ⟶ 154.0. Enasidenib had good linearity (r² = 0.9985) in the concentration range of 1.0–1000 ng/mL. Besides, the values of intraday and interday precision were 2.25–8.40% and 3.94–5.46%, respectively, and the range of the accuracy values varied from −1.44 to 2.34%. Matrix effect, extraction recovery, and stability were compliant with FDA approval guidelines in terms of bioanalytical method validation. We had established a new method that had been applied to the pharmacokinetic study of enasidenib in rats.

中文翻译：

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UPLC-MS / MS法测定恩西地尼在大鼠血浆中的建立和验证及其药代动力学应用。

在我们的研究中，提出了一种以地西epa为内标（IS）的简便的UPLC-MS / MS方法，并被确认用于测定大鼠血浆中依那西尼的浓度。在制备样品时，我们使用乙腈进行蛋白质沉淀。使用梯度洗脱方法，流动相为乙腈和0.1％甲酸。地西p被用作IS。我们使用Acquity UPLC BEH C18色谱柱分离了依那替尼和IS。在正离子电喷雾电离（ESI）源条件下，通过多反应监测（MRM）将依那西德的传质对监测为m / z 474.2⟶456.1和m / z 474.2⟶267.0，而IS传质对为m / z 285.0×154.0。Enasidenib具有良好的线性（r ²  = 0.9985），浓度范围为1.0–1000 ng / mL。此外，日内和日间精度值分别为2.25–8.40％和3.94–5.46％，精度值的范围从−1.44至2.34％。在生物分析方法验证方面，基质效应，提取回收率和稳定性均符合FDA批准指南。我们建立了一种新的方法，该方法已被用于大鼠依那替尼的药代动力学研究。