Background: Atopic dermatitis (AD) is an allergic skin disease that can be inherited. Crisaborole is a specific drug developed to deal with this disease. The compounds of 4-(4- Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4-bromo-3-formylphenoxy)-3- formylphenoxy) benzonitrile are the representative impurities in the synthesis of Crisaborole active pharmaceutical in gradient (API). Owing to the genotoxic impurities that could lead to cancer and gene mutations, it is necessary to develop a simple, efficient, sensitive, and accurate method to detect these impurities. In this study, the 4-(4-Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4- bromo-3-formylphenoxy)-3-formylphenoxy)benzo- nitrile present in Crisaborole API were detected using UPLC-MS/MS. Methods: The separation was made on a ZORBAX Eclipse XDB-Pheny column (4.6 mm ×75mm, 3.5 μm) with the mobile phase of acetonitrile solution containing 0.1% trifluoroacetic acid (A) and water containing 0.1% formic acid (B) in gradient elution mode. Quantification was performed using positive ion electrospray ionization (ESI), and the contents of two compounds were determined using the multiple reaction monitoring (MRM) modes. Results: The quantitative analytical method was fully validated with respect to linearity (r > 0.9998), sensitivity, precision, accuracy (the average recovery of two impurities was 84.1% to 90.7%), and robustness. Conclusion: Three batches of samples were detected by UPLC-MS/MS, indicating that the proposed approach was applicable for the quality evaluation of Crisaborole.

中文翻译：

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采用 UPLC-MS/MS 测定 Crisaborole API 中的两种潜在基因毒性杂质

背景：特应性皮炎（AD）是一种可以遗传的过敏性皮肤病。Crisaborole 是一种专门为治疗这种疾病而开发的药物。4-(4-溴-3-甲酰基-苯氧基)-苯甲腈和4-(4-(4-溴-3-甲酰基苯氧基)-3-甲酰基苯氧基)苯甲腈化合物是Crisaborole活性药物合成中的代表性杂质梯度（API）。由于基因毒性杂质可能导致癌症和基因突变，因此有必要开发一种简单、高效、灵敏、准确的方法来检测这些杂质。在本研究中，使用 Crisaborole API 检测到 4-(4-溴-3-甲酰基-苯氧基)-苯甲腈和 4-(4-(4-溴-3-甲酰基苯氧基)-3-甲酰基苯氧基)苯甲腈UPLC-MS/MS。方法：在 ZORBAX Eclipse XDB-Pheny 色谱柱（4.6 mm × 75mm，3. 5 μm)，流动相为含0.1%三氟乙酸的乙腈溶液(A)和含0.1%甲酸的水(B)，梯度洗脱。使用正离子电喷雾电离（ESI）进行定量，并使用多反应监测（MRM）模式测定两种化合物的含量。结果：定量分析方法在线性（r > 0.9998）、灵敏度、精密度、准确度（两种杂质平均回收率为84.1%~90.7%）、稳健性方面得到充分验证。结论：UPLC-MS/MS对3批样品进行了检测，表明该方法适用于Crisaborole的质量评价。1% 甲酸 (B)，梯度洗脱模式。使用正离子电喷雾电离（ESI）进行定量，并使用多反应监测（MRM）模式测定两种化合物的含量。结果：定量分析方法在线性（r > 0.9998）、灵敏度、精密度、准确度（两种杂质平均回收率为84.1%~90.7%）、稳健性方面得到充分验证。结论：UPLC-MS/MS对3批样品进行了检测，表明该方法适用于Crisaborole的质量评价。1% 甲酸 (B)，梯度洗脱模式。使用正离子电喷雾电离（ESI）进行定量，并使用多反应监测（MRM）模式测定两种化合物的含量。结果：定量分析方法在线性（r > 0.9998）、灵敏度、精密度、准确度（两种杂质平均回收率为84.1%~90.7%）、稳健性方面得到充分验证。结论：UPLC-MS/MS对3批样品进行了检测，表明该方法适用于Crisaborole的质量评价。该定量分析方法在线性（r > 0.9998）、灵敏度、精密度、准确度（两种杂质的平均回收率为84.1%~90.7%）和稳健性方面得到了充分验证。结论：UPLC-MS/MS对3批样品进行了检测，表明该方法适用于Crisaborole的质量评价。该定量分析方法在线性（r > 0.9998）、灵敏度、精密度、准确度（两种杂质的平均回收率为84.1%~90.7%）和稳健性方面得到了充分验证。结论：UPLC-MS/MS对3批样品进行了检测，表明该方法适用于Crisaborole的质量评价。