A micellar electrokinetic capillary chromatography (MEKC) method has been developed and validated for simultaneous analysis of febuxostat and its related substances in active pharmaceutical ingredients and pharmaceutical formulations. Analysis was performed in an uncoated fused silica capillary (34 cm effective length, 50 µm diameter). Method sensitivity was enhanced using an extended light path capillary, with an optical path 150 µm and the choice of 320 nm detector operating wavelength due to lower background noise and higher selectivity. BGE consisted of 20 mM borate buffer pH 9.3 and 50 mM SDS and 2% acetonitrile. Analysis was performed at 30 kV separation voltage and 32 °C capillary temperature. The method was linear over the range 1.0–10.0 µg mL−1 for each impurity corresponding to reporting limits regarding the ICH Q3A guidelines. The method has proven to be selective, precise, accurate and robust. Proposed MEKC method has been successfully applied for the quantitative determination of febuxostat and purity assay of active pharmaceutical ingredient and tablet dosage forms.

中文翻译：

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同时测定非布司他及其相关杂质的简便快速胶束电动色谱法

已开发并验证了一种胶束电动毛细管色谱 (MEKC) 方法，用于同时分析活性药物成分和药物制剂中的非布司他及其相关物质。在未涂层的熔融石英毛细管（34 cm 有效长度，50 µm 直径）中进行分析。使用扩展光程毛细管提高了方法灵敏度，光程为 150 µm，并且由于较低的背景噪声和较高的选择性，因此可选择 320 nm 检测器工作波长。BGE 由 20 mM 硼酸盐缓冲液 pH 9.3 和 50 mM SDS 和 2% 乙腈组成。在 30 kV 分离电压和 32 °C 毛细管温度下进行分析。对于每种杂质，该方法在 1.0–10.0 µg mL-1 范围内呈线性，与 ICH Q3A 指南的报告限值相对应。该方法已被证明具有选择性、精确性、准确度和稳健性。提出的 MEKC 方法已成功应用于非布司他的定量测定和活性药物成分和片剂剂型的纯度测定。