A Robust Stability‐Indicating RP‐HPLC Method for Quantification of Topiroxostat and Dotinurad: Method Development, Validation, and Degradation Studies

The investigation developed a new stability-indicating reverse-phase high-pressure liquid chromatographic (RP-HPLC) assay method to quantify Topiroxostat and Dotinurad in pharmaceutical dosage forms. The technique used is isocratic elution on an Inertsil ODS-3 C18 column (150 × 4.6 mm, 5μm particle size) with a mobile phase of buffer (pH 4.0) and acetonitrile (50:50 v/v). The separation was monitored using UV detection at 285 nm. The retention times of Topiroxostat and Dotinurad were about 2.85 and 7.72 min, respectively. Additionally, the linearity of Topiroxostat and Dotinurad was between 4.0-32.0 μg/mL and 0.2-1.6 μg/mL, respectively. The limit of detection and quantitation of Topiroxostat and Dotinurad were 0.0027 and 0.0011 μg/mL, respectively. The method's applicability was validated through the analysis of pharmaceutical dosage forms, demonstrating its suitability for routine quality control in pharmaceutical laboratories. Analytical performance parameters were determined in accordance with ICH guidelines, ensuring the method's reliability. The method was simple, precise, accurate, robust, and rapid, making it suitable for quantifying Topiroxostat and Dotinurad in pharmaceutical products.