University of Alexandria, Faculty of Pharmacy, Pharmaceutical Chemistry Department, Elmessalah, Alexandria 21521, Egypt.
Pharco Pharmaceuticals Company, Methodology Department, Alexandria, Egypt.
J AOAC Int. 2023 Jul 17;106(4):854-865. doi: 10.1093/jaoacint/qsad028.
Careful review of the scientific databases revealed that no stability-indicating analytical method is available for the binary mixture of allopurinol (ALO) and thioctic acid (THA).
A comprehensive stability-indicating HPLC-DAD procedure has been executed for concurrent analysis of ALO and THA.
Successful chromatographic separation of the cited drugs was reached using a Durashell C18 column (4.6 × 250 mm, 5 µm particle size). The mobile phase consisted of a mixture of acidified water (pH 4.0) using phosphoric acid and acetonitrile pumped in gradient elution mode. For quantification of ALO and THA, their respective peak areas were recorded at 249 and 210 nm. A systematic validation of analytical performance was investigated in terms of system suitability, linearity, ranges, precision, accuracy, specificity, robustness, detection, and quantification limits.
ALO and THA peaks emerged at retention times 4.26 and 8.15 min, respectively. Linear ranges for ALO and THA were 5-100 and 10-400 µg/mL, respectively, with correlation coefficient values exceeding 0.9999. Both drugs were exposed to conditions of neutral, acidic, and alkaline hydrolysis, oxidation, and thermal decomposition. Stability-indicating features have been demonstrated by resolution of the drugs from their forced degradation peaks. For verification of peak identity and purity, the diode-array detector (DAD) was used. In addition, degradation pathways for the cited drugs were postulated. Furthermore, separation of both analytes from about 13 medicinal compounds of different therapeutic classes disclosed optimum specificity of the proposed method.
Advantageous application of the validated HPLC method for the concurrent analysis of ALO/THA in their tablet dosage form was accomplished.
So far, the described HPLC-DAD method is considered the first detailed stability-indicating analytical study for this pharmaceutical mixture.
仔细审查科学数据库后发现，尚无可用于检测别嘌醇（ALO）和硫辛酸（THA）混合物的稳定性指示分析方法。
建立了一种全面的 HPLC-DAD 稳定性指示方法，用于同时分析 ALO 和 THA。
采用 Durashell C18 柱（4.6×250mm，5μm 粒径）成功实现了参比药物的色谱分离。流动相由酸化水（pH 4.0）和用磷酸泵入的乙腈组成，采用梯度洗脱模式。为了定量分析 ALO 和 THA，分别在 249nm 和 210nm 处记录其各自的峰面积。从系统适用性、线性、范围、精密度、准确度、专属性、耐用性、检测限和定量限等方面对分析性能进行了系统验证。
ALO 和 THA 的色谱峰分别在 4.26 和 8.15min 时出现。ALO 和 THA 的线性范围分别为 5-100μg/mL 和 10-400μg/mL，相关系数均大于 0.9999。两种药物均暴露于中性、酸性和碱性水解、氧化和热分解条件下。通过将药物与强制降解峰分离，证明了该方法具有稳定性指示特征。为了验证峰的纯度和峰的纯度，使用二极管阵列检测器（DAD）。此外，还提出了参比药物的降解途径。此外，从 13 种不同治疗类别的药用化合物中分离出两种分析物，显示出该方法具有最佳的专属性。
验证后的 HPLC 方法可用于同时分析其片剂制剂中的 ALO/THA。
到目前为止，所描述的 HPLC-DAD 方法被认为是针对该药物混合物的首个详细的稳定性指示分析研究。
