Raju Thummala Veera Raghava, Seshadri Raja Kumar, Arutla Srinivas, Mohan Tharlapu Satya Sankarsana Jagan, Rao Ivaturi Mrutyunjaya, Nittala Someswara Rao
Analytical Research and Development, Integrated Product Development, Dr. Reddy's Laboratories Ltd., Bachupally, Hyderabad-500072, India.
Sci Pharm. 2013 Jan-Mar;81(1):123-38. doi: 10.3797/scipharm.1209-17. Epub 2012 Nov 5.
A novel, sensitive, stability-indicating HPLC method has been developed for the quantitative estimation of Tolperisone-related impurities in both bulk drugs and pharmaceutical dosage forms. Effective chromatographic separation was achieved on a C18 stationary phase with a simple mobile phase combination delivered in a simple gradient programme, and quantitation was by ultraviolet detection at 254 nm. The mobile phase consisted of a buffer and acetonitrile delivered at a flow rate 1.0 ml/min. The buffer consisted of 0.01 M potassium dihydrogen phosphate with the pH adjusted to 8.0 by using diethylamine. In the developed HPLC method, the resolution between Tolperisone and its four potential impurities was found to be greater than 2.0. Regression analysis showed an R value (correlation coefficient) of greater than 0.999 for the Tolperisone impurities. This method was capable of detecting all four impurities of Tolperisone at a level of 0.19 μg/mL with respect to the test concentration of 1000 μg/mL for a 10 µl injection volume. The tablets were subjected to the stress conditions of hydrolysis, oxidation, photolysis, and thermal degradation. Considerable degradation was found to occur in base hydrolysis, water hydrolysis, and oxidation. The stress samples were assayed against a qualified reference standard and the mass balance was found to be close to 100%. The established method was validated and found to be linear, accurate, precise, specific, robust, and rugged.
已开发出一种新颖、灵敏、指示稳定性的高效液相色谱法，用于定量测定原料药和药物制剂中托哌酮相关杂质。在C18固定相上，通过简单的流动相组合并采用简单的梯度程序实现了有效的色谱分离，定量检测采用254nm紫外检测。流动相由一种缓冲液和乙腈组成，流速为1.0ml/min。缓冲液由0.01M磷酸二氢钾组成，用二乙胺将pH调至8.0。在所开发的高效液相色谱法中，托哌酮与其四种潜在杂质之间的分离度大于2.0。回归分析表明，托哌酮杂质的R值（相关系数）大于0.999。对于10µl进样体积、1000µg/mL的测试浓度，该方法能够检测到所有四种托哌酮杂质，检测限为0.19µg/mL。对片剂进行了水解、氧化、光解和热降解等强制降解试验。发现碱水解、水水解和氧化过程中发生了显著降解。对强制降解样品与合格的参比标准品进行测定，质量平衡接近100%。所建立的方法经过验证，具有线性、准确性、精密度、特异性、稳健性和耐用性。
