Abdelaleem Eglal A, Abdelwahab Nada S
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Bani-Sueif University, Alshaheed Shehata Ahmad Hegazy St., 62514, Beni-Suef, Egypt.
J Chromatogr Sci. 2013 Feb;51(2):187-91. doi: 10.1093/chromsci/bms125. Epub 2012 Jul 26.
A highly sensitive, selective and accurate thin-layer chromatographic (TLC)-densitometric method has been developed and validated for the simultaneous determination of paracetamol (PAR) and chlorzoxazone (CZ) and their toxic impurities, 4-amino phenol (4AP) and 2-amino-4-chlorophenol (2ACP), respectively, which are also considered to be the hydrolytic degradation products and related substances of the studied drugs. A developing system consisting of chloroform-methanol-glacial acetic acid (9.5:0.5:0.25, by volume) was found to be sufficient for chromatographic separation among the four studied components using pre-activated silica gel 60 F254 TLC plates with ultraviolet detection at 225 nm. Calibration curves were constructed in the ranges of 0.3-3, 1-10, 0.06-3 and 0.04-3 µg/band for PAR, CZ, 4AP and 2ACP, respectively, using polynomial equations. The developed method was validated according to International Conference on Harmonization guidelines and demonstrated good accuracy and precision. Moreover, the method was successfully applied for the determination of PAR and CZ in different marketed samples and the results were statistically compared to those obtained by the reported reversed-phase high-performance liquid chromatography method using F-test and Student's-t test. The low detection and quantitation limits of the developed method make it suitable for quality control and stability studies of PAR and CZ in different pharmaceutical formulations.
已开发并验证了一种高灵敏度、高选择性且准确的薄层色谱（TLC）-密度测定法，用于同时测定对乙酰氨基酚（PAR）和氯唑沙宗（CZ）及其有毒杂质4-氨基苯酚（4AP）和2-氨基-4-氯苯酚（2ACP），这两种杂质也被认为是所研究药物的水解降解产物和相关物质。发现由氯仿-甲醇-冰醋酸（体积比为9.5:0.5:0.25）组成的展开系统足以使用预活化硅胶60 F254 TLC板在225 nm处进行紫外检测，对四种研究成分进行色谱分离。分别使用多项式方程在0.3 - 3、1 - 10、0.06 - 3和0.04 - 3 μg/条带范围内构建PAR、CZ、4AP和2ACP的校准曲线。所开发的方法根据国际协调会议指南进行了验证，显示出良好的准确性和精密度。此外，该方法成功应用于不同市售样品中PAR和CZ的测定，并使用F检验和学生t检验将结果与报道的反相高效液相色谱法获得的结果进行统计学比较。所开发方法的低检测限和定量限使其适用于不同药物制剂中PAR和CZ的质量控制和稳定性研究。
