[Investigation of tofizopam impurities using high performance liquid chromatography]

The identification and quantification of potential impurities of Tofisopam have been studied by high performance liquid chromatography. The best separation was obtained in a reversed phase system using a C18 stationary phase and 46:31:23 mixture of 0.01 M aqueous 1-hepatanesulphonic acid-sodium-acetonitrile-methanol as the mobile phase. System suitability parameters and method validation are also presented and discussed. The elaborated method was suitable for the determination of the conformational isomer ratio of Tofisopam in various solvents and for the evaluation of Challenge Test.