Method development and validation for pyrogallol content quantification by hplc in trimetazidine dihydrochloride

Trimetazidine dihydrochloride (TD) is an anti-ischemic drug that is used to effectively treat angina pectoris symptoms. During the manufacture of TD from gallic acid a process related impurity, pyrogallol, is produced. Up to the present time, no appropriate method has been proposed for the detection and analysis of pyrogallol in the TD at the level of threshold of toxicological concern. Therefore, in this investigation, a reliable and reproducible HPLC method was developed for the detection and analysis of pyrogallol in the TD. The method was validated in full compliance with the recommendations of the International Harmonization Council. Regression analysis indicated a correlation coefficient value of 0.9990 for pyrogallol between 6.3 ppm and 31.5 ppm. The LOD was 1.89 ppm and LOQ was 6.3 ppm for pyrogallol. Good recovery (accuracy) was observed in the range of 98.34% to 118.54% with an RSD value (precision) of 0.150%. Pyrogallol analysis in batches TD material has demonstrated the good performance of the method. The process is therefore useful in the identification and evaluation of pyrogallol content in drug substance of TD.