Development and Validation of HPLC Methods for the Determination of Propranolol Hydrochloride and Hydrochlorothiazide Related Substances in Combination Tablets

A recent study shows that propranolol hydrochloride (PRO) related substances may also reduce the stability of tablets in storage. Therefore, it is necessary to control the level of PRO related substances in tablets. However, the analysis in U.S. pharmacopoeia could not detect PRO related substances. To overcome this, we developed a new method which can detect PRO, hydrochlorothiazide (HCT) and all of their impurities. In this study, validation studies were also performed, linear relationship with a good correlation coefficient (r2)u003e0.990 was found of both PRO impurities and HCT impurities in the range of 0.12-0.60, and 0.15-0.75 μg/ml respectively. Acceptable intra- and inter- assay precisions were achieved. Accuracy and robustness were reported as percent recovery, and all the recoveries were at the range of 70-130%. After validation, the methods were successfully used in the routine quality control of the tablets.