A novel reversed-phase liquid chromatographic method for the simultaneous determination of potential impurities of bisoprolol fumarate and hydrochlorothiazide in a fixed dosage form

In the present study 12 impurities of bisoprolol fumarate (BISO) and hydrochlorothiazide (HCTZ) were separated simultaneously in a single HPLC method. Out of these 12 impurities, five are potential degradants, which are validated as per The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. As the two active drug substances BISO and HCTZ have different solubilities and polarities, the most critical parameters in resolving the components from each other are pH, temperature, and solvents. The method is precise (RSD 0.999), robust, and stability indicating in the range of limit of quantification (LOQ) to 150%. The HPLC method is then migrated to ultra-performance liquid chromatography (UPLC) to further reduce the run time and solvent consumption, and increase the sample throughput.