Impurity profiling HPLC–UV/PDA method development, validation and relative response factor estimation for budesonide, glycopyrronium and formoterol fumarate combination product

Budesonide, glycopyrronium and formoterol fumarate triple combination medicinal products are prescribed across the world for curing the various lung disorders. To ensure the quality and safety of these medicines, there is a need of impurity quantitation analytical methodology. The study aimed to develop and validate a new RP-HPLC single-run impurity quantitation methodology. Chromatographic separation was achieved using Bakerbond C18, 5 µm, 250 × 4.6 mm HPLC column maintained at 35ºC in a gradient mode of 0.8 mL/min flow with mobile phase A (pH-2, mixture of 5.44 g/l potassium dihydrogen phosphate (KH2PO4) and 0.5 g/l sodium 1-octanesulfonate (C8H17O3SNa) buffer), and mobile phase B (mixture of acetonitrile: methanol 90:10%v/v). Mixture of methanol, and water (50:50%v/v) used as a diluent. Glycopyrronium and formoterol impurities were detected at 220 nm, and budesonide impurities at 240 nm. For all the reported 9 known impurities successfully determined the relative response factors. The method was found to be selective, stability indicating and able to quantify accurately known as well as unknown impurities with low LOD and LOQ values. The method was found to be linear with correlation coefficient (r) > 0.97, precise (%RSD- 2.95–11.31), and accurate (recovery in a range of 90.9–113.8%) for all the impurities and active drugs. The stability of components in the analytical solution was found for 2d (48 h). The method was validated successfully according to ICH Q2(R2) guidelines, confirming its suitability for the intended use. This method can be applicable in the quality control laboratories of pharmaceutical industries for the impurity determination.