A validated stability‐indicating reversed‐phase‐HPLC method for dipyridamole in the presence of degradation products and its process‐related impurities in pharmaceutical dosage forms

In this study, we developed and validated a method to determine dipyridamole‐related impurities in pharmaceutical dosage forms using the reversed‐phase‐HPLC technique. All impurities were separated on a YMC pack C8 (150 mm × 4.6 mm, 3.0 μm) analytical column using a suitable mobile phase. Mobile phase A was 10 mM concentration of phosphate buffer (pH adjusted to 4.7 by adding diluted orthophosphoric acid) and mobile phase B was buffer:acetonitrile:methanol (at the ratio of 30:40:30 v/v). The optimized chromatographic conditions used in the experiment were as follows: flow rate, 1.0 mL/min; injection volume, 10 μL and column temperature, 35°C. Chromatographic detection was performed at 295 nm. The stressed samples were analyzed for degradation under acidic, basic, peroxide, water hydrolysis, and physical degradation conditions. The proposed method was validated according to International Conference on Harmonization (ICH) guidelines, and found to be specific, linear, accurate and have a robust stability‐indicating nature. The method showed excellent linearity from limit of quantification (LOQ) to 150% level of concentrations for all impurities. The correlation coefficient (r2) for all impurities was between 0.995 and 0.999. The recovery study was performed from LOQ to 150% level concentrations, with mean recovery values between 92.9% and 103.2%, respectively. The developed method can be used to determine dipyridamole and its relative impurities. The degradation and validated study results indicate its stability‐indicating nature. Therefore, the method can be used in pharmaceutical research and development and quality control departments.