Quality by design-based development and optimization of a novel, dual wavelength HPLC method for determination of impurities in piribedil prolonged release tablets

Abstract

The objective of this investigation was to develop a stability-indicating method for the estimation of impurities in piribedil tablets using the quality by design approach. Piribedil and its impurities have different absorption maxima hence known and unknown impurities were quantified at 210 and 238 nm, respectively. Phosphate buffer (pH 4.3) and a mixture of phosphate buffer, methanol, and acetonitrile (30:40:30, v/v) were used in gradient elution mode. Zorbax SB Phenyl (150×4.6 mm, 3.5 μm) column was used for separation. Mobile phase was delivered at a flow rate of 1.0 ml/min and column was maintained at 45°. Injection volume was optimized as 10 μl. Critical chromatographic parameters such as column oven temperature and pH of the buffer were optimized by design of experiments. Forced degradation studies were performed and all the degradants formed were well separated from known impurities and from piribedil peak. Mass balance was found to be > 98% in all stressed conditions. The developed method was validated and found specific, precise, linear, accurate, rugged and robust.