Abstract

Piribedil is an antiparkinson agent, available as Clarius Prolonged release tablet in Germany. No analytical method is reported for estimation of impurities in Piribedil. The objective of this work was to develop a stability indicating method for estimation of impurities in Piribedil Tablets by using quality by design approach. Piribedil and its impurities are having different absorption maxima hence known impurities and unknown impurities were quantified at 210 nm and 238 nm respectively. Phosphate buffer (pH 4.3; 25 mM) and mixture of Phosphate buffer, Methanol, Acetonitrile (30:40:30, v/v respectively) were used in gradient elution mode. Zorbax SB Phenyl (150 x 4.6) mm, 3.5 µm column was used for separation. Mobile phase was delivered at a flow rate of 1.0 mL/minute and column was maintained at 45°. Injection volume was optimized as 10 µl. Critical chromatographic parameters such as Column oven temperature and pH of buffer were optimized by performing Design of experiments. Forced degradation studies were performed and all the degradants formed during forced degradation, were well separated from known impurities and from Piribedil peak. Mass balance was found more than > 98% in all the stressed conditions. The developed method was validated and found specific, precise, linear, accurate, rugged and robust.