Validating a Stability Indicating HPLC Method for Kinetic Study of Cetirizine Degradation in Acidic and Oxidative Conditions

A stability indicating High-Performance Liquid Chromatography (HPLC) method wasvalidated and used to study the degradation of cetirizine dihydrochloride in acidic and oxidativeconditions. The separation was carried out on a Symmetry C18 column and a mixture of 50 mMKH2PO4 and acetonitrile (60:40 v/v, pH = 3.5) was used as the mobile phase. The method waslinear over the range of 1-20 μg/mL of cetirizine dihydrochloride (r2 > 0.999) and the withindayand between-day precision values were less than 1.5%. The results showed that cetirizinedihydrochloride was unstable in 2 M HCl and 0.5% H2O2. The kinetics of the acidic degradationshowed a pseudo-first-order reaction in the temperature range of 70-90°C. In addition, thekinetics of hydrogen peroxide mediated degradation was pseudo-first-order in the temperaturerange of 50-80°C.