Development of stability-indicating method for separation and characterization of benidipine forced degradation products using LC-MS/MS.

The present study describes forced degradation of benidipine (BEN) as per  Q1A (R2) and Q1B guidelines of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. BEN degraded under hydrolysis (neutral, acidic, and alkaline), hydrogen peroxide induced oxidation, and UV light mediated photolytic degradation. A total of 14 degradation products (DPs) were found in all degradation studies, comprising 4 hydrolytic DPs, 8 oxidative DPs, and 4 photolytic DPs. A selective stability-indicating method was developed using an XBridge BEH C18 column with gradient elution program consisting of ammonium acetate (10 mM, 4.8 pH, acetic acid) and acetonitrile. The flow rate was maintained at 1 ml min -1 . All DPs were separated well using the developed HPLC method and were characterized using LC-MS/MS data. As this method is effective in identifying and separating BEN and its DPs with sufficient resolution, it can be used in laboratories for quality control of drugs in daily routine analysis and stability studies.