ISOLATION AND CHARACTERISATION OF FORCED DEGRADATION PRODUCTS OF A CALCIUM CHANNEL BLOCKER BY LC/MS TECHNIQUE

The current study aims in carrying out forced degradation studies on Cilnidipine, a calcium channel blocker and identifying the degradants obtained when the drug is subjected to various stress conditions forcefully. The separation was carried out using Shimadzu, LC/MS model 8030 with lab solutions 5.72 B as software and a PDA detector. The wavelength selected was 240 nm with a flow rate 1.00ml/min. The column temperature was 40±0.3°C and the run time was 18 min. The volume taken for injection was 5.0 μl. Phase A (0.1 % Formic acid in methanol: Acetonitrile in the ratio 80:20 v/v): phase B, (10 mM ammonium acetate) in gradient mode was used as a mobile phase. Cilnidipine when forced to degradation by various methods showed degradation showed four major degradants in basic conditions. From the mass spectra of the degradants, a probable structure was identified. Cilnidipine showed degradation only in basic conditions while remained stable under acidic, oxidative and photolytic conditions.