Determination of degradation products from the calcium-channel blocker isradipine.

Mass Spectrometry has been used to determine the identity of a number of degradation products from the bulk drug form of Isradipine (DynaCirc). Liquid chromatography coupled with mass spectrometry (LC/MS) was used to analyze the degraded samples and tentative identifications were made based upon the known reactivity of the molecule, molecular weight measurements and mass spectral fragmentation patterns. Isradipine was found to be stable to heating, acidic and basic conditions, but susceptible to degradation from exposure to UV light and oxidative processes.