Forced Degradation Studies of Olmesartan Medoxomil and Characterization of Its Major Degradation Products by LC-MS/MS, NMR, IR and TLC

Abstract

The proposed study describes an isocratic reversed phase HPLC method for investigation of degradation products of Olmesartan medoxomil API under different stress conditions (acid hydrolysis degradation). Separation of Olmesartan medoxomil and its degradation products was achieved on symmetry C18 (150 mm × 4.6 mm, 5 μ) column using a Acetonitrile: 0.02 M Na2HPO4(45: 55 v/v) mobile phase and pH 7 adjusted with ortho phosphoric acid. Isocratic elution mode at a flow rate of 1.0 ml/min at Room temperature with a load of 20μl Injection volume. The detection was carried out at 240 nm followed by Base hydrolysis Structures of the degradation products were studied using a Triple Quadrapole Mass Spectrometer. A separate gradient LCMS method was developed for this purpose Depending on the degradation type, possible chemical reactions were predicted and supported by fragmentation data obtained from LC-MS/NMR. One major products were obtained in solid form using Rotavap and were then analyzed by NMR, IR and TLC to confirm their structural details.