Stability-indicating assay method for estimation of olmesartan medoxomil and its metabolite

A novel stability indicating high performance liquid chromatographic assay method was developed and validated for Olmesartan medoxomil and its degradant product. An isocratic HPLC method was developed to separate the drug from the degradation products, using an Inertsil-ODS-3 (C-18) Column (5 µm, 250 mm × 4.60 mm). A mixture of phosphate buffer (pH 4.0) and methanol (30:70) was used as mobile phase. The flow rate was 1.0 mL/min and the detection was carried out at 230 nm. The validation studies were carried out fulfilling the International Conference on Harmonisation (ICH) requirements. The procedure was found to be specific, linear, precise (including intra and inter day precision), accurate, and robust.