Forced Degradation Products of Olmesartan Medoxomil and their In Vitro Genotoxicity Assessment by Comet Assay using HEK Cells

This study designed to characterize major forced degradation products of Olmesartan Medoxomil (OM) and to perform genotoxicity profiling using acid, base, and hydrogen peroxide-induced stress degradation studies. The isolation of degradation products was conducted on flash chromatography using FlashPure ECOFLEX C-18 4 g column with gradient elution and diode array detection-based fraction collection, and characterized by mass spectrometry. Three impurities (impurity-1, 2, and 3) were identified with respective m/z values of 447.213, 461.229, and 463.208. The genotoxic potential of impurities was assessed by in silico prediction, and in vitro comet assay using HEK cells. The extent of DNA damage was analyzed using Comet Assay IV imaging software. For impurity-1, head and tail lengths and their respective total intensities were significantly (p<0.001) larger than those of dimethyl sulfoxide (solvent) control and comparable to positive control. Other parameters such as mean grey level and total area of comet were statistically significant as compared with the solvent and positive controls. Overall, impurity-1 was a possible genotoxic impurity and a known major degradation product in OM tablet dosage form. In silico prediction also revealed impurity-1 as toxicity class 3, whilst impurities 2 and 3 were of toxicity class 4.