In Vitro Competitive Metabolism Study of Olmesartan Medoxomil in Rat Liver S9 Fractions Using LC/MS

Abstract

Olmesartan Medoxomil (OLM), Ramipril (RPL) & Fenofibric acid (FA) are used to treat hypertension and cardiovascular disease. These drugs undergo hydrolytic metabolism by the enzyme liver esterase and converts into their respective active metabolites Olmesartan (OL), Ramiprilat (RPT) and Fenofibric acid (FA) for OLM, RPL and FEN respectively. In this study the competitive metabolism of OLM, in presence of RPL and FEN was investigated in rat liver s9 fractions using a validated LC-MS method. Olmesartan Medoxomil was found to be highly reactive to the rat liver S9 fractions and formation of active metabolite Olmesartan is highest. The rate of formation of active metabolite Olmesartan reduced by 12.68% in the presence Ramipril and 6.56% in presence of Fenofibrate. A marked reduction of 18.96% was found in the formation of active metabolite Olmesartan from Olmesartan Medoxomil when all the three drugs are in combination.