An efficient, commercially viable and safe process for the preparation of losartan potassium, an antihypertensive drug substance, with an overall yield of 55.5% and ∼99.9% purity (including five chemical reactions and two recrystallizations) and meeting all other regulatory requirements is described. Formation and control of all the possible impurities are also described.

An improved process for the preparation of gemfibrozil, an antihypolipodimic drug substance, with an overall yield of 80% and ∼99.9% purity (including three chemical reactions) is reported. Formation and control of possible impurities are also described. Finally, gemfibrozil is isolated from water without any additional solvent purification.