Aromasin Exemestane was approved in 1999 and popularly used for breast cancer treatment. It was originally manufactured by Pharmacia and Upjohn at that time but today Pfizer is the popular brand name for its production. Aromasin comes under the class of aromatase inhibitor and its common inactive ingredients are: mannitol, hypromellose, microcrystalline cellulose, magnesium stearate, polyethylene glycol 6000, titanium dioxide, polyvinyl alchohol, crospovidone, colloidal silicon dioxide, sodium starch glycolate, simethicone, sucrose, methylparaben, polysorbate 80 and magnesium carbonate. The active component of Exemestane is crystalline powder which is of slightly yellowish colour and its molecular weight is 296.41. Aromasin is insoluble in water whereas it acts as a soluble substance for methanol and N-dimethylformamide.