Stable compositions of bupropion or its pharmaceutically acceptable salts

A stable oral pharmaceutical composition comprising a therapeutically effective amount of bupropion or its pharmaceutically acceptable salt intimately blending with one or more compatible excipients selected from the group consisting of talc and potassium chloride, additional pharmaceutically acceptable excipients and total impurities are present in amounts from 0% to not more than 3.3% w/w of the bupropion hydrochloride, when the composition is stored at 40° C. at 75% relative humidity for three months in closed containers with silica gel as dessicant.