Abstract: The present invention relates to a layered pharmaceutical composition comprising: a first layer of sustained-release bupropion or its pharmaceutically acceptable salts, a second layer of sustained-release naltrexone or its pharmaceutically acceptable salts, with pharmaceutically acceptable excipients, and an intermediate inert layer that provides a time-controlled disintegration to allow separation of two drug layers and maintain their physical integrity as a single tablet. It further provides the methods for preparing the said pharmaceutical compositions for the treatment of obesity-related conditions.