The present invention relates to stable once daily sustained release pharmaceutical compositions comprising pregabalin or pharmaceutically acceptable salts thereof and a pharmaceutically acceptable excipient wherein pharmaceutical composition is bioequivalent to conventional immediate release formulation of pregabalin administered twice daily. The present invention further relates to a composition comprising pregabalin and sugar esters as release retarding agent for maintaining uniform release rate of the drug and process for the preparation of such oral sustained release formulations.
