The present invention is related to a novel gastroretentive swellable oral dosage form for sustained or delayed release of bergenin, a active constituent of Bergenia ciliata extract/fraction and a process for preparing the same wherein the extract is wet-granulated using excipients i.e. biodegradable polymers and/ or non-biodegradable polymers alone or in combination, and the said granules are either filled into a capsule or compressed into a tablet. The said formulation comprising a granulated extract of bergenin-rich Bergenia ciliata with polymers has resulted in a sustained release of extract in the stomach over a period of 16-24hrs. The said formulations are useful for the treatment of inflammatory diseases.
