The present invention is related to the novel oral dosage form for sustained release of crocin-1, a active constituent of Crocus sativus extract or fraction and a process for preparing the same wherein the extract is wet-granulated using excipients, biodegradable polymers and/or non-biodegradable polymers alone or in combination. The said formulations are useful for the treatment of chronic inflammatory diseases wherein NLRP3 inflammasome is involved.