It is provided a once-daily controlled-release formulation of diacerein fortreating inflammatorydiseases, autoimmune diseases or their complications with reduced adverse sideeffects and methods oftreating such diseases are disclosed, wherein the formulation comprises anactive layer, asustained-release film layer, and a delayed-release film layer, wherein saidsustained-release film layer comprisesan ethyl cellulose polymer, povidone, triethyl citrate and talc, and whereinthe delayed-release film layercomprises an Eudragit® polymer, triethyl citrate and talc.