The objective of the present study was directed towards developing a colon specific drug delivery system of aceclofenac, the non-steroidal anti-inflammatory drug associated with circadian rhythm of chronobiological symptoms for effective management of rheumatoid arthritis. Aceclofenac is a cox 2 selective inhibitor and has better safety than conventionalnon-steroidal anti-inflammatory drugs with respect to adverse effects on gastrointestinal and cardiovascular system. Aceclofenac is rapidly and completely absorbed after oral administration. Peak plasma concentration reaches in 1-3 h after an oral dose. The plasma elimination half life of the drug is approximately 4 h. The chronopharmacological approach for the management of rheumatoid arthritis has been well documented. Considering this factor, aceclofenac under investigation in the present study was developed as a colon targeted delivery system through tablets, pellets and microspheres. Additionally a Pulsincap drug delivery of the drug was also studied to meet the objective of circadian rhythm in rheumatoid arthritis.