Aceclofenac is a phenyl acetc acid derivative which have antiinflamatory and analgesic property. Aceclofenac directly block PEG-2 secretion at the site of inflamation by inhibit IL and TNF in the inflamatory cells. Aceclofenac block degeneration and stimulets synthesis of extracellular matrix of cartilage by inhibit of cytokines. So its used in rheumatoid arthrits, osteoarthertis and ankylosing spondylitis. Aceclofenac have acedic moity which produce stomuch ulcer.Prevent stomuch ulcer by enteric coating.