Naproxen EP Impurity J with CAS No: 21388-17-0 is an impurity standard of Naproxen. Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) that is commonly used to relieve pain, reduce inflammation and lower fever. Naproxen, like other NSAIDs, works by inhibiting enzymes known as cyclooxygenases (COX-1 and COX-2). Naproxen is available in various forms, including tablets, capsules, and oral suspensions. Buy high quality Naproxen EP Impurity J from Molsyns Research. Molsyns Research is one of the leading manufacturer and exporter of Naproxen EP Impurity J