Oxaprozin (4,5-diphenyl-2-oxazolepropionic acid) is a an effective and well-tolerated non steroidal anti-inflammatory drug (NSAID) which is indicated for the short and long-term treatment of symptoms of osteoarthritis, adult rheumatoid arthritis, ankylosing spondylitis, musculoskeletal and other painful acute peri-articular disorders and acute articular gout.

Oxaprozin chemically belongs to the class of the propionic acid derivatives and it shows interesting pharmacokinetics properties. The long plasma half-life of this drug is about 50-60 hours,j which allows the once a day administration. Moreover Oxaprozin shows dual (renal and faecal) elimination pathways that may reduce the risk of disproportionate drug accumulation and toxicity when this drug is used in the elderly and compromised patients.
Oxaprozin also reaches high concentrations in synovial tissue. The clinical efficacy of Oxaprozin especially in osteoarthritis and rheumatoid arthritis is well documented by a large number of controlled clinical trials, where this drug was favourably compared with other NSAIDs. The results of these trials demonstrate that Oxaprozin 1200mg/die has equal or even superior efficacy in comparison with aspirin, ibuprofen, indomethacin, nabumetone, naproxen, piroxicam and diclofenac.
Oxaprozin has proved to be well tolerated. Mild gastrointestinal complaints (e.g. nausea, diarrhoea, constipation, gastralgia and occasionally vomiting) are, as with other NSAIDs, the most frequently occurring adverse events with Oxaprozin.

Helsinn acquired from Wyeth the exclusive worldwide licensing rights, excluding USA, Canada and Japan.
Helsinn’s Oxaprozin was first marketed in Italy in 2000, followed by numerous other launches in Europe and Latina America under the trademarks: Dayrun®, Danoprox®, Duraprox®, Flusyd® and Walix®.

Helsinn has licensed-out Oxaprozin to various multinational and national pharmaceutical companies, according to the list below:
Biomeks, CSC Group, Fidia, Gerolymatos, Novamed, Sanofi Aventis, Silesia, Sulkaj, Tramedico.