• Horizon Pharma Inc., of Deerfield, Ill., and Mallinckrodt LLC, the pharmaceuticals business of Covidien LLC, of Dublin, Ireland, signed a U.S. co-promotion agreement for Duexis (ibuprofen and famotidine) to relieve symptoms of rheumatoid arthritis and osteoarthritis and to decrease the risk of developing upper gastrointestinal ulcers.