Extended release oral dosage composition

A bilayer solid composition comprising (a) an immediate release first layer comprising an anti-allergic effective amount of desloratadine and at least one pharmaceutically acceptable excipient and (b) a sustained release second layer comprising an effective amount of a nasal decongestant, e.g. pseudoephedrine sulfate and a pharmaceutically acceptable sustained release agent wherein the composition contains less than about 2% of desloratadine decomposition products is disclosed. A solid composition comprising an anti-allergic effective amount of desloratadine and at least one, and preferably two pharmaceutically acceptable antioxidants is also disclosed.