Wyeth Pharmaceuticals has ended its collaboration agreements with Solvay Pharmaceuticals for the development and commercialization of bifeprunox, an investigational atypical antipsychotic drug, as well as other compounds in earlier stages of development for the potential treatment of schizophrenia and other psychiatric conditions.     The collaboration was terminated after Wyeth assessed the opportunity for bifeprunox, and determined it would not have sufficient commercial value for the two c...