The present invention relates to pharmaceutical compositions containing a synergistic amount of at least one bone morphogenetic protein (BMP) and a synergistic amount of at least one pyrrolidone optionally in a pharmaceutically acceptable carrier, such as a biodegradable polymer. The present invention further relates to methods of treating orthopaedic and dental, including periodontal, diseases by simultaneously administering a synergistic amount of at least one bone morphogenetic protein (BMP) and a synergistic amount of at least one pyrrolidone optionally in a pharmaceutically acceptable carrier to patients in need of such treatment.