Compositions and methods are provided for obtaining stabilized quinol compositions, such as catecholamine drugs (e.g., epinephrine solutions), and also for obtaining stable pharmaceutical formulations that comprise a stabilized quinol composition and a second pharmacologically active component such as a local anesthetic or other active drug ingredient having a reversibly protonated amine group. Stability is achieved through the inclusion of an appropriately selected pH buffer and a thiol agent, based on redox and pH buffering principles including pKa of the buffer and of the reversibly protonated amine group.
