Provided herein is technology relating to deuterated amlexanox and particularly, but not exclusively, to compositions comprising deuterated amlexanox, methods of producing deuterated amlexanox, and uses of deuterated amlexanox. In one embodiment, the barrel portion of the bat may have a polymer layer directly laid up upon the metal bat frame. In the switching circuit, each of terminals is connected to any of terminals based on the switching control signal.