AbstractThe effects of prolonged heat exposure on the stability of various epinephrine formulations (maleate, fumarate, HCl, and bitartrate) were studied with respect to mass loss and pressor potency. Mass loss was relative to length of incubation and was accompanied by discoloration in HCl and bitartrate. Fumarate and maleate demonstrated least loss of mass and little discoloration. Pressor potency was significantly reduced, relative to length of heat exposure, in HCl and bitartrate, but remained elevated in fumarate and maleate. Thus, the latter formulation demonstrate the highest thermostability.