Epinephrine Inhalation Aerosol USP, a HFA-MDI Study for Assessment of Pharmacokinetics

E004 is formulated with epinephrine free base as the active ingredient, and hydrofluoroalkane (HFA-134a) as the propellant. In order to differentiate the inhaled epinephrine from the fluctuating background of endogenous epinephrine 1, a stable-isotope deuterium (2H) labeled epinephrine (epinephrine-d3) preparation will be used to formulate E004 inhalers, denoted as E004-d3. PK of E004 at 125 mcg of epinephrine-d3 per inhalation, will be compared to that of the currently marketed, non-labeled, Epinephrine-CFC MDI as the Reference Control (220 mcg per inhalation). This study is a randomized, evaluator-blind, single dose, two-arm, crossover, PK study, to be conducted in \~18 healthy, male and female, adult volunteers. PK will be studied using E004-d3 at 125 mcg per inhalation (Arm T). A currently marketed, non-labeled, Epinephrine CFC-MDI will be used as a Reference Control (Arm C).