» Isoproterenol Hydrochloride and Phenylephrine Bitartrate Inhalation Aerosol is a suspension of microfine Isoproterenol Hydrochloride and Phenylephrine Bitartrate in suitable propellants in a pressurized container. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amounts of isoproterenol hydrochloride (C₁₁H₁₇NO₃·HCl) and phenylephrine bitartrate (C₉H₁₃NO₂·C₄H₆O₆).