» Acetylcysteine and Isoproterenol Hydrochloride Inhalation Solution is a sterile solution of Acetylcysteine and Isoproterenol Hydrochloride in water. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of acetylcysteine (C₅H₉NO₃S), and not less than 90.0 percent and not more than 115.0 percent of the labeled amount of isoproterenol hydrochloride (C₁₁H₁₇NO₃·HCl).