Why do MDIs contain propellants?
MDIs use a chemical propellant to push medication out of the inhaler. Two common propellants are CFCs and HFAs (hydrofloroalkanes). HFAs are ozone-safe propellants and are replacements for ozone-depleting CFCs in many sectors. Neither CFCs nor HFAs are medications; they serve only as the propellant that pushes the medication out of the inhaler. There are a variety of active medications that can be contained within MDIs, such as albuterol, flunisolide, cromolyn, and epinephrine.
