There are a number of ways to deliver inhaled medication. They include:
*Metered-dose inhaler (MDI)
*Metered-dose inhaler with spacer/holding chamber
*Dry Powder Devices
The metered-dose-inhaler is important for the treatment of chronic lung disease, including asthma and COPD. A variety of medicines are available in a metered-dose-inhaler. The metered dose inhaler (MDI) consists of a pressurized canister of medicine in a plastic case with a mouthpiece. A holding chamber consists of a plastic tube with a mouthpiece, a valve to control mist delivery and a soft sealed end to hold the MDI. The holding chamber assists delivery of medicine to the lungs. The metered-dose inhalers contain an hydrofluoroalkane propellant,aka HFA propellant, or hydrofluoroalkane 134a.