Inside an MDI canister

Arguably, the most important aspect of a Metered Dose Inhaler is the fact that it delivers (as the name implies) a metered dose. But how is it able to do this? We disassembled an empty canister to find out...

PS: Do not attempt this yourself. The canister is highly pressurised.

MDI Canister

Aside from the main aluminium body, the canister includes intricate plastic components to form a valve which temporarily stores the set amount of medicine (in powder form) before releasing it when activated. The aluminium cover is not pictured, due to the fact that it was destroyed beyond recognition in the process of disassembly.