What factors affect the Metered Dose Inhaler Drug Delivery?

When you press the canister of the Metered dose inhaler, you receive a dose of medication, but remember that only 20-30% of the total inhaled dose is actually delivered to your lung airways. You can see that using your Metered dose inhaler device properly is extremely important. So you need to know what factors can affect the performance of your drug delivery.

Shaking the inhaler:
If you have not used your Metered dose inhaler for an extended period of time, the medication and the propellant in the inhaler device can get separated. So you need to shake the inhaler at least for 5 seconds each time before you use the inhaler. Not shaking the Metered dose inhaler can reduce the delivered dose of medication by as much as 30%.

Storing the inhaler device:
For best results, pMDI should be stored at or near room temperature, if metered dose inhaler is left in a cold place overnight, the inhaler might not work until it returns to the normal room temperature.

Cleaning the inhaler device:

If you see any buildup on the nozzle of the actuator such as white residue, you should clean the inhaler device. Metered dose inhaler devices can become contaminated with dirt, debris, and even bacteria from you and/or the environment. If you are not vigilant in the proper care and handling of your inhaler device, serious infection-related and cross contamination problems can occur.

Priming:
At times the dose remains in the metering chamber and is about to be inhaled in the airway with the next actuation. This uncertain dose should be released into the air. This is called priming. So Metered dose inhalers that are new or have not been used for a period of time, should be primed before inhaling. Simple shake the inhaler, press the inhaler and release 1-2 sprays in the air to ensure proper release of medicine.

Source: www.ncbi.nlm.nih.gov