Aerosol-Inhaler |Types of Inhaler | Details on inhalers

Aerosol-Inhaler

In the inhaler, the gas is a suspension of solid or liquid droplets of drugs.

What is aerosol?

An aerosol is a suspension of microscopic solid particles or liquid droplets, in the air or other gases.

What is an inhaler?

An inhaler is a medical device used for delivering a specific quantity of drugs into the lungs. This is used for the treatment of asthma and pulmonary diseases.

The particle size distribution for most inhalation aerosols has been recognized as 1-5 µm in the range.

Types of inhalers

Basically, there are two types of inhalers available: Metered-Dose Inhalers (MDIs) and Dry Powder Inhalers (DPIs)

Tests for pharmaceutical aerosols depends on the analysis of so many parameters:

Particle size and shape distribution of the drug particles
Presence of foreign particles
Growth of crystal
Morphological changes of the drug substances.

Metered-Dose Inhalers (MDIs) :

The MDI device contains a canister (the cylinder)and an actuator (operator of the device), and sometimes a spacer. The canister is connected with a metering dose valve with the actuator. The formulation of the drug present in the canister is a liquefied gas propellant. Actuation of the device releases a single metered dose of liquid propellant that contains the drug formation. The microparticles/microdroplets are delivered into the lungs.

 

Dry Powder Inhalers (DPIs)

This is an alternate device of the MDIs. These types of inhalers are used to deliver a very fine dry powder particle of medicine to the lungs. The medicinal contents are released by taking a deep and fast breath in through the mouth space of the inhaler.