Aerosols

Pharmacist Ghada Hamid

Aerosols
They are pressurized dosage forms that upon actuation emit a fine dispersion of a liquid and/or solid materials containing one or more active ingredients in a gaseous medium.

Consideration required in aerosols:
1. Proper function of the container and valve assembly.
2. The propellant.
3. Physical delivery of the medication in proper form.

Aerosol products may be designed to expel their contents as a fine mist, a coarse wet or dry spray, a steady stream or a stable or fast breaking foam.
The physical form of aerosol is depend on the intended use:
• For inhalation therapy (like in treatment of asthma or emphysema) the product must be fine liquid mist or as finely divided solid particles (< 6µm for respiratory bronchioles) and (< 2µm reach alveolar ducts and alveoli).
• For dermatological purpose the particle size is coarser and less critical in therapeutic efficacy.

Space sprays: are aerosols used to provide an airborne mist, the particle size of the released product quite small below 50 µm.
Surface sprays: are aerosols which are intended to carry the active ingredients to a surface such as to the skin.