Learning Objective

• Basic components of an aerosol system

The basic components of an aerosol system are as follows:

1. Container
2. Valve and actuator
3. Concentrate containing the active ingredient(s)
4. Propellant

Characteristics such as particle size distribution, uniformity of dose (for metered valves), delivery rate, spray pattern and velocity, wetness, temperature of spray, fluid viscosity and foam density are determined by the nature of these components.

The propellant and the product concentrate will be discussed in detail in the section dealing with formulation of pharmaceutical aerosols.