Chapter 3 Administration of Aerosolized agents

Aerosol

Suspension of liquid or solid particles between 0.001 and 100 micrometers (um) in diameter in a carrier gas

Stability

Describing the tendency of aerosol particles to remain in suspension

Penetration

Referring to the depth within the lung reached by particles

Deposition

Describing the process by which particles deposit out of suspension to remain in the lung

Particle size

a major factor in lung penetration by aerosols

Count mode

The most frequently occurring particle size in the

distribution.

Count median diameter (CMD)

The particle size above and below which 50% of the particles are found

mass median aerodynamic diameter (MMAD)

The particle size above and below which 50% of the mass of the particle is found

Geometric standard deviation (GSD)

- Measure of the dispersion of a distribution

- Calculated as the ratio of particle size below which 84% of the particles occur to the particle size below which 50% occur, in a log-normal distribution

Cascade impaction

Measures what is termed the aerodynamic diameter of aerosols because the measurement is based on the aerodynamic behavior of the particles in the cascade impactor

Laser

The instrument determines the relationship between the intensity and the angle of light scattered from a particle, then calculates the particle size based on the Mie-scattering theory