Analytical Technologies Singapore

Together with delivered dose, aerodynamic particle size distribution (APSD) is typically identified as a Critical Quality Attribute (CQA) for orally inhaled and nasal drug products (OINDPs) making it a primary focus for in vitro characterisation. 

The APSD of an OINDP defines how particles behave in a moving air stream. It is intuitively relevant to the understanding of likely lung deposition and hence potential drug efficacy. 

For devices such as nebulisers, the evaporation of droplets exacerbated by the thermal mass of the impactor can be a problem, especially for drugs in solution.

Typically particles should be in the range of 1 to 5 microns to be effective, any larger than 5 microns and they are likely to impact the oropharynx and be swallowed, any smaller than 1 micron and it is possible that the particles will remain entrained in the air system.

APSD of MDIs, DPIs & ADIs

Next Generation Impactor (NGI)

Manual Test Component Parts

Andersen Cascade Impactor (ACI)

Precision device for particle size distribution measurements

Multi Stage Liquid Impinger (MSLI)

Designed for the meticulous collection of airborne particles

Glass Twin Impinger (GTI)

A sampling device commonly used in air pollution studies to collect and analyse the chemical composition of airborne particles

APSD of Nebulisers

Nebuliser

Minimal evaporation of droplets exacerbated by the thermal mass of the impactor

APSD of Nasal Products

Next Generation Impactor (NGI)

APSD for
Nasal Spray, Nasal Aerosol,
Nasal Powder

Andersen Cascade Impactor (ACI)

APSD for
Nasal Spray, Nasal Aerosol,
Nasal Powder

Glass Twin Impinger (GTI)

APSD for Nasal Spray