Related Experiment Video
Updated: Apr 23, 2026

Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System
Published on: April 6, 2017
The effect of actuator nozzle designs on the electrostatic charge generated in pressurised metered dose inhaler
Yang Chen1, Paul M Young, David F Fletcher
1Respiratory Technology, Woolcock Institute of Medical Research and Discipline of Pharmacology, Sydney Medical School,, The University of Sydney, Sydney,, NSW, 2037, Australia.
Purpose:
To investigate the influence of different actuator nozzle designs on aerosol electrostatic charges and aerosol performances for pressurised metered dose inhalers (pMDIs).
Methods:
Four actuator nozzle designs (flat, curved flat, cone and curved cone) were manufactured using insulating thermoplastics (PET and PTFE) and conducting metal (aluminium) materials. Aerosol electrostatic profiles of solution pMDI formulations containing propellant HFA 134a with different ethanol concentration and/or model drug beclomethasone dipropionate (BDP) were studied using a modified electrical low-pressure impactor (ELPI) for all actuator designs and materials. The mass of the deposited drug was analysed using high performance liquid chromatography (HPLC).
Results:
Both curved nozzle designs for insulating PET and PTFE actuators significantly influenced aerosol electrostatics and aerosol performance compared with conducting aluminium actuator, where reversed charge polarity and higher throat deposition were observed with pMDI formulation containing BDP. Results are likely due to the changes in plume geometry caused by the curved edge nozzle designs and the bipolar charging nature of insulating materials.
Conclusions:
This study demonstrated that actuator nozzle designs could significantly influence the electrostatic charges profiles and aerosol drug deposition pattern of pMDI aerosols, especially when using insulating thermoplastic materials where bipolar charging is more dominant.
Related Concept Videos
Inhaled Medications
Design Example: Flow Through a Fire Extinguisher
The key to understanding how the...
Asthma-IV: Diagnostic and Management
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
Pipe Flowrate Measurement: Problem Solving
Bernoulli's Principle: Applications
Entrainment devices use a high fluid speed to create low pressures and, thus, entrain one fluid into another. Some examples of these devices are given below:
Pipe Flowrate Measurement
The orifice meter is a simple,...

