Respiron Consulting has the capabilities to perform investigations of the particle size distribution of inhalation products. This is performed by using laser diffraction methodology. Typical applications are evolving aerosol plumes from a dry powder inhaler or the produced wet aerosol exiting a nebulizer. In the graphs below two  typical example the assesment of the droplet size distribution of an aqueous inhaler is seen. Note the larger droplets on the right hand of the graph on the left.

Figure 1

Liquid Iinhaler

In the above Figure a mean time average  droplet size distribution of a liquid inhaler actuation is seen. Two distributions peaks is seen, one around 5 um and one above 200 um. Its important to understand if the large peak is an artefact or not. To investigate this further an incremental time resolution of the actuation was performed, see the Figure on the right hand side.

Figure 2

Liquid inhaler Fig.2

The same liquid inhaler droplet size distribution was assessed using 25 individual measurements of incremental 50 ms time steps. The total time period thu equalling  1,25 seconds. From the Figure it was concluded that in the end of the actuation the droplet size increased thereby causing the large droplet size distribution seen in the Figure on the left.