Inhalers and other pulmonary delivery devices have been routinely characterized at the CFDRC Biofluids lab. The objectives of the experiments included measurement of

• Total delivered dose
• Respirable fraction (size distribution)
• Spray plume patternation and cone angle

The experimental set-up for these studies is shown to the right. An Andersen 8-stage cascade impactor is used for the size analysis. Interrogation of the spray plume with a planar laser sheet followed by image capture on a high-speed CCD camera is used for plume analysis.

Typical results obtained from these experiments regarding the size distribution and spray patternation are shown. The spray plume patternation and cone angle are inputs to computational studies of inhalers, while the delivered dose is used to validate the models. Together, these quantitative assessments (model + experiment) can be used to analyze and rank different products/designs.