Inhaler Testing

Emmace Consulting has an excellent knowledge in analyzing and evaluating inhalers, prototypes and exploratory formulations with standard and customized experimental methods. Emmace Consulting maintains specialized laboratories dedicated to inhaler performance testing, including advanced equipment for introducing patient realism into the test protocols. For particle sizing of the aerosol that leaves the inhaler device, we typically use full-resolution and abbreviated cascade impactors. We can also characterize some aerosols in real-time with laser diffraction, and we routinely measure plume geometry and spray pattern, delivered dose uniformity, and device air flow resistance.

All inhaler characterization studies are planned and designed in close collaboration with the client.

List of experimental analyses:

  • Delivered dose uniformity and aerodynamic particle size distribution assessment according to recognized global compendia, such as US Pharmacopeia section and European Pharmacopoeia sections 2.9.18 and 2.9.44
  • Particle size distribution analysis by laser diffraction. For DPIs, custom inhaler housings are constructed to guide the aerosol dose into the laser beam
  • Nebulizer characterization using breathing patterns and chilled impactors according to regulatory best practices
  • Plume geometry and spray pattern measurement with high-speed imaging using the Envision system from Oxford Lasers (Oxon, UK)
  • Fast characterization of the aerodynamic properties using the Aerodynamic Particle Sizer in combination with the dilutor Impactor Inlet (product 3321 and 3306, TSI Inc., Shoreview, MN, USA)
  • Measurement of pressure drop over the inhaler and the impactor stages
  • Evaluation of the dose emptying process, e.g. dose characteristics vs time
  • Characterization of nasal devices
  • Stability studies
  • Dosing (delivered dose and impactor testing) can be performed in different temperatures and relative humidity, e.g. in 40C/RH75.


Our outstanding scientific work is performed at the quality level appropriate to the stage of product development. Our Quality System documents how we maintain our instrumentation, handle samples, and validate all analytical methods. Additional procedures include people management, how we document raw data and how calculation software is validated. We always apply a base level of formal quality, in which we use applicable parts of GLP/GMP and applicable ICH guidelines, and we can readily adopt these standard methods to the quality requirements set up by our customers. Moreover, our personnel have substantial experience working in GMP-controlled lab environments, and our quality systems have been inspected successfully by demanding customers.


Emmace Consulting can also contribute on a consultancy basis, for example as part of a client project team, giving a second opinion or due diligence assessment of inhaler technology, writing study protocols, training inhaler testing personnel, writing method validation documentation, and more.

We are very flexible – don’t hesitate to contact us for a discussion.

Three pictures show the spray plumes from three different hair spray brand

These pictures show the spray plumes from three different hair spray brands, including the calculated plume angle.