Formulation Methods & Size Reduction for Inhalers

Dry powder inhalers, or DPIs, are the most common type of medical inhaler produced. They are commonly used as a part of treatment for asthma, bronchitis, emphysema, COPD, and other diseases that affect breathing and the lungs. The powder that goes into DPIs have to be produce in a very specific way, especially since the particle sizes are usually only between 1 µm and 5 µm. However, Hosokawa Micron Powder Systems, and Hosokawa Alpine have the ability to process and create the powders that go into these inhalers. There are three ingredients that typically go into DPIs. They are:

Active Pharmaceutical Ingredients

The active pharmaceutical ingredient, or API, is the main ingredient that does most of the medical work. It is the essential ingredient in the inhaler. APIs are best processed using the Fluidized Bed Opposed Jet Mill or the Spiral Jet Mill. This is because these mills have the capacity to ensure that the particles that are ground are the required size of 1 µm to 5 µm. This also ensures that the particles are processed in a clean and hygienic environment, which is very important when processing pharmaceutical products.

The Carrier

The carrier is the ingredient that the API attaches to so that it can be carried and propelled far enough into the lungs to be of use. This is best processed through Jet Mills, Impact Mills, and Classifier Mills. This is because the carrier is typically courser than the API, and therefore does not need to be ground as finely. Classifiers help to ensure that the carrier particles do not exceed the maximum coarseness. Otherwise, the particles may be too coarse, and they will not travel to the lungs efficiently.


Additives are extra chemicals that assist in various functions of the inhaler, such as steroids, force-control agents, and various inter-particle agents. Once an additive is created, it has to be mixed in with the carrier and API. For this, we use a high shear mixer. High shear mixers effectively and hygienically mix these particles together, resulting in your finalized dry powder inhaler formula.

If you want to know more about the creation of powders for dry powder inhalers, and the application Hosokawa Micron Powder Systems can provide for doing so, watch this full-length webinar.