Particle Engineering For Inhalation Drug Delivery

By Matthew Ferguson, Senior Principal Investigator

The development of therapies for pulmonary disease continues to be an expanding market in pharmaceutical research. Pulmonary illness rates are increasing and respiratory disease continues to be a leading cause of death and disability worldwide. The breadth of small-molecule and biological compounds requiring lung delivery is expanding, raising demand for inhalation therapies that are efficacious, robust, affordable, and compatible for use with dry-powder inhalers.

A key aspect to successful development of therapies to meet market demand is the manufacture of formulations with the product-quality attributes suitable for inhalation delivery. A wide range of particle engineering approaches is available but selection of which technology would be best for a given active pharmaceutical ingredient (API) can be challenging, requiring:

1. establishing the target product profile and intended delivery device (e.g., dry-powder inhalers);
2. evaluating API properties and conducting focused feasibility experiments; and
3. evaluating the risks associated with each candidate particle engineering approach.

By understanding the ways particle engineering approaches influence the attributes of the product, developers can be in the best position to accelerate clinical testing, commercial development, and patient treatment.

This summary presents an overview of particle engineering technologies and a case study in which two engineering approaches are compared:  spray drying (a “bottom-up” technology) and jet milling (a “top-down” technology). These two proven, scalable approaches are relatively simple and are often a good starting point to determine if a more complex technology is required for success.