Dry powder inhalation (DPI) products basically consist of a powder formulation and a device. The formulation, which contains active pharmaceutical ingredient(s) (APIs) micronized to inhalable particle size and a few excipients may, at first glance, appear simple. However, a large number of factors are critical to the performance of dry powder formulations for inhalation. Furthermore, many of these interact in complex ways.
The articles in this two-part series will focus on adhesive mixtures for inhalation. The first article discusses considerations relating to the four parts that together define a dry powder formulation: the formulation, excipient, composition and processing. The author’s vision is that in-depth knowledge of the four parts that define a formulation and the ways they interact can lead to improved formulation development in the future.