This review discusses how advances in formulation and device design can be utilized to dramatically improve lung targeting and dose consistency relative to current marketed dry powder inhalers (DPIs). Central to the review is the development of engineered particles that effectively bypass deposition in the upper respiratory tract (URT). This not only reduces the potential for off-target effects but it also reduces variability in dose delivery to the lungs resulting from anatomical differences in the soft tissue in the mouth and throat. Low-density porous particles are able to largely bypass URT deposition due to the fact that both the primary particles and their agglomerates are respirable. The low-density particles also exhibit dose delivery to the lungs that is largely independent of inspiratory flow rate across a range of flow rates that most subjects achieve with portable DPIs. Coupling this with delivery devices that are breath actuated, simple to operate (open-inhale-close), and have adherence-tracking capability enables drug delivery that is largely independent of how a subject inhales, with a user experience that is close to that of an "idealhaler."
Keywords: flow rate dependence; impaction parameter; particle image velocimetry; porous particles; total lung dose.