Modeling the performance of carrier-based dry powder inhalation formulations: Where are we, and how to get there?

Development of carrier-based dry powder inhalation formulations follows till date empirical approaches. This is mainly underlain by numerousness of interplaying determinants of performance and complexity of involved interactions. Mathematical modeling helps elucidate such interactions and aids rational development of formulations. This article provides a critical overview of attempts made to model the performance of carrier-based dry powder inhalation formulations. The complex dependence of the performance on formulation properties is comprehensively discussed. A potential microstructure-based model is ultimately introduced.