Particle Engineering for Improved Pulmonary Drug Delivery Through Dry Powder Inhalers

The performance of a pharmaceutical powder aerosol is mainly dependent on aerosol physicochemical properties (e.g., size, shape and surface texture), solid state, water content and surface energy. Any subtle change in any of these properties may induce a drastic change in the bioavailability of a drug formulated within such a powder. Therefore, it is critical to have a full understanding of physical properties of bulk powder drug, carriers, and their blends to increase drug effectiveness, consistency and uniformity of the delivery system. Such studies should be performed at molecular level (chemical structure), particulate level (analysis of small number of particles) and bulk level (large assembles of particles). Failure to study some of the physical properties of the materials may be one of the most important causes of the lack of understanding of particle dispersal processes, the prediction of product performance, batch to batch variations and particle interactions, in dry powder inhaler (DPI) formulations. The role of particle engineering in designing smart particles is reviewed with a view to improving the aerosolization performance of drugs delivered from DPIs. Aerosolized engineered particles conferred a number of advantages such as better flowability, high homogeneity and high fine particle fraction when compared to untreated particles