The effect of carrier particle size on adhesion, content uniformity and inhalation performance of budesonide using dry powder inhalers

Dry Powder Inhalers (DPIs) are the result of the development of two technologies: powder
technology and device technology. Particle deposition in the respiratory tract is affected by
many aerosol particle properties such as particle size, shape, density, charge, and
hygroscopicity.1 In particular, particle size is of great importance as it is known that particleparticle
interactions within DPI formulations are related to van der Waals forces. Therefore,
particle size is the most important physical property and design variable of a DPI formulation.
Several studies were reported on the effect of drug particle size on DPI performance, showing
that the preferred drug particle size is between 1-5 μm.2 However, in literature, the effect of
carrier particle size distribution (PSD) on drug aerosolisation efficiency has received less
attention and reported in dissimilar manner.3 Nevertheless, it should be noted that there is rare
studies aimed to show the effect of carrier particle size as a single variable factor on DPI
performance. In this study, the effect of lactose particle size distribution on budesonide
adhesion, content uniformity and in vitro aerosolisation performance was investigated.