Inhalation performance of pollen-shape carrier in dry powder formulation: Effect of size and surface morphology

In a previous study, pollen-shape drug carriers are compared with traditional carriers at different drug mixing ratios and flow rates. It is found that pollen-shape drug carriers can deliver large amount of drug particles and reduce drug losses especially at low flow rates and high drug mixing ratios. In this study, the effect of size and surface morphology of pollen-shape carriers on drug delivery performance is assessed. Pollen-shape carrier particles having various sizes and surface asperities are synthesized. Budesonide (Bd) is used as the model drug. The drug delivery performances of the pollen-shape carrier particles are investigated using an Andersen Cascade Impactor (ACI) equipped with a Rotahaler ^® at gas flow rates of 30 and 60 L/min. Three drug mixing ratios are considered. While an increase in the carrier particle size has a mild improvement on the ED, it significantly improves the FPF. A sparse surface asperity has negligible effect on the ED at low flow rates but it improves the FPF compared to a dense surface asperity under all experimental conditions.