In this review, an extensive analysis of dry powder inhalers (DPIs) is offered, focusing
on their characteristics, formulation, stability, and manufacturing. The advantages
of pulmonary delivery were investigated, as well as the significance of the particle
size in drug deposition. The preparation of DPI formulations was also comprehensively
explored, including physico-chemical characterization of powders, powder processing
techniques, and formulation considerations. In addition to manufacturing procedures,
testing methods were also discussed, providing insights into the development and evaluation
of DPI formulations. This review also explores the design basics and critical attributes
specific to DPIs, highlighting the significance of their optimization to achieve an
effective inhalation therapy. Additionally, the morphology and stability of 3 DPI
capsules (Spiriva, Braltus, and Onbrez) were investigated, offering valuable insights
into the properties of these formulations. Altogether, these findings contribute to
a deeper understanding of DPIs and their development, performance, and optimization
of inhalation dosage forms.
