What are the advantages of capsule-based DPI systems?

From a technical point of view, DPI devices offer many advantages: they are operable at low inhalation flow rates, deliver a uniform dose, and have a reduced environnemental impact versus other systems.
From a patient perspective, capsule-based DPI systems have several advantages such as portability, ease-of-use and, more importantly, patients can confirm that they have successfully taken their medicine by checking that the capsule is empty. Moreover, a capsule-based system is a simple and cost-effective solution.