Standardized inhalation capability assessment: A key to optimal inhaler selection for inhalation therapy.

Inhalation therapy has become one of the fundamental treatments for chronic obstructive pulmonary disease (COPD) and bronchial asthma (asthma). [1,2] Meanwhile, with the development of inhaled formulations and devices, inhalation therapy has shown a wide prospect of expanding indications, including respiratory diseases such as lower respiratory tract infections,[3] interstitial lung diseases, lung cancer,[4] as well as other diseases such as diabetes and depression.[5] Compared to oral and intravenous administration, the aerosolized drug is inhaled and acts directly on the airways and lungs, which has the advantages of rapid onset, sustained efficacy, and low systemic adverse effects.[6] Compared to the nebulizer, the hand-held inhaler is a better option for out-of-hospital drug delivery because the latter is easier to operate, requires shorter inhalation time, and has less environment extravasation.[6]