Asthma and chronic obstructive pulmonary disease (COPD) patients are required to inhale forcefully and deeply to receive medication when using a dry powder inhaler (DPI). There is a clinical need to o
*FEV1, forced expiratory volume in 1 second; PEF, peak expiratory flow; histamine PC20, provocative concentration of histamine required to cause a 20% fall in FEV1, asthma exacerbation rates; JACQ, Ju
