Inspiratory flows and the aerosol cloud from dry powder inhalers

The relationship between the delivered dose, the fine particle fraction and the fine particle dose and the value of inspiratory flow generated by the patient is one of the most important features of dry powder inhalers (DPIs). It significantly affects the amount of pulmonary deposition of the inhaled drug and the clinical effect of the drug. The results of research evaluating these relationships for popular in Poland dry powder inhalers are presented. Flow-dependent, relatively flow-dependent and relatively flow-independent inhalers are demonstrated.