Copyright ERS Journals Ltd 1997 European Respiratory Journal

ABSTRACT: Drug delivery to patients using dry powder inhalers, such as the Turbuhaler®, is believed to be influenced by the inspiratory flow used. Clinical studies have indicated that this delivery system can be used effectively by child-ren. However, it is not known how the total and weight-corrected dose delivered to the airways varies with age. A deposition study using technetium-99m (99mTc)-label-led budesonide was performed in order to determine the effect of age on delivery. Twenty one children with cystic fibrosis, aged 4–16 yrs, were recruited. They were clinically stable with normal lung function. Initially, a gamma camera scan was taken in front of a flood source containing 37 MBq of 99mTc. Subsequently, subjects inhaled through a low resistance inspiratory filter connected to a com-mercially available Turbuhaler®. Immediately afterwards they inhaled from a noncommercial Turbuhaler ® containing budesonide labelled with 99mTc, and then underwent anterior and posterior gamma camera scans. Both Turbuhaler ® in-halers were attached to a portable spirometer and the peak inspiratory flow through the Turbuhaler ® was recorded for each inhalation. The total body dos