Lung deposition of 5 mg Intal from a pressurised metered dose inhaler assessed by radiotracer technique

Abstract Deposition from a pressurised metered dose inhaler (MDI) delivering 5 mg sodium cromoglycate (Intal 5, Fisons plc), has been measured by a Tc99m-labelling technique Ten healthy volunteers inhaled (i) from a standard MDI at 30 l/min, (11) from a 10 cm spacer tube (Aerotube) at 30 l/min, and (111) from the Aerotube at 100 l/min A mean (SE) 8.8(11) % of the dose was deposited in the lungs from the standard MDI, but this amount was not significantly changed either for slow inhalation (11.3(1.9) %) or fast inhalation (7.1(1.3) %) through the spacer Lung deposition was lower than that observed previously for other cantsters delivering smaller amounts of drug per metered dose Oropharyngeal deposition fell from a mean 79% with standard MDI to a mean 29% with the spacer ( P