Improved targeting of beclomethasone diproprionate (250 μg metered dose inhaler) to the lungs of asthmatics with the Spacehaler

The Spacehaler™(Evans Medical Ltd, Leatherhead, U.K.) is a new, compact, inhaler device containing the same aerosol canister as a conventional metered dose inhaler (MDI). However, the design of the Spacehaler™has been shown to reduce the velocity of the aerosol, thus reducing the proportion of non-respirable particles delivered to the patient. This study compared radioaerosol deposition patterns following inhalation of 250μg of beclomethasone dipropionate from the Spacehaler™and a conventional MDI (Beclazone™, Norton Health Care, Harlow, U.K.). After rigorous in vitro validation of the radiolabelling technique, 12 asthmatic subjects (seven men aged 20–69 years, mean baseline FEV12·59l (sd 0·55l) received one dose of99mTc-labelled beclomethasone dipropionate 250μg via either a Spacehaler™or MDI on each of two study days in a randomized cross-over manner. All subjects had been taught the required inhalation technique before the dose was administered. Inhalation details were recorded using a spirometer connected in series with the device. Lung and oropharyngeal depositions were measured by gamma scintigraphy. The mean percentage of the metered dose deposited in the lungs was 23·0% (sd 8·3%) for the Spacehaler™and 12·8% (sd 6·8%) for the MDI (P