Particle size of beclomethasone dipropionate produced by two nebulisers and two spacing devices.

An impactor method was used to assess the amount of beclomethasone dipropionate in particles less than 5 microns produced by two nebulisers (Pari Inhalierboy, Medix Traveller compressor with cirrhus nebuliser chamber) and two spacer devices (Volumatic and Nebuhaler). After nebulisation of 3 ml (150 micrograms) beclomethasone dipropionate the amount of drug in particles less than 5 microns was 16 micrograms (GSD 1.1) with the Pari Inhalierboy, and 27 micrograms (1.4) with the Medix Traveller with cirrhus nebuliser. This was less than the amount in particles less than 5 microns after three metered dose inhaler actuations (150 micrograms) from the Nebuhaler (58.2 (1) micrograms) or the Volumatic spacer (46.5 (1) micrograms). The greater amount of beclomethasone dipropionate in small particles with administration from a metered dose inhaler with a spacer device means that considerably more drug is likely to reach the airways than when the same dose is given by the two nebulisers studied.