An in vitro analysis of the output of salbutamol from different nebulizers

The objective of this study was to determine the particle size and mass out put of salbutamol from different nebulizers used under simulated breathing conditions. Seven nebulizer/compressor combinations were assessed. Each nebulizer was c harged with 5 mg salbutamol solution and connected to a breathing simulator operating at tidal volumes of 150 mt and 600 mt. Nebulizers were operated for 15 min. Salbutamol collected on the filters was measured by liquid chro matography. Aerosol particle size was determined separately by laser diffra ction. The Pari LC Star nebulizer delivered the most salbutamol at both tidal volu mes. The maximal output of the Medicaid Ventstream and Sidestream nebulizer s was two-thirds that of the LC Star, and they delivered less salbutamol th an the LC Star or LC Plus nebulizers. The Intersurgical Cirrus nebulizer de livered the least salbutamol at both tidal volumes, although there was only a small difference between the Cirrus and Ventstream or Sidestream nebuliz ers at 150 mt tidal volume. The LC Plus nebulizer produced larger particles , mass median diameter 5.3 mu m, compared with 3.6-4.0 mu m for the other n ebulizers. In conclusion, there were large differences in the delivery of salbutamol b etween the nebulizers studied, even between nebulizers of apparently the sa me class, and this should be borne in mind by regulatory authorities, clini cians and researchers.