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Lung delivery of non‐CFC salbutamol via small volume metal spacer and large volume plastic spacer devices compared with an open vent jet nebulizer
Author(s) -
Lipworth B. J.,
Clark D. J.
Publication year - 1998
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1046/j.1365-2125.1998.00648.x
Subject(s) - nebulizer , salbutamol , volume (thermodynamics) , jet (fluid) , lung volumes , materials science , biomedical engineering , lung , medicine , anesthesia , aerospace engineering , engineering , physics , asthma , quantum mechanics
Aims To compare the lung delivery of salbutamol from a commonly used constant output open vent jet nebuliser (Sidestream) with use of both a conventional large volume plastic spacer (Volumatic) and a novel small volume metal spacer (NebuChamber). This was assessed using the early lung absorption profile of salbutamol over the first 20 min after inhalation.Methods Twelve healthy volunteers were studied in a randomized single (investigator) blind crossover design. Single 1200 μg nominal doses salbutamol from a CFC‐free metered‐dose inhaler (12 sequential 100 μg puffs of Airomir) were delivered via the Volumatic and NebuChamber spacers. A single 1200 μg nominal dose of salbutamol was given as a 4ml fill volume from a Sidestream nebuliser with mouthpiece. Mouth rinsing was performed after each drug sequence. Plasma salbutamol was measured at 5, 10, 15 and 20 min after the last dose of each inhalation sequence, with calculation of maximal concentration ( C max ) and average concentration over 20 min ( C av ). Systemic β 2 ‐responses were measured as plasma potassium, tremor and heart rate.Results Both the Volumatic and the NebuChamber spacers produced significantly greater salbutamol concentration than the Sidestream nebuliser. For C av this amounted to a 7.34‐fold difference (95%CI 5.31 to 9.38) between Volumatic vs Sidestream, and a 7.04‐fold difference (95%CI 4.91 to 9.17) for NebuChamber vs Sidestream. Similar differences were found for the extrapulmonary β 2 ‐responses. There were no significant differences in either salbutamol concentration or extrapulmonary β 2 ‐responses between the Volumatic and NebuChamber spacers.Conclusions We found that, in vivo , both the Volumatic and the NebuChamber spacers produced seven‐fold greater lung delivery of salbutamol than the Sidestream nebuliser when comparing microgram equivalent nominal doses, in terms of the early lung absorption profile.