Comparative in vivo lung delivery of hydrofluoroalkane-salbutamol formulation via metered-dose inhaler alone, with plastic spacer, or with cardboard tube
Sj. Fowler et al., Comparative in vivo lung delivery of hydrofluoroalkane-salbutamol formulation via metered-dose inhaler alone, with plastic spacer, or with cardboard tube, CHEST, 119(4), 2001, pp. 1018-1020
Citations number
10
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Study objective: To compare the lung delivery of chlorofluorocarbon-free sa
lbutamol via a pressurized metered-dose inhaler (pMDI) alone, a pMDI with a
small-volume plastic spacer, and a pMDI. with a cardboard tube.
Design: A randomized, single (investigator)-blind, three-way, crossover stu
dy.
Setting: The Asthma and Allergy Research Group, Ninewells Hospital, Univers
ity of Dundee, Dundee, Scotland, UK.
Participants: Twelve healthy volunteers aged 16 to 65 years.
Interventions: The subjects mere administered 400 mug of salbutamol via a p
MDI alone, via a pMDI plus a small-volume plastic spacer, or via a pMDI plu
s a cardboard tube.
Measurements and results: Blood samples for plasma salbutamol concentration
s were taken at 5 min, 10 min, and 20 min after inhalation, to measure lung
bioavailability as a surrogate for relative lung dose. The addition of the
plastic spacer resulted in a significantly higher maximal plasma salbutamo
l concentration (CMAX) and average plasma salbutamol concentration (CAV) th
an the pMDI used alone. This amounted to a 1.48-fold (32%) difference (95%
confidence interval [CI], 1.03 to 2.13) for CMAX and a 1.42-fold (30%) diff
erence (95% CI, 1.01 to 2.00) for Cav. There was no significant difference
in the CMAX or CAV comparing the addition of the cardboard tube with the pl
astic spacer or the pMDI alone.
Conclusions: Using a chlorofluorocarbon-free pMDI with a plastic spacer pro
duced statistically, but not biologically, significant greater lung deliver
y of salbutamol. if a spacer is required for reasons other than increasing
delivered lug dose, then the addition of a readily available cardboard tube
will fulfill many of the required functions with no expense to the patient
.