In Vivo Performance Testing of the Novel Medspray ® Wet Aerosol Inhaler

Abstract

Abstract

Background:

Monodisperse salbutamol inhalers were compared to select the optimal mass median aerodynamic diameter: 4.0, 5.0 or 6.0 μm.

Methods

: Fifteen mild asthmatic patients participated. In all a FEV₁-response of >12% (vs. baseline) or >200 mL after inhalation of 200 μg salbutamol was measured. Each patient was studied four times with intervals of 1 week (three active and one placebo inhaler). First, 10 μg salbutamol was administered, followed by 10, 20, and 40 μg, resulting in cumulative doses of 10, 20, 40, and 80 μg salbutamol. The FEV₁ and other lung function parameters were assessed at baseline and 30 min after inhalation of each consecutive dose. Five minutes later a next inhalation was given.

Results

: The 4.0- and 5.0-μm droplets did not differ from placebo (p = 0.502, p = 0.127), but the 6.0-μm droplets differed significantly (p = 0.003). The difference between 6.0–4.0 μm droplets was significant (p = 0.020), but not between the 6.0–5.0 μm droplets (p = 0.129). The FEV₁ increase after 80-μg salbutamol for the 6.0-μm droplets was 243 ± 144 mL.

Conclusions

: The study showed that the 6.0-μm droplets differed from the others in terms of FEV₁-improvement, and hence, are the most efficacious of the three evaluated.