In Vitro Effect of Flow Velocity on Aerodynamic Parameters of a Cromospir Metered Dose Inhaler

Abstract

The effect of changing flow velocity on the aerodynamic particle size distribution of Cromospir metered dose inhaler (MDI) was studied using an Andersen cascade impactor (ACI) in the standard configuration designed for sampling at flow velocity 28.3 L/min and in a modified configuration at 60 L/min. The aerodynamic particle size distribution and the respirable fraction of the aerosol changed if the flow velocity of air passing through the impactor changed. Studies of the aerodynamic properties of aerosols with patient inhalation modeled at various air flow rates are recommended during quality assessment method development for aerosols and for in vitro comparisons of MDI efficiencies.