AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Characterization of Spray Velocities from a Pressurized Metered-Dose Inhaler
ABUBAKER ALATRASH, Edgar Matida, Carleton University
Abstract Number: 692 Working Group: Health Related Aerosols
Abstract Pressurized metered dose inhalers (pMDIs) are normally used to deliver medication in the treatment of certain lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis among others, and may be used by several patients all over the world in part of their lives.
Phase Doppler Anemometry (PDA) is point-measurement laser technique that can be used to evaluate pMDI aerosol medication velocity and size as function of time. These measurements can be used to help improving the performance of the inhalers concerning medication delivery. Previous reports (Dunbar, 1996, Crosland et al., 2008) indicated that the pMDI spray deflects as much as 7 degrees downwards from its axis, before coming back to its centreline during actuation. In the present investigation, two inhalers from different pharmaceutical companies, using the same medication (salbutamol sulphate) are tested in order to verify previous spray deflection measurements using PDA.
Results of measurement at the pMDI centreline (25, 50, 75, 100, and 125 mm from the inhaler outlet) show that for both pMDI brands, the spray velocities were bimodal in time, with two velocity peaks, the first one occurring as the spray was leaving the mouthpiece, and the second (at the same location) around 60 ms later, with a drop in the velocity occurring in between the two peaks.
References
1. Dunbar CA: Experimental and theoretical investigation of the spray issued from a pressurised metered-dose inhaler. PhD thesis. University of Manchester. Manchester, England, 1996.
2. Crosland B.M: An experimental characterisation of the velocities of the spray issued from a pressurised metered-dose inhaler. MSc thesis. Carleton University. Ottawa, Canada, 2008.