Journal of Medical Sciences1682-44741812-5727Asian Network for Scientific Information10.3923/jms.2004.63.69FeddahMajid R. DaviesNeal M. 1200441Rapid and reliable in vitro methods of analysis of aerosol particles are required in product development to ensure product safety and to attain process control quality to establish reproducibility of inhalation aerosols. The particle size distribution for beclomethasone dipropionate delivered from Becotide® and Respocort® inhalers was estimated using an Andersen Cascade Impactor and a scanning electron microscope coupled with an automated image analysis technique. The particle area and the volume-weighted distribution were estimated and compared to the volume-weighted distribution generated using a laser diffraction technique. No significant differences in the measurement of the particle size distributions using either area or the volume-weighted distributions for the small particles were evident. An alternative optical sizing method is described to evaluate particle size distribution and morphology of aerosols administered in metered dose inhalers using a cascade impactor and a scanning electron microscope. This method can directly measure particle size and also permits observation of the particle and surface texture of the particles under investigation.]]>Dolovich, M.,19914251263Marple, V.A. and B.A. Olson,199522124134Clark, T.J.H.,198576330334Hallworth, G.W. and R.P. Hamilton,197628890897Feddah, M.R., Brown, K.F. Gipps, E.M. Davies and N.M.2000In vitro characterization of metered dose inhaler versus dry powder inhaler glucocorticoid products: Influence of inspiratory flow rates.]]>3318324Feddah, M.R. and N.M. Davies,20035510551061Davies, N.M. and M.R. Feddah,2003255175187Laroye, G.J. and K. Grant,19941757083Steckel, H. and B.W. Muller,19981732533Low, B.W. and F.M. Richards,19527416601666Rance, RW.,197425545555Byron, P.R.,1987114243McCrone, W.C. and J.G. Delly,19732nd Edn.,