Important properties of nebulizers for aerosol particle therapy are the water and solute output, and the initial particle size distribution. These properties have to be determined experimentally. The evaporation of the particles during transport is estimated to be less than 10% in most cases. The changes in particle size during inhalation, and particle deposition, are estimated with a hygroscopic particle lung deposition model. The regional deposition of aerosol particles of an arbitrary material and an arbitrary size distribution can now be estimated. This method is applied to two jet nebulizers (Pari Inhalierboy and Wiesbadener Doppelinhalator), and to an ultrasonic nebulizer (DeVilbiss 65).