A semi-empirical model of aerosol deposition in the human respiratory tract for mouth inhalation.

A mathematical model for regional deposition of aerosols following inhalations via mouth has been developed. The model is in the form of algebraic equations which make it particularly efficient for computation of deposition of polydisperse aerosols. The parameters of the model were derived from average experimental data for "head' and tracheobronchial deposition which were supplemented by results of previous theoretical calculations and mass balance considerations. An example is presented to illustrate an application of the model to a problem in formulation of inhalation aerosols. To make the calculations more reliable for particular patho-physiological groups of patients, some modifications of the parameters used in the model are necessary. The model may be suitable, e.g. for testing the changes in regional deposition which would be likely to result from modification of particle size and related formulation properties of inhalation aerosols.