Experimental Study and Modeling of Dispersion in Spray Drying for Producing Powdered Pharmaceutical Compositions

The paper presents theoretical and experimental studies of spray drying technology for the production of dry powder pharmaceuticals for inhalation use. A numerical simulation of atomizing air flows in and around a pneumatic injector nozzle is presented and is then used to determine the key parameters of the atomizing process, namely, the atomizing air velocity relative to the liquid feed velocity. The range of permissible atomizing air velocities and the influence of this parameter on the size of the resulting particles are determined. Based on the obtained modeling results, a method for producing microparticles with an average size of 2.6 µm and a distribution from 1 to 4 µm is proposed.