Modelling of the spray drying process for particle design

• Published in: Chemical engineering research & design Vol. 132; pp. 1091 - 1104
• Main Authors: Cotabarren, Ivana M., Bertín, Diego, Razuc, Mariela, Ramírez-Rigo, M. Verónica, Piña, Juliana
• Format: Journal Article
• Language: English
• Published: Rugby Elsevier B.V 01-04-2018; Elsevier Science Ltd
• Subjects: Atomization; Chemicals; Chloride; Correlation analysis; Crystallization; Detergents; Drying agents; Empirical analysis; Inhalable particles; Innovations; Modelling; Moisture content; Nanoparticles; Nozzles; Process variables; Spray drying; Steady state models; Spray drying; Modelling; Atomization; Inhalable particles
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2018.01.012

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•A mathematical model for inhalable powder production in a spray dryer is developed.•Particle size and aerodynamic diameter are well predicted being very sensitive to droplet size.•Particle density values are predicted with errors smaller than 6.4%.•The highest error in the product temperature prediction is 12%.•Predictions of particle density could be improved by including intra-particle phenomena.
Spray drying is widely applied in many industries, such as the pharmaceutical, food, detergents, polymers, to convert liquids in solid particles. However, it still requires continuous innovation in order to provide more sophisticated particles, which are difficult to design by using only empirical approaches. In this context, a steady-state mathematical model for a co-current spray dryer is developed to give a more phenomenological insight in the production of inhalable particles. The model includes mass, energy and momentum balances for both particulate and gaseous phases. Particularly, and as a model inhalable compound, ciprofloxacin hydrochloride (CIP) aqueous solutions are studied. Several experimental data, obtained in a Mini-Spray Dryer B-290, BÜCHI, were available. In addition, droplet size measurements were carried out by using laser diffraction. The effect of the binary nozzle operating conditions on the mean droplet size was analyzed and a correlation to predict the mean Sauter diameter was established. The experimental data are used to fit and validate the proposed model. The validated model is used to perform parametric studies in order to evaluate the effect of the main process variables on the final product properties (e.g., particle size and density, powder moisture content) and to track key powder attributes for pulmonary administration.