Multi-Scale Modelling of Powder Dispersion in a Carrier-Based Inhalation System
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Carrier-based dry powder inhalers (DPIs) are widely used for rapid and convenient delivery of drug to the site of action. This work aimed to predict powder aerosolisation in DPIs through numerical modelling.
A multi-scale modelling technique based on the combined computational fluid dynamics (CFD) and discrete element method (DEM) approach was developed.
The simulation results of the detachments of the drug particles from single carrier under different impact velocities and angles were comparable with those measured in the experiments in terms of fine particle fraction FPF loaded . Empirical equations were developed to link the detachment performance with impact velocity and impact angle. Then the dynamics of the carrier particles in Aerolizer® was simulated. The results indicated that the carrier-wall impaction was the dominant mechanism for drug aerosolisation performance. By linking the empirical equations with the carrier-wall impact energy, the predictions showed that for a given formulation mass with a fixed carrier/drug ratio, the inhaler performance decreased with carrier size and increased with air flow rate. Device empty efficiency, however, was independent with carrier size and flow rate.
The multi-scale model was able to provide quantitative information to better understand the aerosolisation mechanisms of carrier-based formulation.
KEY WORDScarrier-based formulation computational fluid dynamics discrete element method dry powder inhaler numerical modelling powder dispersion
ACKNOWLEDGMENTS AND DISCLOSURES
Authors are grateful to the Japan Society for the Promotion of Science (JSPS) and the Australia Research Council (ARC) for the financial support through the Discovery Project.
- 2.Clark AR. Pulmonary delivery technology: recent advances and potential for the new millennium. In: Hickey AJ, editor. Pharmaceutical Inhalation aerosol technology. New York: Marcel Dekker, Inc.; 2004. p. 571–91.Google Scholar
- 13.Dickhoff BHJ, De Boer AH, Lambregts D, Frijlink HW. The effect of carrier surface and bulk properties on drug particle detachment from crystalline lactose carrier particles during inhalation, as function of carrier payload and mixing time. Eur J Pharm Biopharm. 2003;56(2):291–302.CrossRefPubMedGoogle Scholar
- 24.Ganderton D, Kassem, N.M. DRY Powder inhalers: Advances in Pharmaceutical Sciences. London: Academic Press; 1992. P. 165–191.Google Scholar
- 32.Gidaspow D. Multiphase flow and fluidization. San Diego: Academic; 1994.Google Scholar