Effects of body temperature and human tracheobronchial tree architecture on the deposition of medicinal aerosol
D.V. Antonov1, D.A. Zhikhrov1, O.V. Nagatkina1,2
1National Research Tomsk Polytechnic University, Tomsk, Russia
2I.M. Sechenov First Moscow State Medical University, Moscow, Russia
Keywords: inhalation delivery, drug aerosol, heat and mass transfer, spatial modeling, deposition, airways, tracheobronchial tree
Abstract
Inhalation drug delivery is becoming crucial in the treatment of a wide range of conditions, including those not directly related to the respiratory system. The therapy effectiveness is determined by deposition - the drug deposited proportion in the target areas of the respiratory tract. Despite constant improvements in inhalation devices, drug deposition in the therapeutic target rarely exceeds 60%. This is due to the inhaler design features and the dispersed system physicochemical properties, as well as patient inhalation technique errors. Pathological changes in physiological barriers and the architecture of the tracheobronchial tree also have a critical impact on deposition, potentially significantly reducing it. Conversely, maximum deposition may be limited by imperfect delivery systems and the distribution of drug particles by size, velocity, and target areas of the respiratory tract. In this study, we propose a predictive model for managing aerosol flows in the airways, aimed at achieving maximum deposition, taking into account the individual anatomical and physiological characteristics of the patient (airway physiology and airway architecture). The mathematical apparatus for spatial modeling was developed in the COMSOL Multiphysics environment using the Heat Transfer, Fluid Flow, and Particle Tracing modules, as well as user-defined functions. It was found that increasing body temperature from 309.75 K to 312.15 K enhances aerosol evaporation, reducing their diameter and redistributing deposition between airway compartments. It was shown that airway architecture critically influences deposition asymmetry: for geometries with pronounced anatomical asymmetry, the difference in deposition between the right and left bronchus reaches 60-80%, while for symmetrical geometries it does not exceed 10%. The obtained results substantiate the need for personalization of inhalation therapy based on body temperature and individual anatomy of the patient, which opens up opportunities for increasing the effectiveness of the treatment of bronchopulmonary diseases.
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