Paper Title
BRIDGING THE GAP: UNDERSTANDING INTRANASAL DRUG DEPOSITION IN ADULTS AND CHILDREN FOR ENHANCED MEDICATION DELIVERY AND SAFETY

Abstract
Abstract - Intranasal drug delivery is a highly effective and lessinvasive method for medication administration. However, a significant knowledge gap exists regarding drug deposition differences between adults and children due to the exclusion of children from clinical trials. As individuals age from infancy to adulthood, their airway anatomy and respiratory conditions change, altering the rate and pattern of inhaled particle deposition. In this study, drug particle deposition was compared in healthy males aged 37and 5 years. Nasal geometries have been constructed using CT-scan images, with each side of the nose considered a distinct nasal passage model.Particle trajectories and deposition were evaluated using the Lagrangian tracking approach, including drag, Saffman’s lift, the rmophoretic, and Brownian forces.Three flow rates (8.7, 15, and 30 L/min) and two flow regimes (laminar and turbulent) were utilized by the Steady-Laminar and Steady-kω-SST models.Deposition analysis in four regions of each nasal airway geometry (the vestibule, nasal valve, anterior turbinate, and nasopharynx) was determined for varying particle diameter (1–100 μm), spray cone angle (32º, 79º), and injection speed (2, 19.2 m/s).Simulation results of the inhalation pressure drop and particle deposition rate provided a reasonable match with existing experimental results. Much higher breathing resistance was observed in thechild. Deposition patterns were sensitive to particle diameters, injection speed, and half-cone angle. The knowledge gained from this study has significant implications for pharmaceutical drug development, clinical trial design, and personalized medicine, ultimately leading to safer and more effective therapeutic interventions for patients of all age groups. Keywords - Simulation, Drug Delivery, Personalized Medicine