Numerical and Experimental Analysis of Drug Inhalation in Realistic Human Upper Airway Model

Area of Science:

• Biomedical Engineering
• Pharmaceutical Sciences
• Computational Fluid Dynamics

Background:

• Intranasal drug delivery requires efficient and targeted methods.
• Complex nasal geometry and measurement limitations necessitate numerical modeling for simulating airflow and aerosol dispersion.

Purpose of the Study:

• To investigate airflow, aerosol dispersion, and deposition patterns in a realistic nasal airway model.
• To assess the impact of varying inhalation flow rates and aerosol sizes on drug delivery efficiency.

Main Methods:

• Reconstruction of a CT-based, 3D-printed nasal airway model.
• Simulation of airflow pressure, velocity, turbulent kinetic energy (TKE), and aerosol deposition using laminar and SST viscous models.
• Comparison and verification of simulation results with experimental data.

Main Results:

• Negligible pressure drop in the nasal vestibule to nasopharynx at lower flow rates (5-15 L/min), with significant drops at higher rates (30-45 L/min).
• Substantial pressure reduction (approx. 70%) from the nasopharynx to the trachea.
• Aerosol deposition patterns varied significantly with particle size; over 90% of larger particles deposited in the anterior region, while less than 20% of ultrafine particles did.

Conclusions:

• Numerical modeling provides valuable insights into intranasal drug delivery dynamics.
• Particle size is a critical factor influencing deposition patterns and drug delivery efficiency in the nasal cavity.
• Ultrafine particles exhibit unique deposition characteristics, necessitating tailored delivery strategies.