Drug Delivery Systems Research Highlights Importance of Airway Wall Motion, Breathing Patterns, and Mucus Layer in Targeting Deep Lung Delivery

A recent study published in the Journal of Drug Delivery Science and Technology has shed light on the complexities of drug delivery systems, particularly in patient-specific airways, and the crucial role of airway wall motion, breathing patterns, and the mucus layer in targeting deep lung delivery. Researchers from Lakehead University, led by Leila Pakzad, constructed patient-specific airway models of individuals with chronic obstructive pulmonary disease (COPD) to investigate the impact of gender-based airway differences, dynamic wall deformation, and mucus presence on airflow and aerosol deposition from pressurized metered-dose inhalers (pMDIs).

Key Takeaways:

• The study found that the distinct geometry of the female airway induced higher airflow velocities and increased turbulence, resulting in a 43% rise in upper airway deposition compared to the male airway geometry.
• Under transient COPD flow rate, turbulence and upper airway deposition were reduced, thereby enhancing deep lung delivery by 16.35% in the male and 67.35% in the female airways.
• Dynamic airway motion lowered total deposition, but its impact was limited by the short injection time of pMDI, as most particles had already traversed the upper airway before peak wall displacement occurred.
• Mucus altered airflow dynamics and shear stress distribution, underscoring its crucial role in localized drug delivery, despite its minimal impact on overall deposition.
• The research concluded that patient-specific airway models are crucial for accurate aerosol deposition prediction and that gender-based differences in airway geometry play a significant role in drug delivery outcomes.

Statistics:

• 43% increase in upper airway deposition in the female airway compared to the male airway geometry.
• 16.35% enhancement in deep lung delivery in the male airways under transient COPD flow rate.
• 67.35% enhancement in deep lung delivery in the female airways under transient COPD flow rate.
• 43% rise in turbulence and upper airway deposition in the female airway due to its distinct geometry.

Sources:

• Research study: Experimental and Numerical Investigation of Drug Delivery In Patient-specific Male and Female Airways: Role of Airway Wall Motion, Breathing Patterns, and Mucus Layer, Journal of Drug Delivery Science and Technology, 2025; 113.
• Journal of Drug Delivery Science and Technology: Elsevier, Radarweg 29, 1043 Nx Amsterdam, Netherlands.
• Lakehead University: Dept. of Chemical Engineering, Thunder Bay, On, Canada.
• Research funding: Natural Sciences and Engineering Research Council of Canada (NSERC).