Variability in Nose-to-Lung Aerosol Delivery

Area of Science:

• Pulmonary Drug Delivery
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Nasal delivery of pharmaceutical aerosols via high flow nasal cannula (HFNC) is crucial for specific drug administrations.
• Previous studies indicate high aerosol losses and variability in nasal delivery systems and the nasal cavity.

Purpose of the Study:

• To assess aerosol delivery variability to the lungs using a nasal cannula interface.
• To compare conventional aerosol delivery with excipient enhanced growth (EEG) techniques.

Main Methods:

• Utilized computational fluid dynamics (CFD) validated with in vitro data.
• Modeled aerosol delivery through a nasal cannula in four adult nasal cavity CT scan-derived models.
• Simulated solid particles (0.9 and 1.5 μm) for EEG and conventional droplets (5 μm) at 30 L/min.

Main Results:

• EEG reduced nasal depositional losses by an order of magnitude and decreased variability.
• EEG improved the aerosol penetration fraction (PF) by approximately fourfold compared to conventional methods.
• Variability in PF (coefficient of variation) was reduced by fourfold with EEG delivery.

Conclusions:

• The EEG technique substantially improves lung aerosol delivery efficiency.
• EEG largely eliminates variability in nasal depositional loss and lung penetration fraction.
• EEG offers a more consistent and effective method for nasal aerosol delivery during HFNC therapy.