In silico optimization of targeted aerosol delivery in upper airways via Inhaled Volume Tracking

Despite the widespread use of aerosol inhalation as a drug delivery method, targeted delivery to the upper airways remains an ongoing challenge in the quest for improved clinical response in respiratory disease.

Here, we examine in silico flow and particle dynamics when using an oral Inhaled Volume Tracking manoeuvre. A short pulsed aerosol bolus is injected during slow inhalation flow rates followed by clean air, and a breath-hold is initiated once it reaches the desired depth. We explore the fate of a broad particle size range (1-40 microm) for both upright and supine positions.

Our findings illustrate that despite attempts to mitigate dispersion using slower flow rates, the laryngeal jet disperses the aerosol bolus and thus remains a hurdle for efficient targeted delivery. Nevertheless, we show a decrease in extra-thoracic deposition; large aerosols in the range of 10-30 microm potentially outperform existing inhalation methods, showing deposition fractions of up to 80% in an upright orientation.

The improved deposition during Inhaled Volume Tracking shows promise for clinical applications and could be leveraged to deliver larger payloads to the upper airways.