Numerical evaluation of spray position for improved nasal drug delivery

TL;DR

This study introduces a new nasal spray technique that significantly improves drug delivery efficiency by leveraging inertial particle motion, validated through computational simulations and experimental measurements.

Contribution

It proposes a novel, user-friendly nasal spray usage strategy based on computational fluid dynamics, enhancing drug delivery in humans.

Findings

8-fold increase in drug delivery at target sites

Validated simulation results with in vitro gamma scintigraphy

Potential to change nasal spray usage guidelines

Abstract

Topical intra-nasal sprays are amongst the most commonly prescribed therapeutic options for sinonasal diseases in humans. However, inconsistency and ambiguity in instructions show a lack of definitive knowledge on best spray use techniques. In this study, we have identified a new usage strategy for nasal sprays available over-the-counter, that registers an average 8-fold improvement in topical delivery of drugs at diseased sites, when compared to prevalent spray techniques. The protocol involves re-orienting the spray axis to harness inertial motion of particulates and has been developed using computational fluid dynamics simulations of respiratory airflow and droplet transport in medical imaging-based digital models. Simulated dose in representative models is validated through in vitro spray measurements in 3D-printed anatomic replicas using the gamma scintigraphy technique. This work breaks new ground in proposing an alternative user-friendly strategy that can significantly enhance topical delivery inside human nose. While these findings can eventually translate into personalized spray usage instructions and hence merit a change in nasal standard-of-care, this study also demonstrates how relatively simple engineering analysis tools can revolutionize everyday healthcare.