Objectives: To compare the deposition patterns within the nasal cavity between the bi-directional and unilateral nasal delivery systems. And to summarize the clinical application of the bi-directional nasal drug delivery devices.
Data source: PubMed, Cochrane Library, Embase, and Web of Science databases.
Methods: A scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). We included studies exploring patterns and influencing factors of particle depositions within the nasal cavity among patients, healthy controls, and nose cast models using the bi-directional and unilateral nasal delivery system. The clinical application of the bi-directional delivery devices was also summarized.
Results: A total of 24 studies were included in this review. Bi-directional nasal delivery systems utilize forced exhalation to power the delivery of drugs to deeper areas of the nasal cavity and paranasal sinuses. Unilateral nasal delivery systems included traditional liquid spray pumps, the aerosol mask system, nebulization, and conventional nasal inhalation. Compared with unilateral delivery systems, the bi-directional nasal delivery system provided a more extensive and efficient nasal deposition in the nasal cavity, especially in the olfactory cleft, without lung deposition. Several parameters, including particle size, pulsatile flow, and nasal geometry, could significantly influence nasal deposition. The bi-directional nasal delivery system enables better delivery of steroids or sumatriptan to the sinonasal cavity's high and deep target sites. This bi-directional delivery device demonstrated an effective and well-tolerated treatment that produced high drug utilization, rapid absorption, and sustained symptom improvement among patients with chronic rhinosinusitis (CRS) or migraine.
Conclusion: The bi-directional nasal drug delivery systems demonstrated significantly higher drug deposition in superior and posterior regions of the nasal cavity than unilateral nasal delivery systems. Further studies should explore its potential role in delivering drugs to the olfactory cleft among patients with olfactory disorders and central nervous system diseases.
Level of evidence: N/A.
Keywords: bi‐directional delivery device; central nervous system; chronic rhinosinusitis; exhalation delivery system; nasal deposition; olfactory pathway; treatment.
© 2023 The Authors. Laryngoscope Investigative Otolaryngology published by Wiley Periodicals LLC on behalf of The Triological Society.