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Targeted Aerosol Delivery to NALT Using BiVax Intranasal Atomizer
27 Nov 2024
Nasal-associated lymphoid tissue (NALT), a crucial component of the mucosal immune system, is a well-organized network found in the pharyngeal and tubal tonsils of adults and children. Additionally, diffuse NALT is distributed in the superior, middle, and inferior turbinate regions of children. Despite its importance, effective methods for targeting NALT sites with aerosolized vaccines remain unclear. This study investigated whether head position, angle, and distance of device insertion could enhance the targeted delivery of fluorescein aerosol to NALT sites using three-dimensional models of intranasal airways.
By: Gonçalo Farias, Aptar Pharma Julie Suman, Aptar Pharma Jana Kesavan (Independent Researcher) Beth L. Laube (Independent Researcher) Mathilde Blondel, Aptar Pharma
Presenter(s): Nektaria Karavas (Director Business Development, Prescription Division)
27 Nov 2024
Methodology
Two 3D-printed models simulating the nasal airways of an 18-year-old (adult) and a 5-year-old (child) were used. The study evaluated three head positions—upright (Up), tilted back 45° (45), and supine (Su)—with two insertion angles (30° and 45°) and two distances (6 mm and 9 mm). Aerosols were delivered using the Aptar Pharma BiVax 200 µL intranasal atomizer, and fluorescein deposition was quantified in the anterior nose, superior turbinate (upper third), middle turbinate (middle third), and the combined inferior turbinate and nasopharynx (lower third).
Key Findings
- NALT Targeting Efficiency and Head Positions
- Supine position showed the highest deposition in the middle third (middle turbinate region).
- Upright position optimized lower third deposition (inferior turbinate and nasopharynx).
- Across all head positions, anterior nose deposition was higher in adults than in children, while middle third deposition was more pronounced in children.
- Impact of Model Age
- Deposition in the middle turbinate region was significantly higher in the 5-year-old model, suggesting enhanced vaccine delivery potential to this NALT site in younger populations.
- Adults showed greater deposition in the anterior nose, likely due to anatomical differences in nasal airways.
- Device Insertion Angles and Distances
- No significant differences were observed in deposition between the 30° and 45° insertion angles or the 6 mm and 9 mm distances.
Discussion
These findings highlight the influence of head position and age-specific anatomy on targeting NALT regions with aerosolized vaccines. The BiVax intranasal atomizer demonstrated the ability to achieve precise deposition in key NALT regions under specific conditions:
- Supine position for middle turbinate targeting.
- Upright position for inferior turbinate and nasopharynx targeting.
- Children under five years of age may exhibit enhanced deposition in the middle turbinate region, making them prime candidates for nasal vaccine strategies.
Conclusion
This study offers valuable insights into the optimization of intranasal vaccine delivery systems. The findings suggest that adjusting head position during administration can significantly enhance targeted delivery to NALT regions, particularly when using the BiVax intranasal atomizer. While the results underline promising approaches for improving mucosal immunization, in vivo testing is essential to validate these findings and advance clinical applications.
By leveraging the adaptability of targeted aerosol delivery and understanding age-specific nasal anatomy, this research paves the way for more effective vaccine strategies, particularly in pediatric populations.
