Impact of Nasal Delivery Devices on Olfactory Drug Deposition

Nasal delivery offers a promising non-invasive approach for targeting therapeutics to the brain through the olfactory region. However, conventional nasal administration frequently produces predominant deposition in the anterior nasal cavity, limiting drug access to the olfactory epithelium. Nasal delivery devices play a critical role in overcoming these anatomical and aerodynamic barriers by controlling spray velocity, droplet or particle size, plume geometry, airflow, dose volume and administration direction. This review examines the impact of conventional and advanced nasal delivery devices on olfactory drug deposition, with particular emphasis on metered-dose sprays, nasal drops, nebulizers, powder devices, atomizers, breath-powered bidirectional systems and specialized nose-to-brain platforms. The influence of device design and administration parameters on regional deposition, mucosal retention and potential nose-to-brain transport is discussed. Computational fluid dynamics, nasal cast models, imaging techniques and experimental approaches used for deposition assessment are also reviewed. Emerging personalized and digitally optimized devices may provide improved and reproducible olfactory targeting for future CNS therapeutics. Keywords: Olfactory deposition, nasal delivery devices, nose-to-brain delivery, intranasal drug delivery, olfactory targeting