Background: Many drugs are delivered intranasally for local or systemic effect, typically in the form
of droplets or aerosols. Due to the high cost of in vivo studies, drug developers and researchers often turn to in
vitro or in silico testing when first evaluating the behavior and properties of intranasal drug delivery devices
and formulations. Recent advances in manufacturing and computer technologies have allowed for increasingly
realistic and sophisticated in vitro and in silico reconstructions of the human nasal airways.
Objective: The study aims to perform a summary of advances in the understanding of intranasal drug delivery
based on recent in vitro and in silico studies.
Conclusion: The turbinates are a common target for local drug delivery applications, and while nasal sprays are
able to reach this region, there is currently no broad consensus across the in vitro and in silico literature concerning
optimal parameters for device design, formulation properties and patient technique which would maximize
turbinate deposition. Nebulizers can more easily target the turbinates, but come with the disadvantage of
significant lung deposition. Targeting of the olfactory region of the nasal cavity has been explored for the potential
treatment of central nervous system conditions. Conventional intranasal devices, such as nasal sprays
and nebulizers, deliver very little dose to the olfactory region. Recent progress in our understanding of intranasal
delivery will be useful in the development of the next generation of intranasal drug delivery devices.