Abstract

The nasal passage is not only very narrow but also with a complex structure, which filters most nasally inhaled aerosols, preventing effective nose-to-brain drug delivery with a conventional method. Different methods have been tested to optimize targeted drug delivery to the olfactory mucosa, where deposited drugs can enter the brain. These include pointed drug release, bi-directional intranasal delivery, electromagnetic guidance, and pulsating flows. Both in vitro experiments and computational simulations were used to quantify the aerosol deposition rate to the olfactory region. Results showed that point drug release and the bi-directional technique both yielded improved but very small percentage of deposition in the olfactory region. Electric charge or magnetize aerosol particles can further improve olfactory targeting by applying an appropriate external electric or magnetic field in the nose. The olfactory deposition was sensitive to the voltage of the electrode close to the nose. For both the normal and bi-directional deliveries, electric field guidance resulted in a significant increase (3~5 times) in the olfactory deposition.

Keywords: Olfactory targeting; Personalized medicine; Electromagnetic steering; Nose-to-brain drug delivery