The blood-brain barrier that separates the brain interstitial fluid from the
circulating blood provides an efficient barrier for the diffusion of most drugs
from the blood to receptors in the central nervous system (CNS). This limits drug
treatment of CNS diseases, such as Parkinson's and Alzheimer's diseases. In recent
years, interest has been expressed in the use of the nasal route to deliver drugs
to the brain, exploiting the olfactory pathway.
Read about the clinical success
of ViaNase in nasally delivering insulin in Alzheimer's patients.