When it comes to brain diseases, pills are actually an extremely inefficient way to deliver drugs to the brain, and according to researchers spraying the patient's nose could be a more efficient way of releasing the drug where it is needed.
"People with brain diseases are often given huge amounts of unnecessary drugs. During a long life, or if you have a chronic disease, this may become problematic for your health," said Massimiliano Di Cagno, assistant professor at the Department of Physics, Chemistry and Pharmacy, University of Southern Denmark.
Cagno and his colleagues have turned their attention to the nose - specifically the nasal wall and the slimy mucosa that covers it.
"If the drugs cannot get out of their vehicles, they are no help to the patient. So we needed to develop a vehicle that does not lock the drug in," said Di Cagno.
The vehicles for drug delivery through the nose are typically made of so called polymers.
Massimiliano Di Cagno and his colleagues tested a natural sugar polymer and they said that this particular polymer is not only capable of carrying the drugs through the nasal wall but also - and most importantly - releasing the drug where it is needed.
"This is an important breakthrough, which will bring us closer to delivering brain drugs by nasal spray," said Di Cagno.
With this discovery two out of three major challenges in nasal delivery of brain drugs have been met.
"We have solved the problem of getting the drug through the nose, and we have solved the problem of getting the drug released once it has entered the brain.
"Now there is a third major challenge left: To secure a steady supply of drugs over a long period. This is especially important if you are a chronic patient and need drug delivery every hour or so," said Di Cagno.
When a patient sprays a solution with active drugs into his nose cavity, the solution will hit the nasal wall and wander from here through the nasal wall to the relevant places in the brain.
"But gravity also rules inside the nose cavity and therefore the spray solution will start to run down as soon as it has been sprayed up the nose. We need it to cling to the nasal wall for a long time, so we need to invent some kind of glue that will help the solution stick to the nasal wall and not run down and out of the nose within minutes," Di Cagno said.
The study was published in the International Journal of Pharmaceutics.