New nasal spray could ease side-effects of antipsychotics, researchers say
The spray, partly developed by McMaster professors, delivers antipsychotic drugs directly to the brain
A nasal spray, and a little bit of corn starch: that’s the gist of a new product which could revolutionize the way psychotic disorders are treated.
Researchers at McMaster University teamed up over the past three years to develop the spray, which delivers antipsychotic medication straight to the brain. When taken orally or by injection, such medication lingers in the body, often causing significant side-effects.
Ram Mishra, one of two professors who led the research, said the spray could also cut the dosage of medication used to treat conditions such as schizophrenia and bipolar disorder by as much as three-quarters.
“It has a great significance because we can avoid the serious side-effects of antipsychotic medication, which can cause diabetes, heart problems, obesity and organ damage,” said Mishra, a professor of psychiatry and behavioural neurosciences and co-director of McMaster’s biomedical engineering program.
Mishra said antipsychotic medication is generally prescribed at higher doses to ensure the drug reaches the brain after a long trip through the circulatory system.
The nasal spray bypasses the blood-brain barrier to bring the drug directly to its target.
Using a mixture of drugs dissolved in water, it proved successful in a recent study conducted on rats. The issue for Mishra was getting the solution to the brain — and having it stay there.
That’s where Todd Hoare came in. He’s a professor of chemical engineering at McMaster who used microscopic nanoparticles of corn starch to trap the drug in a thin gel that courses through the nose and into the brain.
Drugs delivered through the nasal cavity, while effective, can clear quickly and require frequent respraying. But the nanoparticles of corn starch, when sprayed together with a natural polymer derived from crabs, penetrate deep into the nasal cavity and stick to the mucus lining of the nose.
“Then, the bonds that hold the gel together fall apart in water over time and those small starch particles start to get released,” said Hoare, adding it took hundreds of trials to get the mixture just right. “They’re able to transport through the nose and the nerve on the other side and up into the brain directly.”
The gel is trapped in the nose for about a week before clearing, and the drug continues to release into the brain for at least three days. It means patients only have to take medication every few days instead of daily.
Mishra said the early success of the nasal spray makes him optimistic for human clinical trials, which will go ahead after discussions with pharmaceutical companies and corporate partners wrap up.
“It’s an excellent start,” he said.