A team of neuroscientists and engineers has created a nasal spray to deliver schizophrenia medication directly to the brain instead of having it pass through the body. The study was conducted at McMaster University, Canada. 

According to the researchers, the leap in efficiency means patients with schizophrenia, bipolar disorder and other conditions could see their doses of powerful antipsychotic medications cut by as much as three quarters. The researchers explain that a problem for patients using antipsychotic medications is that taking them orally or by injection means the drugs must pass through the body before they reach the brain through the blood. To be sure enough oral or injected medication reaches the brain, a patient must take much more than the brain will ultimately receive, leading to sometimes serious adverse side effects, including weight gain, diabetes, drug-induced movement disorders and organ damage over the long term.

The new method delivers medication in a spray that reaches the brain directly through the nose, enabling the medication to enter the brain directly via the olfactory nerve.

“This way we can bypass the blood-brain barrier. By delivering the drug directly to the target, we can avoid side effects below the brain,” said Professor Rm Mishra, one of the authors of the study. 

The team had previously created a water-soluble form of the schizophrenia medication PAOPA.  The new form they created was easier to manipulate, but they still lacked an effective vehicle for getting it to the brain. A particular issue was that drugs delivered via the nose are typically cleared from the body quickly, requiring frequent re-administration.

The engineering side of the team was able to bind the drug to corn starch nanoparticles that, when sprayed together with a natural polymer derived from crabs, could penetrate deep into the nasal cavity and form a thin gel in the mucus lining, slowly releasing a controlled dose of the drug, which remains effective for treating schizophrenia symptoms over three days. The researchers proved the concept of their new delivery mechanism in rats.

“The corn starch nanoparticles we were using for an industrial application were the perfect vehicle,” said Professor Todd Hoare, one of the authors of the study. “They are naturally derived, they break down over time into simple sugars and we need to do very little chemistry on them to make this technology work, so they are great candidates for biological uses like this.”

The gradual release means patients would only need to take their medication every few days instead of every day or, in some cases, every few hours.

The study was published in Journal of Controlled Release.