|Impel NeuroPharma's Precision Olfactory Device--Courtesy of Impel|
A nasal spray could offer a new route by which to administer a peptide used to treat depression, as published in a new study by researchers at the Toronto, Canada-based Centre for Addiction and Mental Health (CAMH). It's the first time this type of delivery has been used to treat the condition.
Using nasal spray technology from U.S. company Impel NeuroPharma, CAMH's Fang Liu and her team of researchers demonstrated in rats that an interfering peptide designed to disrupt an interaction between dopamine receptors in the brain acted as an antidepressant when delivered across the nasal passage. Previously, the scientists showed that the drug worked the same way when injected directly into the brain, but this route of delivery was too invasive for clinical viability, they wrote in their study published in the journal Neuropsychopharmacology.
To treat major depressive disorder, which is associated with significant morbidity, Liu and team said, the peptide disrupts the interaction between the D1 and D2 dopamine receptors in the brain, a binding pathway that is notably higher in the brains of people with major depression. Delivered intranasally, the drug could be detected for two hours at a time, according to the abstract.
"Clinically, we needed to find a noninvasive, convenient method to deliver this peptide treatment," Liu said in a statement. "This study marks the first time a peptide treatment has been delivered through nasal passageways to treat depression."
Currently, many medications used to treat depression work by blocking serotonin or norepinephrine transporters and can be taken orally. But with a peptide such as this one, which could end up being more effective as a treatment, the oral route isn't an option, as it wouldn't cross the blood-brain barrier. So the nasal route is a necessity.
The researchers are working now to make the peptide break down more slowly and reach the brain more quickly as they continue with preclinical trials.