Prolonged oral transmucosal delivery of highly lipophilic drug cannabidiol.

Delivery of drugs through oral mucosa enables bypass of the gastrointestinal tract and "first pass" metabolism in the liver and the gut. Thus, a higher and less variable bioavailability can be obtained. Mechanisms of this administration route for cannabidiol were investigated in the current research in pigs. Results show that cannabidiol has substantially low permeability rate over 8 h through oral mucosa and accumulates significantly within it. Furthermore, following the removal of the delivery device, residual prolongation of release from the oral mucosa into systemic blood circulation continues for several hours. This method of delivery enabled acquisition of clinically relevant plasma levels of cannabidiol. The absorption profile indicates that cannabidiol, as well as other lipophilic molecules, should be delivered through oral mucosa for systemic absorption from a device that conceals the drug and prevents its washout by the saliva flow and subsequent ingestion into gastrointestinal tract.