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.

Levels of sirolimus in saliva and blood following oral topical sustained-release varnish delivery system application.

PURPOSE: Sirolimus (rapamycin) is a mammalian target of rapamycin pathway blocker. The efficacy of sirolimus is currently studied for its antiproliferative properties in various malignancies and particularly in squamous cell carcinoma and other oral disorders. Topical application at the oral cavity can augment sirolimus availability at the site of action by increasing sirolimus levels in saliva and hence efficacy, along with improved safety (low levels in the blood to avoid side effects) and compliance. Our purpose was to evaluate the release profile and safety of a topical sirolimus sustained-release varnish drug delivery system. SUBJECTS AND METHODS: Sirolimus sustained-release varnish drug delivery system containing a total of 0.5 mg of the drug was applied to nine healthy male volunteers. Saliva and blood levels were determined utilizing mass spectrometry and chemiluminescent microparticle immunoassay, respectively. The prolonged release profile and safety were evaluated for the oral topical delivery system. RESULTS: After the application of the drug delivery system, a sustained-release profile was observed in the oral cavity. We have measured moderate sirolimus levels for up to 12 h. The safety was confirmed, and systemic sirolimus blood levels were negligible. CONCLUSIONS: After an application of sirolimus sustained-release varnish drug delivery system, prolonged drug levels can be achieved in the saliva. The oral topical sirolimus concentrations were potentially therapeutic along with minimal systemic exposure. These results broaden the potential clinical use of sustained-release oral topical rapalogs.