Development of silica nanoparticle transdermal delivery systems for cannabidiol

There is a broad range of literature focused on Cannabis sativa but these clinical trials often feature dosages of unrefined plant products with an unknown mix of chemicals, or studies involve a combination of the two main components; cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC). When isolated, CBD is non-psychoactive with therapeutic potential in treating pain and inflammation, well-tolerated with few side effects. However, oral formulations are hampered by needing high doses to combat first-pass metabolism. It requires a more efficient route of distribution. Instead of a common oral route, this research focuses on designing a novel system for transdermal drug delivery through characterisation, stability and release measurements of CBD-encapsulated organosilica nanoparticles. A novel formulation of CBD-encapsulated nanoparticles at 15 wt% loading was casted with polyvinyl alcohol (PVA) to simulate a nanofiber mat, typical of pharmaceutical patch formulations. In degradation studies, CBD-encapsulated nanoparticles and PVA-casted mats stay stable up to 4 weeks in a storage environment of 40°C and 70% humidity. Release measurements using a dissolution bath demonstrated the ability of PVA-casted particles to enhance release of CBD by 35% in simulated sweat compared to oral media. Franz cell transdermal release corroborates previous data, the effect based on CBD-particle dispersion within the PVA-film.