The Fundamental Role of Lipids in Polymeric Nanoparticles: Dermal Delivery and Anti-Inflammatory Activity of Cannabidiol.

This report presents a nanoparticulate platform for cannabidiol (CBD) for topical treatment of inflammatory conditions. We have previously shown that stabilizing lipids improve the encapsulation of CBD in ethyl cellulose nanoparticles. In this study, we examined CBD release, skin permeation, and the capability of lipid-stabilized nanoparticles (LSNs) to suppress the release of IL-6 and IL-8. The nanoparticles were stabilized with cetyl alcohol (CA), stearic acid (SA), lauric acid (LA), and an SA/LA eutectic combination (SALA). LSN size and concentration were measured and characterized by differential scanning calorimetry (DSC), in vitro release of loaded CBD, and skin permeability. IL-6 and IL-8 secretions from TNF-α-induced HaCaT cells were monitored following different LSN treatments. CBD released from the LSNs in dispersion at increasing concentrations of polysorbate 80 showed non-linear solubilization, which was explained by recurrent precipitation. A significant high release of CBD in a cell culture medium was shown from SALA-stabilized nanoparticles. Skin permeation was >30% lower from SA-stabilized nanoparticles compared to the other LSNs. Investigation of the CBD-loaded LSNs' effect on the release of IL-6 and IL-8 from TNF-α-induced HaCaT cells showed that nanoparticles stabilized with CA, LA, or SALA were similarly effective in suppressing cytokine release. The applicability of the CBD-loaded LSNs to treat topical inflammatory conditions has been supported by their dermal permeation and release inhibition of pro-inflammatory cytokines.