Solid Pro-Nano Lipid Oral Formulations for Cannabidiol (CBD)

Background: Solid pro-nano lipid (SPNL) oral formulations were prepared and tested in rats for enhanced oral bioavailability of cannabidiol (CBD). Methods: The solid formulation at room temperature is a uniform solution of CBD in a mixture of solid lipids and surfactants. Upon contact with aqueous media, it disperses into <200 nm particles. Up to 40% w/w of CBD can be loaded in this formulation into a hard gelatin capsule or mixed with solid additives and compressed into a tablet. Another type of SPNL formulation was prepared from the absorption of a liquid pro-nano lipid formulation onto a solid support, termed LPNL. Results: Pharmacokinetic studies on male Wistar rats (0.295-0.335 kg) reveals that a single oral dose of SPNL or LPNL leads to rapid CBD absorption and high C_max values. The SPNL and LPNL formulations are stable at room temperature for at least 3 months. Powder forms of the SPNL and LPNL were prepared with Neusilin US2, SYLOID 244 FP, microcrystalline cellulose (Avicel PH 102), and mannitol. Both SPNL and LPNL show lesser stability for CBD with mesoporous silica particles such as Neusilin US2 and SYLOID 244 FP. Conclusions: The SPNL formulations do not contain any organic solvent and therefore are safer compared to the SNEDDS systems. These solid lipids-based oral formulations can be applied for the delivery of other lipophilic drugs.