Development and in vitro Evaluation of Cannabidiol Mucoadhesive Buccal Film Formulations Using Hot-Melt Extrusion Technology.

Introduction: Cannabidiol (CBD) has sparked considerable interest because of its wide range of pharmacological uses and the fact that it does not induce psychoactive effects. CBD formulation development presents significant challenges due to its limited water solubility and susceptibility to first-pass metabolism, both of which restrict its overall bioavailability. The current research aimed to use hot-melt extrusion (HME) technology to develop mucoadhesive buccal films to improve CBD solubility and reduce first-pass metabolism.

Methods: Five formulations containing 10% w/w CBD were extruded using a counter-rotating twin-screw extruder (Haake Minilab II, Thermo Fisher Scientific). Different characterization studies were conducted on the developed formulations.

Results: Differential scanning calorimetry (DSC) revealed that the CBD endothermic peak disappeared in some of the developed films, indicating that CBD was converted from crystalline to amorphous form. A bio-adhesion study showed that the formulations containing Carbopol^® (BF2, BF3, BF4, and BF5) had higher adhesiveness properties. In vitro release and solubility studies showed an increase in CBD release and water solubility in the developed formulations when compared to pure CBD. Stability studies revealed that CBD content and release in the lead formulation (BF2) was stable over 15 months.

Conclusion: The current study demonstrates that HME was successfully used as an approach to develop CBD mucoadhesive buccal films and CBD solubility was enhanced.