3D-Printed Mucoadhesive Hydrogel Buccal Films Based on HPMC and Carbopol Bioinks Incorporating...

Three-dimensional (3D) printing has emerged as a versatile platform in pharmaceutical sciences, enabling fabrication of personalized dosage forms with controlled drug release and tailored properties using printable hydrogel bioinks. This study aimed to develop mucoadhesive hydrogel buccal films for cannabinoid delivery using extrusion-based 3D bioprinting. The films incorporated cannabidiol (CBD) and tetrahydrocannabinol (THC) as cyclodextrin inclusion complexes with HPMC or Carbopol as mucoadhesive hydrogel-forming polymers, while terpenes were evaluated as permeation enhancers. Terpenes including 1,8-cineole, d-limonene, α-pinene, and L-menthol were investigated individually and in combinations to assess their ability to enhance buccal cannabinoid permeation. Hydrogel bioinks were prepared and characterized for viscosity, pH, and drug content prior to printing under optimized conditions. The printed films were evaluated for mechanical properties, swelling behaviour, mucoadhesion, in vitro drug release, and ex vivo buccal mucosal penetration. Ex vivo penetration studies demonstrated that combinations of natural terpenes significantly improved CBD penetration compared with individual terpenes and the synthetic enhancer Azone. HPMC-based hydrogel films exhibited superior mechanical strength, cohesive gel matrices, and sustained non-Fickian cannabinoid release, while enhancing transmucosal penetration compared with unformulated drugs. Carbopol-based films showed higher mucoadhesion but weaker mechanical properties and faster erosion-driven release. These findings demonstrate the potential of 3D-printed mucoadhesive hydrogel films as gel-based systems for transmucosal cannabinoid delivery.