3d printing of prolonged-release oral solid dosage forms containing felodipine

Coupling hot melt extrusion (HME) with 3D printing (3DP) through fused deposition modelling (FDM) allows today the manufacturing of oral solid dosage forms with desired characteristics, suitable for personalized medicine. Among the advantages of applying this combination of technologies in the manufacturing of oral solid dosage forms, one is that it enhances the solubility and bioavailability of poorly water-soluble compounds. In this context, our work aimed at the preparation of prolonged-release oral solid dosage forms containing felodipine, chosen as poorly water-soluble drug of BCS class II, by coupling HME with FDM. In a first step, the formulation and extrusion conditions for felodipine-loaded filaments were established. Regarding the formulation, filaments were prepared with felodipine loading from 5% to 50%, using polyvinyl alcohol as the main filament-forming polymer and mannitol as a plasticizer. Visual examination, mechanical and thermal characterization of filaments helped in the selection of adequate felodipine loading and extrusion conditions, which were dependent on active substance loading. The filaments with 5% and 15% felodipine were further used to 3D print tablets using FDM methodology, with tablet infill density ranging from 10% to 80%. The printed tablets were evaluated through in vitro drug release test, which revealed that the disintegration and dissolution behaviour is influenced by the active substance content of the dosage form, as well as by the infill density. Thus, the increase of felodipine content and of the infill percentage may be used as a strategy to prolong the release of felodipine from the 3D printed tablets.