The aim of this work is to prepare filaments containing dronedarone hydrochloride as an active pharmaceutical ingredient by hot melt extrusion at the lowest possible temperature due to the thermal sensitivity of the active pharmaceutical ingredient. In addition, the filaments were used for the fabrication of cubes by 3D printing process, which were subsequently characterized. Mixtures of dronedarone hydrochloride, polycaprolactone, polyethylene glycol and Soluplus in different proportions were used in the preparation of the filaments, from which three filaments were prepared: Dronedarone-polycaprolactone (F), Dronedarone-polycaprolactonepolyethylene glycol (FP) and Dronedarone-polycaprolactone-Soluplus (FS). The filaments were extruded at 100 ℃, and their diameter was measured using a digital moving gauge. The obtained filaments were used to make cubes with a 3D printer, which were subjected to a swelling test in three solutions: distilled water, phosphate buffer and hydrochloric acid. The content of dronedarone in the filaments and cubes was determined by UV/Vis spectrophotometry. The results show that the filament FP has the diameter closest to the target value of 1.75 mm required for a 3D printer and that the diameter variations along the filament are the smallest. The highest percentage of dronedarone was achieved with the FS filament. Of the printed cubes, the FS cube is the most visually correct, while more DNR is released from the FP cube. The spectrophotometrically determined content of dronedarone in filaments and cubes is significantly lower than the actual content. One possible reason for this is the poor solubility of polycaprolactone in acetone, which resulted in incomplete dissolution of dronedarone. The results of the swelling test showed a slight increase in mass after three days in all solutions. Despite the lower processing temperatures achieved when using polycaprolactone, the disadvantage is the low swelling intensity and thus the very slow release of the active ingredient.