3D printing allows the production of pills with several different active ingredients useful for children and people with swallowing difficulties. The objective of this work is to model and 3D print a capsule containing dronedarone hydrochloride embedded in a polymer filament as the main active ingredient and omega-3 fatty acid powder as an excipient. The research hypothesis is that the bioavailability of dronedarone hydrochloride increases in the presence of omega-3 fatty acids. In this research, a capsule is produced that allows simultaneous ingestion of dronedarone hydrochloride and omega-3 fatty acid. The 3D printing was preceded by the creation of a 3D model of the capsule in a computer program and the extrusion of filament with two formulations of 10 and 15 percent dronedarone by weight. The capsules were filled with omega-3 fatty acid powder and an in vitro release test was performed. Both capsules, with and without omega-3 fatty acids, were studied. The release profiles of dronedarone were compared and their differences quantified using difference and similarity factors. The results showed that the samples containing omega-3 fatty acids exhibited a faster release of dronedarone in vitro than the samples not containing this additive. In addition, a faster release was observed in samples with a greater amount of dronedarone in the filament due to a higher driving force. Difference and similarity factors showed that there is a statistically significant difference in the release profiles of dronedarone between capsules with and without omega-3 fatty acid. It can be concluded that omega-3 fatty acids significantly increase the bioavailability of dronedarone in the body. The capsule model developed is suitable for the simultaneous administration of multiple active ingredients or excipients.