Drug Incorporation into Polymer Filament Using Simple Soaking Method for Tablet Preparation Using Fused Deposition Modeling

: The use of three-dimensional (3D) printing technology is expanding in various fields. The application of 3D printing is expected to increase in the pharmaceutical industry after 3D-printed tablets were approved by the U.S. Food and Drug Administration (FDA). Fused deposition modeling (FDM), a type of 3D printing, has been extensively studied for the manufacturing of tablets. A drug-loaded polymer filament, the ink of FDM 3D printers, can be prepared using the hot melt extrusion method or a simple drug-soaking method. In the present study, we investigate the influence of the experimental conditions on the loading of curcumin (model drug with fluorescence) into a polyvinylalcohol polymer filament using the soaking method. We show that organic solvent type (isopropanol, methanol, acetone, and ethanol), temperature (25 and 80°C), and drug concentration (2-333 mg/mL) greatly affect drug loading. Around 5% curcumin can be incorporated into the polyvinylalcohol filament using the soaking method. The drug dissolution from 3D-printed tablets depends on the drug content in the polymer filament. The incorporation of a higher amount of curcumin, which has poor water solubility, greatly delays drug dissolution. These results provide useful information on the preparation of 3D-printed tablets using a drug-loaded polymer filament obtained with the soaking method.