Pharmaceutical evaluation of matrix tablets prepared using a fused deposition modelling type three-dimensional printer - Effect of geometrical internal microstructural factors on drug release from enteric-polymer tablets containing rebamipide

Three-dimensional (3-D) printers are widely expected to provide a novel manufacturing method in the future to make personalized medicines in hospitals.

Functional filament containing 5-20% drug was prepared with rebamipide (REB; a poorly water-soluble model drug) and hypromellose phthalate (HPMCP; enteric base) at 130-170°C using a biaxial kneading extruder. Several tablet models with various internal structures were designed using computer-aided design. REB-containing 3-D tablets were prepared based on these designs from filament using a fused deposition modelling type 3-D printer.

Physicochemical characteristics of the filament and 3-D tablets were measured by powder X-ray diffraction and differential scanning calorimetry. The results suggested that a part of the crystalline REB dispersed into the HPMCP and transformed into an amorphous form, because crystalline REB was kneaded with melted HPMCP at 130-170°C during the preparation processes of filament and 3-D tablets. The drug-release properties of 3-D tablets were tested in both pH 1.2 and 6.8 buffers. REB was not released from the 3-D tablets at pH 1.2, but HPMCP dissolved at pH 6.8, and then REB was rapidly released from the tablet.

The dissolution of 3-D tablets in the small intestine could be controlled by the tablet geometrical structure.