Tablet fragmentation without a disintegrant: A novel design approach

Fused deposition modelling (FDM) 3D printing has shown the most immediate potential for on-demand dose personalisation to suit particular patient's needs. However, FDM 3D printing often involves employing a relatively large molecular weight thermoplastic polymer and results in extended release pattern. It is therefore essential to fast-track drug release from the 3D printed objects. This work employed an innovative design approach of tablets with unique built-in gaps (Gaplets) with the aim of accelerating drug release. The novel tablet design is composed of 9 repeating units (blocks) connected with 3 bridges to allow the generation of 8 gaps. The impact of size of the block, the number of bridges and the spacing between different blocks were investigated. Increasing the inter-block spaces reduced mechanical resistance of the unit, however, tablets continued to meet pharmacopeial standards for tablet's friability. Upon introduction into gastric medium, 1 mm spaces tablet broke into mini-structures within 4 min and met the USP criteria of immediate release products (86.7% drug release at 30 min). Real-time ultraviolet (UV) imaging indicated that the cellulosic matrix has expanded due to swelling of HPC upon introduction to dissolution medium. This was followed by a steady erosion of the polymeric matrix at a rate of 8 μm/min. The design approach was more efficient than formulation approach of adding disintegrants to accelerate tablet disintegration and drug release. This work provides a unique example where computer-aided design was instrumental at modifying the performance of solid dosage forms. Such an example may serve as a foundation for a new generation of dosage forms with complicated geometric structures to achieve functionality that are usually reached by formulation approach.
Structure graphic and analytic results of 3D printed cellulosic tablets
3D printed cellulosic tablets