(M1430-12-69) Development of Multilayer 3D DLP Printed Tablet in One Step Using Automated Rotary Platform

Purpose: The objective of this study is to determine a way to automate the current process to manufacture multi-layered tablets in a more efficient, hands-free, and less error-prone manner.

Methods: A 3D printed design software, Autodesk Fusion 360, was used to create a new build platform, housing chamber for a mini servo motor, and a mounting mechanism that would allow the entire apparatus to connect to the MicroDLP 3D printer. The STL files containing these designs will be used to 3D print each component of the assembly using a Form 2 stereolithographic (SLA) 3D printer. The Arduino coding software was used to develop a coding sequence capable of inducing the mini servo motor to rotate after a specified period of time. The original resin tank is removed and replaced with a 12-well plate. The middle two wells will only be used in this printing method, each filled with a different photocurable resin formulation with a different active pharmaceutical ingredient (API). The rotary platform has two printing surfaces that lower into the middle two wells at the beginning of the printing process. The rotary platform stayed in this position while the first half of the tablet was formulated. After half of the tablet was formulated, the platforms will lift up and rotate 180-degrees. This rotation caused the two printing surfaces to trade positions. When the rotary platform lowered back into the wells to continue the printing process, the two printing surfaces were in the wells opposite from the ones they printed in during the first half of the process. At the end of the printing process, each tablet possessed two layers consisting of the two resin formulations. The formulated multi-layered tablets were evaluated via hardness testing, texture analysis, weight variation, friability testing, digital scanning calorimetry, and in vitro release studies.

Results: The results showed that the tablets formulated using the automated rotary platform passed the weight variation, friability, and hardness tests in accordance to USP guidelines. The results of the in vitro drug release tests also showed >60% release of both the APIs after 24 hours.

Conclusion: This is the first report of an automated protocol to 3D print multilayered tablets using DLP 3D printing. In conclusion, the automated rotary platform design for printing multilayered multidrug tablets investigated in this study proved to be superior to the current tablet printing methods.


Figure 1 illustrates the fully assembled rotary build platform apparatus and how it will fit into the 12-well plate containing the two resin formulations.