Effects of excipient properties on pharmaceutical printlet fabrication via selective laser sintering 3D printing

In this study, the impact of excipients on the quality of printlets manufactured using selective laser sintering (SLS) 3D printing was investigated. Various thermoplastic polymers, commonly used as pharmaceutical additives, and mannitol of different particle property grades, were used as excipients. SLS can produce complex structures and customize drug release rates; therefore, it can be used for personalized medicine. The significance of selecting suitable excipients, focusing on their powder flowability and printability, and their influence on the printlet properties was evaluated. An optimal amount of yellow iron oxide, a necessary laser-absorbing agent for printlet formation, was determined. Results revealed that excipients with optimal flow and shape characteristics considerably enhanced the printlet quality. The relation between the powder properties of excipients (internal friction angle, shear adhesion force, and flow function coefficient) and the SLS printing outcomes was evaluated using the powder shear cell test. The powder properties considerably affected the application of the powder layer using a spreader from the powder reservoir to the building platform. Moreover, the electron laser density impacted the printlet hardness. The as-fabricated printlets exhibited higher porosity and faster dissolution rates than traditional tablets, suggesting the potential advantages of using SLS in drug manufacturing.