Printabily of Pharmaceutical-Grade Polymers using Selective Laser Sintering with a CO2 Laser

Abstract

Selective laser sintering (SLS) has gained attention for pharmaceutical applications and the printing of solid oral dosage forms. The aim of this study was to evaluate the suitability of various pharmaceutical-grade polymers for tablet production using an SLS printer equipped with a CO₂ laser. Seven polymers, offering a range of release profiles such as immediate, controlled, and pH-dependent, were selected for investigation. Initially, the materials were characterized, revealing significant variations in their properties, including glass transition temperature, degradation temperature, mean particle size, and flowability. While some polymers exhibited ideal properties for printing, others were less suitable. By varying printing parameters such as the laser power, bed temperature, scanning speed, and powder feed rate, all powders were used for the reproducible fabrication of tablets. The physical properties of the tablets, including the hardness and friability, as well as their microstructure were affected by both the polymer grade and the laser intensity. The tablet physical characteristics varied according to the used polymer and thus hardness values ranged from 31 to 350 N, while friability varied across different formulations, with few tablets exhibiting values below 1%, others between 1–3%, and some exceeding 5%. Overall, this work demonstrated the suitability of using various pharmaceutical-grade polymers to produce tablets using SLS with a CO₂ laser.

Graphical Abstract