Powder bed fusion- laser beam (PBF-LB) three-dimensional (3D) printing: layer by layer through different types of photoabsorbers.

Powder bed fusion-laser beam (PBF-LB) was used to investigate the influence of three Candurin® pigments (Gold Sheen, NXT Ruby Red and Orange Amber, 3 % w/w) on the fabrication of thin dosage forms composed of Parteck® MXP 4-88 and zolpidem tartrate (ZT). The effects of photoabsorber type, model thickness and build orientation were evaluated. Horizontally printed dosage forms generally showed greater dimensional accuracy, whereas vertical printing was associated with larger z-axis deviations and one-sided bending deformation, likely due to the greater number of deposited layers. A statistically significant difference was observed between F Gold and F Ruby, while F Amber exhibited intermediate behaviour, indicating that photoabsorber type may contribute to early dissolution under the investigated conditions. MIP and SEM analyses revealed complex porous structures resulting from partial sintering, suggesting that drug release may reflect the combined influence of multiple microstructural characteristics rather than total porosity alone. Drug assay results indicated no substantial loss of recoverable ZT content, and FTIR analysis showed no evidence of drug-excipient interaction. These findings highlight the importance of photoabsorber selection and build orientation in modulating the internal structure and dissolution behaviour of thin dosage forms, supporting the potential of PBF-LB for future personalised dosing strategies.