Functions of Magnetic Nanoparticles in Selective Laser Sintering (SLS) 3D Printing of Pharmaceutical Dosage Forms

Selective laser sintering (SLS) 3D printing (3DP) offers novel opportunities for manufacturing various pharmaceutical dosage forms with a wide array of drug delivery systems. The purpose of this research was to introduce ferromagnetic nanoparticles, for the first time, as a multi-functional magnetic and heat conductive ingredient for 3DP tablet formulations, and further to analyze its effect on the drug release of the SLS printed tablets under a specially designed magnetic field. Optimization of tablet quality was performed by adjusting SLS printing parameters. The independent factors studied were laser scanning speed (2, 50, 100, and 200 mm/s), hatching space (13, 25, 50, 100, 300, and 2000 µm), and temperature. The responses measured were tablet weight, hardness, disintegration time (DT), and dissolution kinetics studied within the first hour. The content uniformity, chemical interaction, drug distribution, and surface morphology were tested for characterizing the printed dosage forms. It has been observed, for the drug formulations with carbonyl iron, due to its inherent heat conductivity, that sintering tablets required low energy input compared to that of other batches that contained no magnetic particles, to make the tablets of the same quality attributes. Also, under the magnetic field, printed tablets with carbonyl iron released 25% more drug as compared to those without. Therefore, we report for the first time the use of magnetic nanoparticles as a novel conductive excipient to sinter the particles in an SLS 3D printing process of pharmaceutical dosage forms and hence this finding opens up numerous opportunities for magnetically triggerable drug delivery systems.