(T1530-06-37) Engineering Oral Tablets with Precision: A Deep Dive into SLS 3D Printing, Drug Release, and Material Characterization

Purpose: This study aims to explore how different formulation variables and different laser speeds in Selective Laser Sintering (SLS) 3D printing impact the drug release behavior and thermal stability of oral solid dosage forms. By adjusting parameters like laser speed, temperature, and layer thickness, and evaluating their interaction with excipient combinations, the goal is to improve tablet performance in terms of dissolution and minimize degradation. Ultimately, this research supports the potential of SLS 3D printing for creating customized and efficient oral drug delivery systems.

Methods: Oral solid dosage forms were fabricated using SLS 3D printing by systematically varying key parameters such as laser speed, surface temperature, and layer height. The formulations were evaluated for drug assay, mechanical integrity, and dissolution performance. Solid-state characterization included Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Powder X-Ray Diffraction (pXRD), Mass Spectrometry, and Proton Nuclear Magnetic Resonance (¹H NMR) to assess drug stability, interactions and degradation. Surface properties were analyzed through contact angle measurements to study wettability and potential effects on dissolution.

Results: The 3D printed oral solids of Indomethacin were successfully developed using different formulation variables and printing parameters. Drug release was significantly improved in all the formulations when performed dissolution in transit media. Release order kinetics were performed to know the mechanism of drug release and drug followed Korsmeyer Peppas kinetic model. FTIR analyses confirmed that the drug remained stable under optimized SLS printing conditions, with no significant signs of interactions. DSC and PXRD patterns showed a transition from crystalline to partially or fully amorphous forms depending on formulation composition and laser parameters, indicating successful dispersion of indomethacin in lead formulation. High-resolution mass spectrometric analysis detected no major degradation products. Additionally, ¹H NMR spectra confirmed structural integrity of the drug in all optimized formulations. Contact angle measurements showed increased surface wettability, correlating with faster dissolution rates.

Conclusion: The findings of this study highlight the critical role of SLS 3D printing conditions and formulation design in shaping the performance of oral solid dosage forms. By fine-tuning process parameters, it was possible to produce tablets with enhanced drug release, preserved chemical integrity, and reliable structural properties. These results support the use of SLS as a promising approach for creating patient-specific oral formulations with consistent and effective drug delivery.

References: 1. Zhang Y, Thakkar R, Zhang J, Lu A, Duggal I, Pillai A, Wang J, Aghda NH, Maniruzzaman M. Investigating the use of magnetic nanoparticles as alternative sintering agents in selective laser sintering (SLS) 3D printing of oral tablets. ACS Biomaterials Science & Engineering. 2023 Feb 6;9(6):2924-36.
2. Brambilla CR, Okafor-Muo OL, Hassanin H, ElShaer A. 3DP printing of oral solid formulations: A systematic review. Pharmaceutics. 2021 Mar 9;13(3):358.
3. Adamov I, Stanojević G, Kočović D, Mugoša S, Grujić B, Ibrić S. Selective laser sintering (SLS) 3D printing process: Influence of model design on the properties of zolpidem tartrate tablets. Macedonian Pharmaceutical Bulletin. 2023;69(Suppl 1):133-4.


Formulation composition (%w/w) and Printing Parameters


pH shift dissolution for F1-F6 with different laser speeds in transit media


PXRD and NMR Spectroscopy of pure API and all the formulations (F1-F6)