Tunable Drug Release from 3D-Printed Bilayer Tablets: Combining Hot-Melt Extrusion and Fused Deposition Modeling

Area of Science:

• Pharmaceutical Technology
• Materials Science
• Drug Delivery Systems

Background:

• Controlled-release dosage forms are crucial for optimizing therapeutic efficacy and patient compliance.
• 3D printing offers a promising avenue for fabricating complex drug delivery systems with tailored release profiles.

Purpose of the Study:

• To develop and evaluate a practical 3D printing approach for manufacturing oral controlled-release bilayer tablets.
• To demonstrate the modulation of drug release by controlling the layer ratio in bilayer tablets fabricated via fused deposition modeling (FDM).

Main Methods:

• Theophylline-loaded filaments were prepared using hot-melt extrusion (HME) with Kollicoat® IR or hydroxypropyl cellulose.
• Filament mechanical properties were assessed for suitability in FDM 3D printing.
• Bilayer tablets were fabricated using a dual-nozzle FDM 3D printer with varying layer ratios.
• Physicochemical characterization (SEM, DSC, XRD, FTIR) and in vitro drug release studies were performed.

Main Results:

• Manufactured filaments exhibited suitable mechanical properties for FDM printing.
• Physicochemical analyses confirmed drug dispersion within polymer matrices.
• Successfully fabricated bilayer tablets with different layer ratios, demonstrating distinct drug release profiles dependent on composition.
• Drug release was effectively controlled by altering the bilayer structure.

Conclusions:

• A combined HME-FDM 3D printing approach enables the geometric modulation of bilayer structures for controlled drug release.
• This method provides a practical platform for personalized oral drug delivery without increased formulation complexity.
• Layer ratio control in bilayer 3D printed tablets is an effective strategy for modulating drug release kinetics.