3D-Printing-Assisted Fabrication and Characterization of Pregabalin-Loaded PVA/PVP Dissolving Microneedle Arrays

Background: A transdermal drug delivery system has significant benefits over conventional routes; however, its effectiveness is limited by the barrier properties of the stratum corneum. Dissolving microneedles (DMNs) have emerged as a minimally invasive strategy to enhance drug permeation while improving patient compliance. The integration of advanced fabrication techniques such as 3D printing enables precise control over microneedle geometry and reproducibility. Objective: This study aimed to fabricate and characterize pregabalin-loaded PVA/PVP dissolving microneedle arrays using a 3D-printing-assisted mold fabrication approach for efficient transdermal drug delivery. Methods: Microneedle master molds were fabricated using 3D printing, followed by replication using polydimethylsiloxane (PDMS) to obtain negative molds. Pregabalin-loaded bilayer microneedles were prepared using a micromolding technique with PVA/PVP polymers. The formulation was evaluated through rheological analysis, scanning electron microscopy (SEM), mechanical strength testing, insertion studies, swelling behavior, drug loading efficiency, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and in vitro drug release studies. Results: The fabricated microneedles exhibited uniform geometry with sharp tips and no structural defects. Rheological analysis confirmed shear-thinning behavior suitable for mold filling. The microneedles demonstrated adequate mechanical strength (~3.3 N/needle) and efficient insertion into the parafilm model. Drug loading efficiency was high (92.4%), indicating effective encapsulation. FTIR analysis confirmed compatibility between drug and polymers, while DSC and XRD results indicated partial amorphization of pregabalin within the polymer matrix. The formulation showed a biphasic drug release profile with an initial burst followed by sustained release, achieving ~96.8% cumulative release over 24 h. Conclusions: The study successfully demonstrates a robust and reproducible 3D-printing-assisted approach for fabricating pregabalin-loaded dissolving microneedles. The developed system exhibited desirable mechanical, physicochemical, and drug release properties, highlighting its potential as an effective transdermal drug delivery platform.