3D printed mini pills for site-specific release and controlled absorption of metronidazole

This study presents an approach to develop extrusion-based three-dimensional printing (3DP) of Metronidazole (MTZ)-loaded mini-pills formulated via fused deposition modelling (FDM) using shape-memory polymers (SMPs) blended for controlled, and site-specific oral drug delivery. Computer-aided design (CAD) software was used to create the mini-pill design, and 3D-printed prototypes were prepared by adjusting the extrusion printing parameters. The mini-pills were examined for their thermal behaviour, crystallinity, molecular interactions, and surface structure using several analytical techniques, such as differential scanning calorimetry (DSC), X-ray diffraction (XRD), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), field-emission scanning electron microscopy (FESEM), and 3D surface profilometry. A reverse-phase high-performance liquid chromatography (RP-HPLC) validated method was used to quantify MTZ entrapment efficiency and release kinetics. In vitro MTZ release studies were carried out in simulated gastric and intestinal fluids, revealing a pH-responsive release pattern with roughly 25% of MTZ released over 48 h. The mini-pills were further assessed through in vivo pharmacokinetic (PK) evaluation, using parameters like C max , T max , AUC 0−t , and AUC 0−∞ , these results indicated good drug absorption in six healthy albino rabbits. The MTZ-loaded mini-pills showed a C max of 12.13 ± 0.19 µg/mL and a T max of 8 h. These results indicated sustained systemic exposure and controlled absorption of MTZ from the developed 3DP mini-pills.