Direct powder extrusion (DPE) 3D-printing of mini-tablets for preclinical studies in rodents

3D printing (3DP) plays a crucial role in accelerating formulation processes and significantly reduces the time needed to transition from concept to prototype. This technology is particularly valuable as it allows researchers to quickly adjust the structure and composition of dosage forms and efficiently evaluate multiple formulations for safety and efficacy. The following research explores the feasibility of using the direct powder extrusion (DPE) technique to produce 3D-printed mini tablets for eventual in vivo preclinical trials in rodents. The DPE method streamlines the manufacturing process into a single step and addresses the limitations commonly associated with Fused Deposition Modeling (FDM). It offers advantages such as customized small-batch production, optimized costs, and minimal waste. This allows pharmaceutical companies to quickly respond to market demands and improve overall product quality through detailed characterization. In this study cellulose-based polymers like Hydroxypropyl Cellulose (HPC-L) and Hydroxypropyl Methylcellulose (HPMC-15LV) were selected as the main matrix excipients, incorporating 10 % w/w of a model drug. The formulations were further optimized to achieve the best flowability and extrudability, as well as the most desirable printing resolution, to produce 3D-printed mini tablets resembling size 9 capsules. Based on the inner diameter of the cannula used for oral administration in rats, tablets measuring 8.6 × 1.8 × 1.8 mm were successfully printed. Thermal analysis (DSC and TGA) and solid-state characterization (FTIR, XRD) were employed to evaluate the physical properties of the powder blends and final 3D-printed products along with the assessment of desirable mechanical features. The successful production of small batches of model 3D-printed mini tablets that are suitable for in vivo testing and present comparable release profiles with conventional employed capsules demonstrated the possibility to implement DPE during preclinical development of novel formulations working independently from suppliers.