Reusable gelatin-based inks for 3D printing of veterinary gabapentin tablets: a sustainable approach

Gabapentin (GAB), an anticonvulsant, is commonly used in veterinary medicine to manage anxiety, pain, and epilepsy. Although it is widely used, achieving personalized dosing for small animals remains a significant challenge. Three-dimensional printing (3DP), particularly semi-solid extrusion (SSE), has shown promise in producing individualized dosage forms efficiently and with precision. Despite its advantages, SSE is limited by the need to freshly prepare the ink for printing and the extended post-processing times required for curing or solidifying the printed objects. This study investigated for the first time the feasibility of reusing a formulation designed for veterinary patients. The chewable tablets in this study were made using an already available proprietary gelatin-based excipient base, CuraVet®. Two formulations with varying GAB concentrations were printed using the same syringe initially and then again after 14 days of refrigerated storage. The formulation that contained a lower concentration of GAB maintained printability and dosing precision without requiring adjustments to printer settings, enabling the production of chewable tablets in under 30 min with a minimal amount of active work required. In contrast, the higher concentration formulation exhibited crystal formation, indicating instability. This proof-of-concept study demonstrated the feasibility of using reusable gelatin-based inks for on-demand 3D printing of veterinary medicines, highlighting their potential for clinical adoption in veterinary practices and pharmacies, provided that stability is carefully characterized.