Aversion liquid-filled drug releasing capsule (3D-RECAL): A novel technology for the development of immediate release abuse deterrent formulations using a fused deposition modelling (FDM) 3D printer.

COVID19 has caused a significant socioeconomic burden worldwide. Opioid crisis was further intensified with the increasing number of opioid overdose/misuse related deaths in last two years. Abusers have adopted newer/efficient methods for manipulating and abusing commercial opioid formulations. Food and Drug Administration (FDA) has been strategizing tirelessly to prevent misuse/abuse of prescription opioids. One of the strategies is to develop an abuse deterrent formulation (ADF). The current study aims to develop a novel 3D printed drug-releasing capsule shell filled with an aversion liquid (3D-RECAL). Primarily, metformin hydrochloride (MT, model drug) loaded printable filaments of polyvinyl alcohol was prepared using hot melt extrusion. Following extrusion, a 3D printed capsule shell was designed and fabricated using a single nozzle fuse deposition modelling 3D printer. An aversion liquid to be filled in 3D-RECAL capsules was prepared by combining sudan black and sodium polyacrylamide starch in oil base. Mechanical analysis of extruded filaments suggested that the filaments with 20%w/w MT had a higher mechanical strength compared to other drug loadings. Instantaneous gelling and large black non-snortable particles were formed during solvent extraction and physical manipulation studies, respectively. Due to the drug being embedded in the capsule shell, MT release was immediately started with >85% of MT release within 45 mins in 0.1 N HCl. Due to the everlasting need for the newer efficient ADF technologies, 3D-RECAL can be a step in the right direction towards saving lives, providing safe and effective measures to deterring abusers.