A Lower Temperature FDM 3D Printing for the Manufacture of Patient-Specific Immediate Release Tablets

Purpose. The fabrication of a ready-to-use immediate release tablets via 3D printing provides a powerful tool to on-demand individualization of dosage form. This work aims to adapt a widely used pharmaceutical grade polymer, polyvinylpyrrolidone (PVP), for instant on-demand production of immediate release tablets via FDM 3D printing. Methods. Dipyridamole or theophylline loaded filaments were produced via processing a physical mixture of API (10%) and PVP in the presence of plasticizer through hot-melt extrusion (HME). Computer software was utilized to design a caplet-shaped tablet. The surface morphology of the printed tablet was assessed using scanning electron microscopy (SEM). The physical form of drug and its integrity following an FDM 3D printing were assessed using x-ray powder diffractometry (XRPD), thermal analysis and HPLC. In vitro drug release studies for all 3D printed tablets were conducted in a USP II dissolution apparatus. Results. Bridging 3D printing process with HME in the presence of a thermostable filler, talc, enabled the fabrication immediate release tablets at temperatures as low as 110oC. The integrity of two models drugs was maintained following HME and FDM 3D printing. XRPD indicated that a portion of the loaded theophylline remained crystalline in the tablet. The fabricated tablets demonstrated excellent mechanical properties, acceptable in-batch variability and an immediate in vitro release pattern. Conclusions. Combining the advantages of PVP as an impeding polymer with FDM 3D printing at low temperatures, this approach holds a potential in expanding the spectrum of drugs that could be used in FDM 3D printing for on demand manufacturing of individualised dosage forms

On demand manufacturing of patient-specific liquid capsules via co-ordinated 3D printing and liquid dispensing

A method for the production of liquid capsules with the potential of modifying drug dose and release is presented. For the first time, the co-ordinated use of fused deposition modelling (FDM), 3D printing and liquid dispensing to fabricate individualised dosage form on demand in a fully automated fashion has been demonstrated. Polymethacrylate shells (Eudragit EPO and RL) for immediate and extended release were fabricated using FDM 3D printing and simultaneously filled using a computer-controlled liquid dispenser loaded with model drug solution (theophylline) or suspension (dipyridamole). The impact of printing modes: simultaneous shell printing and filling (single-phase) or sequential 3D printing of shell bottom, filling and shell cap (multi-phase), nozzle size, syringe volume, and shell structure has been reported. The use of shell thickness of 1.6 mm, and concentric architecture allowed successful containment of liquid core whilst maintaining the release properties of the 3D printed liquid capsule. The linear relationship between the theoretical and the actual volumes from the dispenser reflected its potential for accurate dosing (R  = 0.9985). Modifying the shell thickness of Eudragit RL capsule allowed a controlled extended drug release without the need for formulation change. Owing to its low cost and versatility, this approach can be adapted to wide spectrum of liquid formulations such as small and large molecule solutions and obviate the need for compatibility with the high temperature of FDM 3D printing process. In a clinical setting, health care staff will be able to instantly manufacture in small volumes liquid capsules with individualised dose contents and release pattern in response to specific patient's needs. [Abstract copyright: Copyright © 2017. Published by Elsevier B.V.

Can Filaments be stored as a shelf-item for on-demand manufacturing of oral 3D printed tablets? An initial stability assessment

3D printing of oral solid dosage forms is a recently introduced approach for dose personalisation. Fused deposition modelling (FDM) is one of the promising and heavily researched 3D printing techniques in the pharmaceutical field. However, the successful application of this technique relies greatly on the mass manufacturing of physically and chemically stable filaments, that can be readily available as a shelf item to be 3D printed on-demand. In this work, the stability of methacrylate polymers (Eudragit EPO, RL, L100-55 and S100), hydroxypropyl cellulose (HPC SSL) and polyvinyl pyrrolidone (PVP)-based filaments over 6 months were investigated. Filaments manufactured by hot melt extrusion (HME) were stored at either 5 oC or 30 oC + 65 %RH with/without vacuuming. The effects of storage on their dimensions, visual appearance, thermal properties, and ‘printability’ were analysed. Theophylline content, as well as in vitro release from the 3D printed tablets were also investigated. The filaments were analysed before storage, then after 1, 3 and 6 months from the manufacturing Storing filaments at these conditions had a significant effect on their physical properties such as shape, dimensions, flexibility and hence compatibility with FDM 3D printing. In general, the methacrylate-based filaments were more physically stable and compatible with FDM 3D printing following storage. Owing to their hygroscopic nature, cellulose- and PVP-based filaments demonstrated a reduction in their glass transition temperature upon storage, leading to increased flexibility and incompatibility with FDM 3D printer. Theophylline contents was not significantly changed during the storage. This work provides preliminary data for the impact of polymer species on the long-term stability of the filaments. In general, storage and packaging conditions have major impact on the potential of on-demand manufacturing of 3D printed tablets using hot melt extruded filaments