A review of hot melt extrusion paired fused deposition modeling three-dimensional printing for developing patient centric dosage forms

In recent years, the demand for developing patient-centric dosage forms is increasing enormously with the increasing patient population. Much research is ongoing exploring various additive manufacturing techniques for developing pharmaceutical medications. Poor solubility of drug substances and underdeveloped manufacturing strategies are majorly affecting the pharmaceutical industry's revenue. Developing intravenous dosage forms for drug substances with poor solubility will affect the revenue of the pharmaceutical industries. Thus, improving solubility remains to be the major prerequisite for the developmental scientist. In addition to improving solubility, establishing a robust manufacturing process with commercial viability is also essential. In recent years hot melt extrusion (HME) has been most widely investigated for developing amorphous solid dispersions (ASDs) over other techniques such as spray drying and KinetisolÒ. The process of HME can be coupled with the fused deposition modeling (FDM) three-dimensional (3D) printing technique which is capable of fabricating on-demand patient-centric dosage forms. A continuous manufacturing line can be established by painting HME and FDM 3D printing processes. The quality of the product can be controlled and monitored by employing suitable process analytical technology (PAT) tools. Though the process of the HME-paired FDM 3D printing process has resulted in various advantages compared to the conventional manufacturing process, still many limitations, such as the limited number of polymers, reproducibility, and stability, need to be addressed.