A comprehensive overview of extended release oral dosage forms manufactured through hot melt extrusion and its combination with 3D printing.

Oral dosage formulations are considered to be the most convenient pharmaceutical dosage forms for almost all ages because of their simplicity and non-invasive administration compared to other dosage forms. To improve therapeutic efficacy and avoid frequent daily doses, extending drug release profile is of great interest in pharmaceutical industry. Hot-Melt Extrusion (HME) has gained great attention in pharmaceutical industry since it is one of the continuous manufacturing processes, which can cut down production steps and human errors as opposed to batch to batch process. This controlled and continuous process can improve product quality and reproducibility. HME is a versatile technology, where controlled/sustained oral dosage forms have been one of its important production lines. With the emergence of 3D printing, the future of personalized medicine has become more applicable. Recently, there is a great orientation towards the combination of HME and Fused Deposition Modelling (FDM), in an aim to be a continuous process for personalized and telemedicine. Several extended-release formulations have been manufactured successfully through HME coupled with FDM. This review will shed light on pharmaceutical approaches used to control and sustain drug release in oral formulations by HME and its combination with FDM 3D printing. Quality by design approaches and critical process- and formulation-related factors that affect the release profiles in both HME and FDM will be also discussed clearly in this review.