3D-printing and hot-melt extrusion
3D-printing is also known as additive manufacture, and is a digitally controlled deposition of materials (layer-by-layer) to create objects with unlimited variety of geometries.
An object is typically designed using a digital modelling program such as CAD (computer-aided design) or animation modelling software. The design is transferred to the 3D printer, and the 3D printer head moves over the building plate along defined x, y, z coordinates depositing layers of material to create the three dimensional object.
3D printing methods have been extensively used in various other fields, also in biomanufacturing, e.g. for bone and tissue engineering, for implants, prosthetics and for medical devices. The first 3D printed tablet was approved by US Food and Drug Administration (FDA) in August 2016, (Spritam®) for epilepsy treatment.
Various 3D printing technologies are available; in our research we use the so called “fused deposition modelling” (FDM), where a drug-loaded filament is used as the building material. The drug filament can be prepared from thermoplastic polymers, by hot-melt extrusion (HME). The drug is dissolved or dispersed in the polymer melt, and may form a solid solution or an amorphous solid dispersion.