Opportunities and challenges of three-dimensional printing technology in pharmaceutical formulation development

3D-Printing of Drug-Eluting Implants: An Overview of the Current Developments Described in the Literature

“…They enable the use of different materials such as polymers, ceramics or metals, as well as providing different resolutions for the printed objects [ 13 , 15 , 17 , 18 , 19 , 20 ]. All of these have advantages and disadvantages as summarized in Table 1 [ 13 , 17 , 20 , 21 , 22 , 23 ]. A schematic illustration of the printing techniques is shown in Figure 1 and a brief outline of the basic mechanisms is given in the following sections.…”

“…While a variety of filaments are available from different suppliers for standard technical FDM 3D-printing, the desired compositions for medical or pharmaceutical usage need often to be fabricated using a single or twin-screw extruder under convenient conditions for each composition [ 27 ]. The high operating temperatures during this printing process, which are mostly over 150 °C, limit the selection of accessible materials due to the risk of degradation of the drug or excipients [ 13 , 22 ]. Especially two-fold thermal stressing during HME and printing process should be considered with this technique.…”

“…Compared to other printing techniques, lower resolutions in the range of approximately 0.4–0.8 mm are obtained by extrusion-based 3D-printing depending on the nozzle used [ 13 , 20 , 29 ]. Printing is mostly processed at low temperatures and is, therefore, suitable for thermolabile substances [ 13 , 22 , 29 ]. Additionally, high drug loads can be achieved using this technique [ 15 ].…”

“…The selective laser melting (SLM) technique acts similarly, where the laser melts the powdered materials. The high energy input has to be considered because it could degrade drugs or excipients [ 13 , 22 ]. These high-resolution objects can be printed without the need for supporting structures, due to the surrounding powder [ 13 , 22 ].…”

“…The high energy input has to be considered because it could degrade drugs or excipients [ 13 , 22 ]. These high-resolution objects can be printed without the need for supporting structures, due to the surrounding powder [ 13 , 22 ]. However, the remaining unsintered powder requires removal during postprinting processes, and generates waste because reuse is not suitable for unlimited cycles due to possible alteration of the materials [ 13 , 23 , 30 ].…”