3D printing for drug manufacturing: A perspective on the future of pharmaceuticals

Abstract

Since a three-dimensional (3D) printed drug was first approved by the Food and Drug Administration in 2015, there has been a growing interest in 3D printing for drug manufacturing. There are multiple 3D printing methods - including selective laser sintering, binder deposition, stereolithography, inkjet printing, extrusion-based printing, and fused deposition modeling - which are compatible with printing drug products, in addition to both polymer filaments and hydrogels as materials for drug carriers. We see the adaptability of 3D printing as a revolutionary force in the pharmaceutical industry. Release characteristics of drugs may be controlled by complex 3D printed geometries and architectures. Precise and unique doses can be engineered and fabricated via 3D printing according to individual prescriptions. On-demand printing of drug products can be implemented for drugs with limited shelf life or for patient-specific medications, offering an alternative to traditional compounding pharmacies. For these reasons, 3D printing for drug manufacturing is the future of pharmaceuticals, making personalized medicine possible while also transforming pharmacies.

Keywords: drug dosing and delivery; drug release characteristics; hydrogels; personalized medicine; three-dimensional (3D) printing.

Figure 1

3D printing methods for drug manufacturing. (A) Selective laser sintering. A laser is directed towards a bed of powder which is refilled by a roller system; the laser solidifies the powder to form the desired print. (B) Binder deposition. A binding solution is spotted onto a bed of powder which is refilled by a roller system; upon contact, the binder causes the powder to dissolve and re-crystalize. (C) Stereolithography. A laser is directed towards an inverted print bed which is submerged in a pool of photosensitive ink; the ink is cured and solidified by the laser. (D) Inkjet printing. On the left, a thermal inkjet nozzle uses a heating element to create a bubble in the continuous flow of ink, which generates a droplet. On the right, a piezoelectric element uses electrical pulses to create an acoustic wave which causes the formation of an air bubble, thereby generating a droplet. (E) Extrusion-based printing (of viscous materials). On the left, a piston is used to apply mechanical pressure to the ink to extrude a continuous stream. On the right, pneumatic pressure is applied from above to extrude the ink. (F) Fused deposition modeling (for solid materials). Solid filament is fed through the nozzle by rollers, then melted by heating elements within the nozzle, and extruded on the print bed.

Figure 2

Theoretical scheme of 3D printing for drug manufacturing. Based on a patient’s specific prescription from his doctor, a custom medication is designed via computer-aided design. The dosage form may be composed of complex geometries, multiple doses, or even multiple drugs. Drug-loaded bioink (biocompatible material) is then 3D printed on-demand.