Current formulation approaches in design and development of solid oral dosage forms through three-dimensional printing

Three-dimensional (3D) printing technologies are continuously applied to novel fields, laying the foundations for a new industrial revolution. With regard to pharmaceutical sciences, 3D printed drug products are emerging as attractive and innovative tools in personalised medicine. For example, solid oral dosage forms (e.g. tablets) can be printed in a wide range of dosages, release profiles, geometries and sizes by simply modifying a digital model, thus providing patients with tailored therapies. Various 3D printing technologies have been applied to pharmaceutical manufacture in recent years, and different materials have been investigated to fabricate solid oral dosage forms in a broad range of properties. Therefore, the aim of this review is to describe the state of the art of 3D printing oral pharmaceuticals, with the view to provide formulation scientists with essential information to approach the development of 3D printed drug products, from digital design to final product quality control. Short- to long-term potential areas of application of 3D printed drug products and their relative regulatory pathway challenges are also presented.