22 - Medical additive manufacturing in pharmacy

Abstract

Conventional manufacturing techniques have limitations in providing easily recognizable, patient-tailored medicines and are easier to counterfeit owing to the simple process. These limitations associated with conventional manufacturing techniques open up new opportunities for the creation of novel dosage forms with distinctive shapes and improved functionality that would get over the physiological constraints of the gastrointestinal tract. These opportunities can be met by employing additive manufacturing (AM) mainly 3D, 4D, 5D, and 6D printing technology which is an emerging field in the healthcare sector. 3D printing enables the reduction of manufacturing steps, production of personalized medicines, and control over therapeutic dosage. However 3D printing technology presents the main hurdle of poor mechanical strength of dosage forms like tablets and capsules owing to the flat print surface which leads to the creation of more advanced technologies such as 4D, 5D, and 6D printing technology. 4D printing technology provides supplementary support material for printing in complex geometry like curved surfaces but has the limitation of the requirement of extra provocations to alter the morphology of the printed geometry. 5D printing was evolved to tackle the limitation of 4D printing in which the printing of products involved three movements and two rotating axes without the necessity of supplementary support material. Moreover, 6D printing technology utilizes the principles of 5D printing in addition to smart materials. Various software are available for AM including TinkerCAD, Ultimaker Cura, Meshmixer, Meshlab, Netfabb. Pharmaceutical AM entails several steps that must be completed to get the desired outcome. Despite the technology’s potential, numerous clinical and regulatory issues must be resolved before AM fabricated therapies for precision medicine applications are widely adopted. This review explores various AM techniques in designing dosage forms along with their opportunities and challenges.