Three-dimensional drug printing: A structured review

Objectives: To summarize the published literature on existing three-dimensional (3D) printing (3DP) technologies for pharmaceutical manufacturing, describe the limitations of the 3DP process, and highlight the potential of these technologies in pharmacy practice. Data sources: A structured search of PubMed and Embase was performed to identify articles published between January 1, 1990, and August 31, 2012. Search terms included drug printing, drug 3D printing, and drug three-dimensional printing. Study selection: Original research articles describing 3DP related to drug manufacturing were included. Data extraction: "Ink" formulation, printing substrate, printing technology, drugs printed, and results of each study. Data synthesis: 21 of 511 identified references were included in the review. Inkjet and powder-based printing were the primary printing technologies used for drug development and fabrication. Eleven articles described a powder delivery system, and 10 identified inkjet printing. These printing technologies are currently being used in the pharmaceutical manufacturing process with the promise to transform pharmacy practice. Advantages include precise control of droplet size, high reproducibility, complex drug release profiles, and personalized medication therapy. Conclusion: Individualized medications fabricated through 3DP may offer an important benefit to patients. Printable dosage forms on paper may be easier to deliver to the patient than powder-based printed forms. In addition, medications that have narrow therapeutic indices or have a higher likelihood to be influenced by genetic polymorphisms may be the first to be printed via this technology.