3D Printing for Personalised Medicines: Pharmaceutical Formulation Strategies, Dose Customisation and Regulatory Challenges

Abstract

Conventional mass-manufacturing of pharmaceuticals relies on fixed doses and standardised formulations that assume an 'average' patient, an approach that fails to account for the considerable inter-individual variability in age, weight, genetics, organ function and disease progression that governs drug response. Personalised medicine seeks to tailor therapy to the individual, and 3D printing provides a practical manufacturing platform capable of realising this vision at the point of care. This review examines the principal pharmaceutical 3D-printing technologies—including fused deposition modelling (FDM), semi-solid extrusion (SSE), selective laser sintering (SLS), stereolithography (SLA) and binder-jet (powder-bed) printing—and evaluates their suitability for producing solid oral dosage forms with customised doses, geometries, release profiles and multi-drug combinations. It further considers formulation strategies, including polymer selection, hot-melt extrusion coupling, printability and the incorporation of thermolabile and biologic actives. The landmark 2015 approval of Spritam® (levetiracetam), the first 3D-printed drug product cleared by the United States Food and Drug Administration, is discussed as a proof of concept that catalysed the field. The review also addresses the regulatory, quality-control and good-manufacturing-practice (GMP) challenges that arise when manufacturing is distributed to hospitals, community pharmacies and clinics rather than centralised in industrial facilities. Key barriers—process validation, real-time release testing, data integrity, excipient qualification and pharmacovigilance—are analysed alongside recent guidance from major regulatory agencies. A recurring theme is that the principal obstacles to adoption are no longer questions of technical feasibility but of quality assurance, standardisation and governance, particularly the difficulty of assuring dose accuracy and product quality when single units are printed on demand rather than sampled from large batches.