3D printing in drug delivery: emerging technologies, clinical translation, and the future of personalized medicine

• Compares major 3D-printing technologies for diverse drug delivery applications. • Discusses material, formulation, and regulatory barriers limiting clinical translation. • Explains the impact of geometry and multi-material design on drug-release behavior. • Reviews emerging trends such as AI-guided design, 4D printing, and point-of-care manufacturing. Three-dimensional (3D) printing has rapidly evolved into a transformative platform for drug delivery, offering capabilities that extend far beyond the customization possible with traditional manufacturing. This review critically evaluates the major 3D-printing technologies FDM, SLS, SLA/CLIP, SSE, and multi-material inkjet and compares their suitability across oral, transdermal, implantable, and bioprinted systems. Emphasis is placed on material limitations, polymer–drug compatibility challenges, quality-control constraints, and regulatory barriers that currently restrict translation. Recent advancements in nano-enabled formulations, stimuli-responsive architectures, and high-resolution multi-material systems are examined to illustrate how structural design directly influences pharmacokinetics and therapeutic performance. The review concludes with a forward-looking synthesis that highlights emerging opportunities in AI-assisted dosage design, 4D shape-morphing platforms, and point-of-care manufacturing workflows. Together, these insights provide a comprehensive and critical understanding of the technological, material, and regulatory factors shaping the future of 3D-printed drug delivery. By advancing innovation in pharmaceutical manufacturing and enabling more equitable access to personalized therapies, 3D printing represents a pivotal evolution toward patient-centric drug delivery solutions.