4D-Printed Smart Drug Delivery Systems: The Next Generation of Personalized Pharmaceuticals

The evolution of additive manufacturing has transitioned from static 3D structures to dynamic 4D-printed systems, marking a paradigm shift in pharmaceutical technology [1,2]. 4D printing incorporates the dimension of time, allowing 3D-printed constructs to undergo programmed transformations in response to external stimuli such as pH, temperature, moisture, or enzymatic activity [1,3,6].This review examines the application of 4D printing in developing smart drug delivery systems (SDDS) tailored for personalized medicine [11, 28]. We examine the fundamental principles of shape-memory polymers and hydrogels used as smart inks [4, 17, 25]. The manuscript further discusses how these systems overcome the limitations of traditional dosage forms by providing site-specific release and adaptive mechanical properties [7, 15].By utilizing patient-specific anatomical data, 4D printing enables fabrication of bespoke delivery devices that synchronize drug-release kinetics with individual physiological needs [27,28]. Challenges regarding regulatory approval, material biocompatibility, and large-scale manufacturing are also addressed [20,21,24]. Ultimately, 4D printing represents the next frontier in achieving truly personalized pharmaceutical care [29].