CONTROLLED DRUG DELIVERY SYSTEMS: A COMPREHENSIVE REVIEW OF RECENT ADVANCES, CHALLENGES, AND FUTURE DIRECTIONS

Abdul Wadood Ansari*, Abhisek Yadav , Indrakesh Prajapati and Sapna Yadav

ABSTRACT

Controlled drug delivery systems (CDD S) represent a significant advancement in the field of pharmaceutical sciences, aiming to deliver therapeutic agents at a predetermined rate for a specified period, thereby maximizing therapeutic outcomes while minimizing adverse effects. Over the past few decades, CDDS have transitioned from conventional formulations to highly sophisticated, targeted platforms utilizing smart materials and innovative engineering techniques. This comprehensive review explores recent progress in CDDS, encompassing polymer ba sed carriers, lipid based vesicles, nanoparticles, nanosponges, hydrogels, and implantable systems. Emerging technologies such as stimuli responsive systems triggered by pH, temperature, enzymes, or magnetic fields and bioresponsive carriers for site speci fic release are also discussed. Furthermore, the review critically examines the formulation strategies, pharmacokinetic benefits, and clinical translation of these systems, along with the technological, regulatory, and scalability challenges that hinder th eir widespread adoption. Particular attention is given to the integration of CDDS with digital health tools, biosensors, and artificial intelligence, which are paving the way toward personalized and precision drug delivery. Despite the notable progress, hu rdles such as drug degradation, limited bioavailability for certain APIs, immunogenicity, and high production costs remain critical concerns. The paper concludes by highlighting future directions, including advances in nanotechnology, 3D printing, and resp onsive biomaterials, which hold immense potential for the next generation of CDDS. Overall, this review provides a robust foundation for understanding the current landscape, unresolved challenges, and forward looking innovations in controlled drug delivery

Keywords: Controlled raelease, Nanoparticle, Diffusion controlled release.