Drug Delivery Systems: An Overview of Conventional and Modern Approaches

This review provides an overview of conventional and modern drug delivery systems and their role in improving therapeutic effectiveness. The paper discusses the evolution of drug delivery technologies, traditional administration routes, controlled-release formulations, and advanced delivery platforms including liposomes, polymeric nanoparticles, solid lipid nanoparticles, hydrogels, and micelles. Their applications in cancer therapy, vaccine delivery, infectious diseases, neurological disorders, and chronic disease management are also highlighted. The review aims to provide undergraduate and early graduate students with a broad introduction to the principles and pharmaceutical significance of modern drug delivery systems.