Modern Approaches in Targeted Drug Delivery Systems: Types, Carriers, Recent Advances, and Future Prospects

Abstract

Conventional drug delivery approaches face challenges such as poor biodistribution, lack of target specificity, and systemic side effects, emphasizing the necessity for delivery systems that precisely deliver drugs to affected tissues while reducing exposure to nearby healthy organs. Targeted drug delivery systems (TDDS) have been recognized as a potential approach to enhance therapeutic effectiveness while reducing the systemic toxicity attributed to conventional drug delivery. This review presents a brief overview of the basic principle and current advancements in TDDS, highlighting localized drug delivery, targeted delivery approaches, and the role of specialized transport systems. Major carrier systems including liposomes, niosomes, dendrimers, nanoparticles, and monoclonal antibodies are discussed together with passive, active, and stimuli-responsive targeting approaches. This study focuses on the significance of the enhanced permeability and retention (EPR) phenomenon in passive targeting and ligand-receptor interactions in active targeting. Emerging technologies like magnetic microrobots and quantum dots exhibit promise for overcoming biological barriers, facilitating precise delivery alongside simultaneous imaging. Although there is significant progress, limitations such as tumor heterogeneity, biological barriers, formulation complexity, and regulatory requirements continue to constrain the broad clinical application of TDDS. Further investigations should focus primarily on the development of precise, tailored, versatile, and clinically scalable distribution systems to enhance therapeutic efficacy.