DESIGN AND EVALUATION OF STIMULI-RESPONSIVE SUSTAINED RELEASE DRUG DELIVERY SYSTEMS FOR SITE-SPECIFIC THERAPY

Anant Kumar*, Nawaz Alam, M. D. Saif, Dayanand Hans, Raju Nand Hans, MD. Shakir Alam

Stimuli-responsive drug delivery systems (DDS) have emerged as advanced platforms for achieving controlled, sustained, and site-specific therapeutic effects. These intelligent systems respond to internal and external stimuli such as pH, temperature, enzymes, and redox conditions, enabling precise drug release at the target site. The present review provides a comprehensive overview of the design strategies, formulation approaches, and evaluation parameters of stimuli-responsive sustained release drug delivery systems. Various carriers including polymeric nanoparticles, hydrogels, nanogels, and liposomal systems have been explored to improve drug loading efficiency, stability, and release control. Formulation techniques such as nanoprecipitation, emulsion solvent evaporation, and polymerization play a critical role in determining system performance. Key evaluation parameters including particle size, zeta potential, drug loading, and in vitro drug release are essential for assessing effectiveness, while kinetic models provide insight into release mechanisms. These systems offer significant advantages such as enhanced targeting, reduced systemic toxicity, and improved therapeutic outcomes. However, challenges related to scalability, stability, and clinical translation remain. Overall, stimuli-responsive sustained release systems represent a promising and evolving strategy for advanced site-specific therapy.[1]