Formulation and Characterization of SIPI-Based Implants for Long-Term Drug Release in Chronic Disease Management

This study focuses on the formulation and characterization of Stimuli-Responsive Injectable Polymeric Implants (SIPI) for long-term drug release in chronic disease management. Chronic conditions such as diabetes, cardiovascular disorders, and neurodegenerative diseases require continuous therapeutic delivery, which traditional methods often fail to sustain due to poor compliance and fluctuating drug levels. SIPI systems offer an innovative solution by utilizing biodegradable polymers that respond to physiological stimuli—such as pH and temperature—to modulate drug release. Four formulations were developed using PLGA, PCL, Chitosan, and a PLGA-Chitosan blend. These were evaluated for physicochemical properties, thermal stability, surface morphology, biodegradation, and drug release kinetics. The PLGA-Chitosan formulation (F4) exhibited optimal performance, balancing mechanical strength, degradation rate, and controlled drug release. In-vitro studies confirmed biphasic release profiles and diffusion-controlled mechanisms as per Korsmeyer-Peppas and Higuchi models. Analytical techniques including FTIR, DSC, SEM, and HPLC validated structural compatibility and performance stability. Overall, SIPI-based implants demonstrate promising potential for site-specific, long-term drug delivery in chronic disease therapy. The results support further in-vivo investigations and clinical development of smart, patient-compliant drug delivery platforms designed to enhance therapeutic efficacy and improve quality of life in long-term treatment scenarios.