| description abstract | Abstract. Inflammatory bowel disease requires engineered systems that can stay stable in the upper gastrointestinal tract and activate only when they reach the colon. In this study, we developed a bioresponsive polymer system using pH-responsive and hydrophobic Eudragit® polymers to create colon-activated Mesalazine microspheres. The microcarriers were produced through an aqueous spray-drying process and evaluated for their structure, stability, and functional response in simulated gastric, intestinal, and colonic environments. They remained stable under acidic and near-neutral pH, releasing less than 25% of the drug in the first 6 h. At colonic pH, the polymer matrix ionized and swelled, triggering a complete and controlled release of Mesalazine. Structural and molecular analyses (scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray diffraction) confirmed the formation of a stable co-amorphous drug–polymer network with smooth and uniform particle morphology. Overall, this work demonstrates a bioengineered pH-responsive system capable of protecting Mesalazine during gastrointestinal transit and releasing it selectively at the site of inflammation, offering a safe and scalable platform for colon-targeted inflammatory bowel disease therapy. | |
