Colorimetric Chitosan Films with Tunable Drug Release Ratio: Effect of Citric Acid and Acetic Acid Concentration Ratio and Drying Temperature.

This study successfully controlled the mechanical structure of chitosan films by regulating the interactions between chitosan molecules through variations in the concentration ratio of citric and acetic acids within the films. Additionally, precise drug release was achieved by adjusting the drying temperature during the synthesis. The key issue addressed is the challenge of achieving precise drug release control in biodegradable materials. Inaccurate drug release can lead to ineffective treatment or adverse side effects, limiting therapeutic efficacy and increasing healthcare challenges. The main objective was to fine-tune the films' composition and mechanical properties to achieve predictable control over drug release ratios. Our results show that increasing the concentration of citric acid enhanced the drug release ratio, while higher drying temperatures reduced the release ratio, likely due to structural changes in the film. Furthermore, structural changes in the chitosan films caused by varying the concentration ratio of citric acid to acetic acid enabled the successful control of the tensile strength and strain of the films. Additionally, we developed films capable of visually indicating the drug release ratio through color changes before and after release, providing a simple and effective method for real-time monitoring. Despite these promising results, challenges remain, such as improving the biocompatibility of films for use in complex biological environments. Future research will focus on enhancing durability, conducting further tests in biological systems, and exploring methods to increase the biocompatibility of films and their long-term performance.