This study investigates the enhancement of mucoadhesive properties of gelatin through chemical modification with unsaturated anhydrides (crotonic, itaconic, and methacrylic). The modified gelatins, named Gel-CA, Gel-IA, and Gel-MA, were synthesized by reacting gelatin with these anhydrides at varying molar ratios. The successful synthesis was confirmed using 1H NMR, FTIR spectroscopies, and colorimetric TNBSA assays. The isoelectric points (IEPs) of the modified gelatins were studied using viscosity and electrophoretic mobility measurements, and the thermoreversible gelation points were determined through rheological studies. The toxicological properties of the modified gelatin derivatives were assessed using an in vivo slug mucosal irritation test (SMIT) and an in vitro MTT assay with human pulmonary fibroblasts. Two model dosage forms, physical gels and spray-dried microparticles, were prepared and their mucoadhesive properties were evaluated using ex vivo porcine vaginal and sheep nasal mucosae. The results showed that the modified gelatins exhibited superior mucoadhesive properties compared to native gelatin, attributed to the formation of covalent bonds with cysteine-rich subdomains in mucin through thiol-ene click Michael-type addition reactions. The modified gelatins were found to be safe and suitable for further development in pharmaceutical applications.This study investigates the enhancement of mucoadhesive properties of gelatin through chemical modification with unsaturated anhydrides (crotonic, itaconic, and methacrylic). The modified gelatins, named Gel-CA, Gel-IA, and Gel-MA, were synthesized by reacting gelatin with these anhydrides at varying molar ratios. The successful synthesis was confirmed using 1H NMR, FTIR spectroscopies, and colorimetric TNBSA assays. The isoelectric points (IEPs) of the modified gelatins were studied using viscosity and electrophoretic mobility measurements, and the thermoreversible gelation points were determined through rheological studies. The toxicological properties of the modified gelatin derivatives were assessed using an in vivo slug mucosal irritation test (SMIT) and an in vitro MTT assay with human pulmonary fibroblasts. Two model dosage forms, physical gels and spray-dried microparticles, were prepared and their mucoadhesive properties were evaluated using ex vivo porcine vaginal and sheep nasal mucosae. The results showed that the modified gelatins exhibited superior mucoadhesive properties compared to native gelatin, attributed to the formation of covalent bonds with cysteine-rich subdomains in mucin through thiol-ene click Michael-type addition reactions. The modified gelatins were found to be safe and suitable for further development in pharmaceutical applications.