The aim of this study was to develop and evaluate a more effective mucoadhesive thiomer for prolonged applications. Therefore, 2-iminothiolane was covalently attached to chitosan backbone. Following, a preactivation step followed, mediated by 6,6´dithionicotinamide (6,6-DTNA), thiol groups were modified by disulfide bonds formation. Mucoadhesion studies were performed on mucosa. Additionally, water binding capacity, disintegration and cytotoxicity studies were accomplished. Chitosan-thiobutylamidine-mercaptonicotinamide (Ch-TBA-MNA) displayed 1.8-fold higher stability and 1.6-fold higher mucoadhesive properties, respectively. Due to these results preactivated thiomers exhibits an improved stability and enhanced mucoadhesive properties. Therefore, preactivated chitosan seems to be advantageous administrations with prolonged residence time compared to corresponding thiomers and chitosan.