N-Trimethylchitosan is widely used in drug delivery systems due to its enhanced solubility and mucoadhesive properties. It is particularly effective in nasal, oral, and ocular delivery, where it improves the absorption of drugs by opening tight junctions between epithelial cells. Its positive charge allows it to interact strongly with negatively charged mucosal surfaces, prolonging residence time and increasing bioavailability. It is also employed in gene delivery, where it helps condense DNA and protect nucleic acids from degradation. Additionally, it shows antimicrobial activity, making it useful in wound healing and antimicrobial coatings. Its biocompatibility and biodegradability make it suitable for various biomedical and pharmaceutical applications.