Review of Chitosan-Coated Nanoscale Liposomes for Enhanced Drug Delivery

Chitosan-coated nanoscale liposomes represent a versatile platform for overcoming the major limitations of conventional liposomes, including instability, rapid clearance, poor mucoadhesion, and limited targeting ability. This review highlights the mechanistic role of chitosan as a surface modifier, which improves colloidal stability, enhances mucoadhesion, prolongs systemic circulation, facilitates immune evasion, and enables functionalization with targeting ligands. Key coating strategies are compared, with emphasis on ex situ methods such as layer-by-layer assembly, ionic cross-linking, and electrostatic deposition, as well as emerging in situ approaches that offer scalability and integration into liposome formation. Analytical tools, including DLS, zeta potential, NTA, TRPS, FT-IR, NMR, DSC, TGA, and microscopy, are critically discussed for their roles in confirming coating efficiency, stability, and functional performance. Applications of chitosan-coated liposomes in oral delivery, sustained release, oncology, mucosal vaccination, and anti-inflammatory therapy demonstrate their broad therapeutic potential. Finally, challenges such as scalability, reproducibility, size control, and regulatory considerations are outlined, along with future directions toward standardized protocols and clinically translatable systems. Overall, this review consolidates current knowledge to support the rational design and advancement of chitosan-coated liposomal formulations as next-generation drug delivery platforms.