Chitosan-based hydrogels: A comprehensive review of transdermal drug delivery

This article provides a comprehensive review of chitosan-based hydrogels for transdermal drug delivery. It covers various aspects including the chemical structure of chitosan and its derivatives, crosslinking agents, hydrogel morphology, and drug loading and release behaviors. The review draws on 16 studies sourced from Scopus, focusing on how the composition and structure of hydrogels influence drug release. The chemical structure of chitosan and its derivatives, such as chitosan hydrochloride and quaternary ammonium chitosan, plays a crucial role in determining the mechanical properties and stability of hydrogels. Crosslinking agents, both chemical and physical, affect the hydrogel's strength and transparency as well as its drug release profile. Hydrogel morphology, including its porosity, significantly impacts drug loading capacity and release behavior. Hydrogel-based microneedles show potential in overcoming the limitations of traditional drug administration methods by enhancing skin penetration and drug loading efficiency. Additionally, factors such as swelling ratio, drug loading efficiency, and release behavior are influenced by crosslinking methods, material composition, and environmental conditions. This article concludes that the design and modification of chitosan-based hydrogels can optimize transdermal drug delivery by improving drug release profiles and stability.