Vol. 7, Issue 1, Part B (2025)

Chitosan nanoparticles (CNPs) have emerged as a promising vehicle in topical drug delivery systems due to their unique physicochemical properties, including biodegradability, bioadhesion, and ability to modulate skin permeability. With the skin acting as a formidable barrier, delivering therapeutic agents effectively through topical application remains challenging, particularly for drugs requiring deeper penetration. Chitosan, a biopolymer derived from chitin, is well-regarded for its natural biocompatibility and positive surface charge, which enhance its adhesion to negatively charged skin surfaces. These characteristics make CNPs suitable for carrying and releasing bioactive compounds in a controlled manner, thus improving drug retention and bioavailability. Recent advancements in nanoparticle synthesis methods, such as ionic gelation and emulsion-solvent evaporation, have further enabled the production of CNPs with optimized size, stability, and encapsulation efficiency, all of which are critical for enhancing skin permeability.
In topical applications, CNPs facilitate drug penetration by interacting with the lipid bilayer of the stratum corneum, temporarily altering its structure to allow for deeper permeation of active agents. The bioadhesive nature of chitosan further allows for prolonged drug residence time on the skin surface, making CNPs especially advantageous for sustained release formulations. The enhanced penetration capability of CNPs has opened new avenues for delivering a range of therapeutic agents, including anti-inflammatory compounds, antioxidants, antimicrobials, and even chemotherapeutics for localized treatment of skin cancer.