Chitosan/Gelatin/Nanocellulose-Based System for Ophthalmic Drug Delivery

This study outlines the development of a chitosan/gelatin biopolymer-based ophthalmic drug delivery film, crosslinked by nontoxic citric acid with enhanced mechanical properties attributed to nanocellulose particle reinforcement. Dynamic light scattering analysis indicates the formation of nanocellulose particles with an average diameter of 177.9 nm. Tensile test demonstrates increased strength with the incorporation of nanocellulose (NC) particles from 0 to 1%. UV-transmission analysis indicates a reduction in light transmission by incorporating NC. Puncture test results reveal that 1% NC incorporated sample showed higher puncture force (9.5 kN) and higher toughness than 0% NC incorporated film (7.5 kN). Thermal analysis revealed higher weight reduction (66.85%) of CG-0%NC film compared to CG-1%NC (63.56%) film. Water contact angle measurement indicates that the CG-1%NC film contains less hydrophilic properties than CG-0%NC film. The scanning electron microscopy (SEM) examination shows a homogeneous distribution of nanocellulose in CG film. In vitro drug release studies indicate that the CG-1%NC film shows a more controllable cumulative drug release with a 600-min equilibrium time compared to the CG-0%NC film in laboratory-made aqueous humor media. The antibacterial activity analysis indicates that the CG-1%NC-Rb film exhibits antibacterial behavior against common pathogenic bacterial species such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The film's transparency, controlled drug delivery behavior, and increased mechanical properties make it a promising candidate for an ophthalmic drug delivery system.