Abstract
Polysaccharide-based films are widely studied as topical systems due to their biocompatibility and tunable structural properties. In this study, composite films based on agar–chitosan (A-series) and gellan–chitosan (G-series) were developed with naringin as a bioactive component. The effects of polymer composition and naringin loading on structural organization, swelling behavior, antibacterial activity, and biocompatibility were evaluated. The results show that agar-based systems exhibited significantly higher swelling (~1370%), indicating a more open and highly hydrated structure, whereas gellan-based films formed more compact networks with moderate swelling (~347%). The incorporation of naringin (0.25 g per formulation) led to a pronounced increase in swelling in gellan-based systems (~777%), suggesting reduced network density, while only a slight effect was observed for agar-based films (~1444%). Antimicrobial studies against Staphylococcus aureus confirmed activity in both systems. The gellan-based formulation showed increased antibacterial activity with higher naringin loading (up to 30.0 ± 0.0 mm), whereas agar-based systems demonstrated maximum activity at lower naringin content (27.67 ± 0.58 mm). These findings indicate that antibacterial performance is influenced not only by the amount of bioactive compound but also by matrix structure and release characteristics. In vivo studies of selected A-series samples confirmed good tolerability of the naringin-loaded film (A1N1), with no signs of systemic toxicity or skin irritation, while anti-inflammatory activity under acute conditions was limited. Overall, the developed polysaccharide-based films show potential as topical systems; however, further optimization of polymer composition and formulation parameters is required to achieve a balance between structural stability and biological performance.