Testing the Activity of Nanochitosan Hydrogel Containing Earthworm (Lumbricus rubellus) Extract as a Future Anti-Aging Candidate

Background: Premature aging is a skin problem influenced by exposure to solar radiation and the formation of Reactive Oxygen Species (ROS). Accumulation of ROS can cause oxidative stress, leading to skin damage such as dryness, loss of elasticity, and wrinkles. Earthworm (Lumbricus rubellus) extract contains flavonoids, alkaloids, and tannins, which have potential antioxidant activity. Formulation in the form of a nanitosan hydrogel is expected to support the delivery of active compounds into the skin. Objective: This study aimed to analyze the antioxidant activity of Lumbricus rubellus extract and evaluate the physical characteristics and stability of nanitosan hydrogel as an anti-aging candidate. Methods: The extract was obtained by maceration using 70% ethanol. Phytochemical screening was conducted for flavonoids, alkaloids, and tannins. Antioxidant activity was evaluated using the DPPH method at concentrations of 20–100 µg/mL and determined based on the IC₅₀ value. The extract was then formulated into nanitosan hydrogel at concentrations of 2.5%, 5%, and 7.5%, followed by evaluation of organoleptic properties, homogeneity, pH, spreadability, viscosity, and irritation. Results: The extract yield was 34.3% and contained flavonoids, alkaloids, and tannins. The IC₅₀ value of the extract was 95.44 ppm, indicating strong antioxidant activity. The preparations showed good homogeneity and organoleptic stability, with a pH range of 6.6–6.8 and viscosity of 28,000–32,000 cps. Visual observation showed no apparent signs of irritation. Conclusion: Lumbricus rubellus extract demonstrated strong antioxidant activity and could be formulated into nanitosan hydrogel with good physical characteristics, indicating its potential for further development as an anti-aging preparation.