Innovative Gel Formulation Incorporating Vernonia amygdalina Leaf Extract Nanoparticles: Physical Evaluation and Moisturizing Potential

Vernonia amygdalina exhibits relatively weak antioxidant activity with an IC50 value greater than 200 ppm. This study aimed to evaluate the formulation of Vernonia amygdalina leaf extract nanoparticle (NEDA) to enhance the absorption and stability of its active compounds in a gel preparation intended for use as a moisturizer. The NEDA was formulated using chitosan and NaTPP with the following compositions: F1 (1:10:1), F2 (1:15:1), and F3 (1:20:1). The concentrations of NEDA incorporated into the gel formulations were prepared in four variations: G0 (0%), G2 (5%), G2 (10%), and G3 (15%) using nanoparticles from the optimized F3 formula, with Carbopol employed as the gelling agent. The evaluation conducted on the formulations included particle size, particle morphology, organoleptic properties, homogeneity, viscosity, pH, spreadability, adhesiveness, moisturizing effect, and stability. The result showed that the particle size of NEDA F1, F2, F3 were 343±26.87 nm, 121.5±4.94 nm, and 81.5±0.70 nm, respectively. Transmision Electron Microscopy (TEM) revealed that the nanopartcile exhibited spherical morphology. The antioxidant activity evaluated using the DPPH method showed the IC50 of 194±0.86 ppm for the crude extract (EDA), whereas NEDA F3 demonstrated a stronger antioxidant activity with an IC50 value of 124.5±0.67 ppm. The organoleptic testing indicated that the NEDA gel formulations G0, G1, and G2 were clear, while G3 appeared slightly cloudy; all formulas were homogeneous. The viscosity testing showed that the G0-G3 formulations ranged between 35000-49000 cP. The pH values of the gels were within the normal skin pH range (4,1-5,1). The spreadability and adhesiveness tests revealed values ranging from 4,5-5,2 cm an 3,7-4,8 seconds, respectively. The moisturizing effect evaluation performed on G2 demonstrated an increase in skin moisture from 40% to 47% after 2 hours of application. In conclusion, the NEDA gel formula G2 was determined to be the most optimal. No significant differences were observed in the physical evaluation parameters during 28 days of storage (P=0,220), indicating good formulation stability.