In vitro antioxidant and cytotoxic activity of nanostructured formulations containing Ascorbyl Palmitate

Nanoemulsions loaded with Ascorbyl Palmitate were prepared and incorporated into Carbopol® Ultrez hydrogels. The nanoemulsions presented diameter (200 nm ± 4.02), polydispersion index (0.186 ± 0.021, zeta potential (−12 mV ± 2.14), pH (3.61 ± 0.02), spherical morphology and active content (1 mg/mL). Cytotoxicity tests showed that the decrease in cell viability (VERO cells and 293T Fibroblasts) was dose-dependent. The hydrogels showed satisfactory organoleptic characteristics, diameter (226 nm ± 8.21), polydispersity index (0 0.2 ± 0.01), pH (3.5 ± 0.26), spreadability (3.96 ± 0.13 mm2.g−1) and viscosity (9253 ± 2130 mPa.s). Antioxidant activity tests showed that the hydrogels kept under refrigeration had their antioxidant activity preserved for 30 days (10 μMol TE/μL (DPPH) and 10.4 μMol TE/μL (ABTS)), while the nanoemulsions showed a reduction (values lower than 5 μMol TE μL) after 30 days. The hydrogels maintained the antioxidant activity of Ascorbyl Palmitate.