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

Nanoemulsions loaded with Ascorbyl Palmitate were prepared and incorporated into Carbopol & REG; Ultrez hydrogels. The nanoemulsions presented diameter (200 nm & PLUSMN; 4.02), polydispersion index (0.186 & PLUSMN; 0.021, zeta potential (-12 mV & PLUSMN; 2.14), pH (3.61 & PLUSMN; 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 & PLUSMN; 8.21), polydispersity index (0 0.2 & PLUSMN; 0.01), pH (3.5 & PLUSMN; 0.26), spreadability (3.96 & PLUSMN; 0.13 mm2.g � 1) and viscosity (9253 & PLUSMN; 2130 mPa.s). Antioxidant activity tests showed that the hydrogels kept under refrigeration had their antioxidant activity preserved for 30 days (10 & mu;Mol TE/& mu;L (DPPH) and 10.4 & mu;Mol TE/& mu;L (ABTS)), while the nanoemulsions showed a reduction (values lower than 5 & mu;Mol TE & mu;L) after 30 days. The hydrogels maintained the antioxidant activity of Ascorbyl Palmitate.