Development and Physicochemical Characterization of Oil-in-Water Cosmetic Creams Containing Vaccinium vitis-idaea (Lingonberry) Fruit Extract

The purpose of this investigation was to develop and physicochemically characterize two natural O/W cosmetic cream prototypes (LC1, LC2) containing 5% (w/w) of a Vaccinium vitis-idaea (lingonberry) fruit extract (LE) together with their corresponding blank formulations (LC1-BL, LC2-BL). The extract was obtained by hydroalcoholic maceration followed by solvent removal and was characterized for total phenolic, flavonoid, and monomeric anthocyanin content. Its antioxidant capacity was evaluated using DPPH, FRAP, CUPRAC, and ABTS assays. The phenolic profile was further explored by HPLC–DAD–ESI(+), enabling tentative identification of phenolic subclasses previously reported in the literature to be associated with antioxidant properties. The prepared creams were evaluated for qualitative organoleptic properties, pH, texture (hardness, adhesiveness, and spreadability), viscosity, and accelerated conditions of stability. All formulations were stable, and no phase separation occurred; however, the addition of the extract modified their color and odor and decreased the pH to values within the physiological skin pH range. An in-silico safety evaluation of the constituents (MoS and TTC) found a good toxicological profile at concentrations employed. Overall, the results support the feasibility of incorporating lingonberry fruit extract into O/W cosmetic cream systems and demonstrate that appropriate formulation design allows the development of stable products with defined physicochemical and mechanical characteristics.