Nanoemulsions Using Sustainable NaDES-Based Tobacco Waste Extracts for Cosmetic Applications

Demand for cosmetics based on green production and the circular economy is growing. The inflorescences and apical leaves of Nicotiana tabacum (tobacco) after blunting, deflowering, or topping are considered pre-harvest waste biomass. Using green and ecofriendly solvents such as natural deep eutectic solvents (NaDESs) offers a sustainable way to make use of this biomass for incorporation in cosmetic formulations. The inflorescence and apical leaves of tobacco var Virginia were therefore dried, powdered, and extracted using a NaDES composed of choline-chloride, urea, and distilled water (NaDES CU). The resulting inflorescence and apical leaves extracts showed high concentrations of phenolic compounds and flavonoids. Both extracts demonstrated significant biological activity and effectively inhibited tyrosinase, the enzyme responsible for melanin regulation and skin aging (IC50 = 50 μg GAE/mL), as well as showing antioxidant capacity (ABTS•+; SC50 =1.7–7 μg GAE/mL). Ten nanoemulsions containing tobacco leaf- and inflorescence extract-based NaDES CU, formulated using different polysorbates, deionized water and glycerin, were produced. A low-energy emulsification technique at a constant temperature was applied. Considering the droplet size and polydispersity index, only the nanoemulsions containing inflorescence and leaf extracts based on NaDES CU and containing 5% or 10% polysorbate 85 were selected for further stability assessment and characterization. This study highlights the potential of NaDES combined with tobacco waste extracts as a sustainable and non-toxic ingredient in anti-aging and antioxidant cosmetics.