Study of Formulation, Physical Properties, and Instability Process and In Vitro Evaluation of Transparent Nanoemulsions Containing Sesame Seed Oil (SO) and Raspberry Seed Oil (RO)

Nanoemulsions are significant for cosmetic products intended for skin care and for health products due to the reduced size (range 20 to 500 nm) of the globules, which avoids processes of instability. They present transparency, fluidity, wettability, and spreadability; increase skin penetration; and have good sensation. The main instability mechanism of nanoemulsions is called Ostwald ripening, responsible for increasing the average diameter of emulsion globules. Sesame Seed Oil (SO) and Raspberry Seed Oil (RO) are indicated as moisturizing agents recently used in the cosmetic industry and for reducing transepidermal water loss, preventing damage to the skin barrier. They contain specific compounds with common properties such as antioxidant, moisturizing, emollient, and photoprotective actions, making them attractive alternative and complementary treatments to soften the process of skin aging. Below, we present the results of this research on the development of nanoemulsions containing Sesame Seed Oil added with Raspberry Seed Oil by the low-energy method. SO nanoemulsions at HLB = 8.0 were obtained with PEG 15 castor oil (A) and PEG 30 castor oil (F.80) and had globule sizes of 50 nm and 200 nm, respectively, along with pH values considered suitable for skin care products and lower viscosity values allowing for the easy application of nanoemulsions to the skin. Nanoemulsions A and F.80 showed antioxidant activities of 68.71% and 67.75%, respectively. SO nanoemulsions with PEG 15 and PEG 30 castor oil were obtained at 85 °C and 75 °C, respectively, and have the lowest Ostwald ripening index (1.33 × 1022 m3 s−1). The in vitro evaluation conducted using the HET-CAM method for nanoemulsions and PEG 15 and PEG 30 castor oils showed that they were slightly irritating and could be used in cosmetic products.