Design of an Emulgel-Type Cosmetic with Antioxidant Activity Using Active Essential Oil Microcapsules of Thyme (Thymus vulgaris L.), Cinnamon (Cinnamomum verum J.), and Clove (Eugenia caryophyllata T.)

Essential oils (EO) are complex mixtures of biosynthesized chemicals basically by plants, which provide them their characteristic aroma. Many have biologically recognized activities as antioxidants and anti-inflammatory among others, and many of them are employed as cosmetic actives. Very often, these properties are not fully exploited because of their high volatility and tendency to oxidize, so it is necessary to attach them to a conveyor to provide them adequate stabilization and lifetime. One of the best alternatives to carry out this is microencapsulation, for which natural biopolymers can be used, such as the starches. Therefore, it used EO of thyme, cinnamon, and clove, which were obtained by conventional and assisted hydrodistillation by microwave radiation from the plant material. The chemical composition was evaluated by gas chromatography/mass spectrometry (GC/MS). The radical scavenging ability was determined by antiradical activity techniques including DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis-(3-ethylthiazoline-benzenesulfonic acid-6)), and the ORAC method was used for determining the antioxidant capacity. Also, starches of yam (D. rotundata), sweet potato (I. batatas), corn (Z. mays), and cassava (M. esculenta) were used, which were subjected to hydrolysis and lipophilization processes using dodecenyl succinic anhydride (DDSA); this chemical process achieves a significant increase in emulsifier capacity (surfactant) compared to its native state; that of cassava was the most promising starch which was used as an EO microencapsulating agent. Finally, from the EO microcapsules, an emulgel-type cosmetic was designed which maintained its antioxidant activity. The results of this work contribute to the development of stable and functional cosmetic formulations of essential oils, emphasizing that the extraction of EO by assisted microwave radiation hydrodistillation is considered a fast, efficient, green, and relatively economical method compared to conventional hydrodistillation.