Background Essential oils have great interest among the increasing demand for herbal cosmetics in the market. They are natural sources of biologically active ingredients due to the wide application of such compounds as well as their particular chemical composition. Several researches have evaluated the effectiveness of these bioactive ingredients for use in cosmeceuticals, mainly in both hair scalp and shaft hair damage repair. Thus, the amounts and their associations define the properties of these compositions with interest for hair cosmetic use, such as antioxidant, inflammatory, and antimicrobial activities. Because they are complex compounds, their actions on the skin, hair scalp, and shaft are not yet fully understood. Aims The purpose of this review is to highlight the relevant researches and findings on essential oils in hair care. Methods In order to achieve this objective, the present work comprises an updated bibliographic review related to essential oils used in hair care. Results It was possible to observe that cosmeceuticals containing essential oils applied to the scalp are preferable for topical activity. Also, it was noticed that there are few reports regarding their use in hair shaft. However, it was found that some oils are used to intensify the brightness and fix the hair color. Conclusions This work demonstrated that the use of essential oils in both cosmetic products (industrial application) and those associated with oils carriers (as individual protocols) may lead to satisfactory results in the treatment of some scalp dysfunctions.

Summary Background Hair‐straightening treatments may involve the use of thermal devices, which potentially cause damages in the cuticle and cortex of the hair fibers. Particularly, the heat causes denaturation of the α‐keratin and the degradation of the components of the hair cortex. Objectives The aim of this study was to evaluate the effect of heating on the cuticle and cortex of the Caucasian and Asian virgin hair by using heat iron flat. Methods The effects of the heating in the tresses of Caucasian and Asian virgin hair were analyzed by thermogravimetry/differential scanning calorimetry‐Fourier transform infrared/mass spectrometry (TG/DSC‐MS/FTIR), protein loss analysis (PLA), Fourier transform infrared (FTIR‐ATR), and scanning electron microscope (SEM). Results TG/DSC‐MS/FTIR results were: formation of the H2O between 25‐170°C and CO2, SCO and H2S from 200°C. Denaturation temperature = 237°C. Protein loss: Asian hair>Caucasian hair. Data presented statistically significant alterations, α = 5, P ≤ 0.05, n = 3. FTIR‐ATR: changes in the secondary structural conformation of the protein of hair cuticle. SEM: heat caused damage to hair cuticle. Conclusions The results evidenced the importance of the control of temperature in the procedures involving heat. The damage caused by thermal devices showed be dependent of the ethnicity analyzed (Caucasian and Asian hair).

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In view of the increase in the number of cosmetic preparations containing antioxidant vitamins, chiefly, due to their action in preventing the process of skin aging, there is a need to develop pre-formulation studies and to validate analytical methods in order to obtain high quality products. Thus, the objective of this research was to evaluate and compare the thermal behavior of tocopheryl acetate and ascorbyl tetraisopalmitate as raw materials, and incorporated into a base cream. Thermogravimetry (TG / DTG) and differential scanning calorimetry (DSC) were used for this purpose. Both vitamins were found to be stable up to 250ºC. The base cream (placebo) and the sample (base cream containing the vitamins) presented different weight loss. Thermal analysis has shown itself to be an excellent tool for the characterization of these vitamins and can be used in routine analysis for quality control of this type of cosmetic formulation.Uniterms: Thermal analysis. Cosmetic emulsion/qualitative analysis. Cosmetics/quality control. Tocopheryl acetate/antioxidant action. Ascorbyl tetraisopalmitate/antioxidant action. Vitamins/use in cosmetics.Considerando o potencial antioxidante das vitaminas utilizadas em produtos cosméticos, seu uso na prevenção do processo de envelhecimento da pele e a necessidade de estudos de pré-formulação que garantam o desenvolvimento de cosméticos de qualidade, foi objetivo deste trabalho avaliar e comparar o comportamento térmico dos ativos acetato de tocoferila e tetraisopalmitato de ascorbila, matérias-primas, isoladamente e incorporados em creme base. As técnicas termogravimetria/termogravimetria derivada (TG/DTG) e calorimetria exploratória diferencial (DSC) foram utilizadas para tal finalidade. Verificou-se que as vitaminas mantiveram-se estáveis até a temperatura de, aproximadamente, 250 ºC, observando-se diferença na perda de massa entre o creme base e o creme base associado às vitaminas. Assim sendo, a análise térmica mostrou-se como excelente ferramenta para caracterização das vitaminas e do creme base, podendo ser empregada em análises de rotina no controle de qualidade deste tipo de formulação cosmética.Unitermos: Análise térmica. Emulsão cosmética/análise qualitativa. Cosméticos/controle de qualidade. Acetato de tocoferila/potencial antioxidante. Tetraisopalmitato de ascorbila/ potencial antioxidante. Vitaminas/uso em cosméticos.