There are increasing demands for cosmetic emulsions with natural active components such as plant extracts because of their myriad benefits. Quality of cosmetic emulsions may be affected by distribution and storage processes, which can lead to peroxidation of lipid components. Lipid peroxidation results in undesirable alterations in efficacy, texture, and appearance of the cosmetic product, thus indicating a need to find a safe and potent compound to be added in products to postpone oxidation processes. In that sense, the current article gives an overview of parameters influencing oxidative stability of emulsions, as well as methods for assessing the oxidative stability. Emphasis is given to the usage of plant extracts rich in phenolics for improving oxidative stability of cosmetic emulsions. Application of plant extracts in cosmetic emulsion is promising because of their significant antioxidant properties which may delay lipid peroxidation during storage. Plant species are a valuable source of biologically active compounds that might be exploited in the cosmetic and pharmaceutical industry.

Colorants for cosmetics appear to be more strictly regulated than any other cosmetic ingredients. Most countries have adopted a positive regulatory system for colorants used in cosmetics. Although there have been many reports on colorants that are used in food products from regulatory perspectives, reports on colorants used in cosmetic products have been limited. The objective of this report is to provide different countries' regulatory requirements and to encourage the cosmetic industry to export products in compliance with global regulations through a comparative analysis of cosmetic colorant regulatory systems in major countries. We first provide an overview of cosmetic colorant regulatory frameworks of the European Union, the United States, China, and Korea. Then the cosmetic colorants were divided into three sectors: synthetic, inorganic, and natural. Each chapter describes the colorants' general characteristics and explains the regulatory differences. Additionally, synthetic colorant labeling with a different nomenclature system is discussed.

Scalp hair is a universal human characteristic, and a wide range of hair shape and color variations exists. Although differences in human scalp hair shape are visually apparent, the underpinning molecular insights are yet to be fully explored. This work reports the determination of differences at the protein level between two distinct groups of hair shape: very straight samples versus very curly hair samples. An in-depth highresolution liquid-chromatography mass spectrometry proteome analysis study was performed on hair samples from 50 individuals (pooled in 10 × 5 samples) with very curly hair and 50 subjects with very straight hair (pooled in 10 × 5 samples) to decipher differences between the two experimental groups at the protein level. Our results demonstrate that a distinction between the two experimental groups (very straight vs. very curly) can be made based on their overall protein profiles in a multivariate analysis approach. Further investigation of the protein expression levels between these two groups pinpointed 13 unique proteins which were found to be significantly different between the two groups, with an adjusted p-value < 0.05 and a fold change of more than two. Although differences between the very curly and the very straight hair sample groups could be identified, linkage between population differences and curl phenotype is currently unknown and requires further investigation.

This study aimed to develop a topical emulgel formulation from olive oil and lemongrass (LG) extracts and to evaluate its in vitro and in vivo (sensorial) properties in addition to its sun protection factor (SPF) value. The primary emulsion and the gel were prepared separately, and then they were levigated together to formulate the emulgel. The produced emulgel was evaluated for its physical appearance, pH, spreadability, and stability. The SPF value of emulgel was evaluated by applying the Mansur equation. Moreover, an in vivo sensorial assessment was conducted on the emulgel through a crossover study by including 20 volunteers. The results confirm good stability for emulgel formulations because there was no significant change in the pH value, no micelle inversion, or phase separation detected. The emulgel recorded a moderate SPF value (5.5) which can be useful for daily use, especially in tanned skin subjects. Moreover, the sensorial assessment of LG and blank emulgels showed a significant change in the cooling effect, odor, and smoothness and add some kind of moisture. In fact, there was a significant difference in overall properties between the two formulations where the p-value was less than 0.05. It is concluded the emulgel formulation containing LG and olive oil could be beneficial in terms of applicability and stability and can be easily formulated in pharmaceutical facilities. Besides, it would be useful for daily use because of the overall suitable properties, especially odor, feel, and SPF value.

Although traditional perm chemistry has been around for over 70 years, it still arguably remains our best means of permanently altering the shape of hair. The hullabaloo created by the so-called Brazilian keratin treatments has led to resurgence in research activities in this area-and so an overview of the incumbent technology would seem pertinent. This review highlights underlying chemistry responsible for the success of traditional thioglycolate solutions but makes the case that our knowledge gap lies with the kinetics of the process. To this end, the merits and limitations of the single-fiber tensile kinetic approach are addressed-where, despite seemingly questionable assumptions, logical outcomes are obtained from systematic experiments intended to probe the validity of this method. Furthermore, results demonstrate how considerably different rates can arise between a common perm solution and hair from different sources. It is therefore proposed that "resistant" hair is a consequence of slow reaction rates which lead to an insufficient number of cystine disulfide bonds being broken during the processing time. Additional analysis of these kinetic data suggests the presence of different mathematical models that describe the progression of the process with varying experimental conditions. The reproducibility of results and the frequency with which models arise add confidence to findings.

Subversion bias, a type of selection bias, through manipulation of subject recruitment compromises data validity. This study explores the possibility of subversion bias in sunscreen sun protection factor (SPF) testing. It has been established that subjects with lower minimal erythemal dose (MED) values exhibit higher sunscreen SPF values. Consistency of this response is determined in subjects who participated in multiple sunscreen efficacy clinical trials. All trials determined the SPF of the sunscreen standard P2. Of the 652 subjects with greater than three observations (n = 286), 35 subjects consistently had values either well above (n = 29) or below (n = 6) the average SPF value of the dataset (15.6 ± 1.2). The difference between the average SPF by the subject exhibiting the highest average SPF for P2, 19.8 ± 0.9, and the subject exhibiting the lowest average SPF for P2, 12.3 ± 2.6, is 7.5 SPF units, or 61%. Recruitment strategies based on historical SPF values for an individual would be considered subversion bias. Foreknowledge of those subjects with consistent results either in favor or not in favor of SPF testing outcomes could be exploited and would provide a reason for variation in results among testing facilities.

Luxury skin care products have emotional value because of their texture and accompanying product information. The influence of these factors appears to be linked. Here, we investigated the influence of information on brain activity during hand massages with skin care creams in healthy female volunteers. In the first session, participants received hand massages using two skin care creams (luxury and basic). In the second session, participants were shown information which indicated whether each cream was a luxury or basic product during the massage. In the third session, they received a hand massage as per the first session. Functional magnetic resonance imaging data were recorded during massages. Differential activity in the ventral striatum (VS), the caudate nucleus, and the dorsomedial prefrontal cortex (DMPFC) was significantly higher in the third session than in the first session. Moreover, differential activity in the right dorsolateral prefrontal cortex (DLPFC) was positively correlated with differential activity in both the VS and the DMPFC in the third session. These results suggest that the neural substrate of the effects is based on both the dopamine reward system and the self-other distinction system involved in social dominance and that the right DLPFC plays a critical role in the association between these systems.

Incorporating technologies such as 3D printers and the Internet of things (IoT) can improve the nail art industry by making it more efficient, and, most importantly, safer. It eliminates the need for physical shops such as nail salons. Nail art by 3D printing technology can achieve higher resolution and accuracy than before with conformal projection printing method (CPPM). The conventional method of painting nails manually leads to acute exposure to ultraviolet (UV) light that can contribute to minor health hazards. This research illustrates the benefits of using 3D printing for nail art. This study uses the IoT system, which can be stationed in a distinct location from the customer. The product on the nail is printed at least once and up to three times within 5 µm to achieve precise resolution through laser marking and CPPM, which can increase the accuracy by repeated projection to attain the required settling ratio. The correlation between the numbers of printed layers and different incident angles of the printing head on the conformal surface is discussed. The ratio of projected weight to the ideal weight for high-definition printing condition is illustrated, and comparison studies with conventional nail art techniques are conducted to validate the results.

In the present study, the required hydrophilic lipophilic balance (HLB) values of Citrus unshiu fruit oil (CUFO), Citrus unshiu peel oil (CUPO), horse fat (HF), and Camellia japonica seed oil were determined empirically by preparing oil-in-water (o/w) emulsions. Lipophilic and hydrophilic surfactants were prepared in various ratios in o/w emulsion. The droplet size of the emulsion was measured using a particle size analyzer, and the turbidity was measured using a turbidity meter and a ultraviolet (UV)-vis spectrophotometer. According to the Orafidiya-Oladimeji method, the HLB value of the emulsion having the minimum dispersion ratio, the minimum droplet size, and the maximum turbidity degree was determined as the required HLB value for each essential oil. Based on these methods, the required HLB values of CUFO, CUPO, HF, and Camellia japonica seed oil were determined as 14.75-14.90, 15.35-15.40, 6.30-7.06, and 5.94-6.30, respectively.