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Showing papers in "Journal of Cosmetic Science in 2018"


Journal Article
TL;DR: Fatty acid analysis indicates that BSF contains > 60% of lauric acid, which makes it less suitable for application in a skin-care product, whereas locust and cricket fats are rich in C16 and C18 fatty acids which makes them more suitable.
Abstract: Insects may provide an environmentally friendly way of producing high-quality bio-based materials that can be implemented for cosmetic applications. Insects can be bred on organic waste, in high numbers, and on small surfaces, therefore, making large scale industrial breeding possible. Fats from three insect species: the black soldier fly (BSF) (Hermetia illucens), the locust (Locusta migratoria), and the house cricket (Acheta domesticus) were evaluated for potential use in skin care. Insects were dried and fats were extracted using petroleum ether. The fats were further refined, and the fatty acid composition and the acid value were determined. The fats were used in a hand cream formulation and compared with the currently used mink-and plant-derived oils. Fatty acid analysis indicates that BSF contains > 60% of lauric acid, which makes it less suitable for application in a skin-care product, whereas locust and cricket fats are rich in C16 and C18 fatty acids which makes them more suitable. Phospholipids and free fatty acid levels in the three insect species are relatively high compared with commercial, refined oils, and need to be removed by appropriate refining protocols. Odor and color also need to be removed by physical refinement to improve the applicability.

36 citations


Journal Article
TL;DR: Investigating the cosmetic interests, public confidence in cosmetic industry, health knowledge, practice, and need for health education regarding using topical bleaching agents (TPAs) among a relatively big sample size in Al-Madinah, a conservative eastern society that acquires its social customs from Islam finds cosmetic interest is high among women using TPAs, highest among the middle age (26-40 years), and lowest among women more than 40 years.
Abstract: We aimed at investigating the cosmetic interests, public confidence in cosmetic industry, health knowledge, practice, and need for health education regarding using topical bleaching agents (TPAs) among a relatively big sample size in Al-Madinah (west Saudi Arabia, a conservative eastern society that acquires its social customs from Islam). Islamic values increased women respect and esteem in this society. This is reflected on cosmetic practices and attitude, e.g. women use face cover outdoors. This issue is vital for both women health and beauty, and is rarely discussed. TPAs use is affected by culture, social customs, and health awareness regarding TPAs chemical constituents, e.g. hydroquinone, mercury, steroids that may harm skin and general health. Ethical committee approval was done for our study that included 531 women (attending the outpatient clinics in March-April 2016) of targeted 571 (response rate was 89.8%). 43.3% (230 women) are current TPAs users. Three hundred and eight-nine women (73.3%) regularly used TPAs to heal pigmented areas like freckles (75.8%) and just to lighten skin color (58.7%). Side effects of discontinuation were restoration of normal skin color (44.3%) or even darker skin (27%), skin dryness (20%) and rash (9.6%). Mercury is recognized as harmful to human health by 30.2%, whereas cortisone was chosen by others (53.2%). Unexpectedly, minority of investigated women (10%) considered using TPAs safe and recognized harms of some ingredients as mercury whereas the majority (70.2%) does not encourage others for TPAs use although they themselves kept using TPAs for different reasons. Cosmetic interest is high among women using TPAs, highest among the middle age (26-40 years), and lowest among women more than 40 years (50% versus 17.9%) (p < 0.001). Using skin TPAs in west Saudi Arabia is comparable with international standards, higher among educated women, house wives and employed women. This denotes care of married employed women to use TPAs to express beauty to husbands. This is not reduced by work duties and is controlled by conservative Islamic modesty. Health education is mandatory regarding TPAs components and use during pregnancy and lactation. Cosmetic science and industry needs more research to improve TPAs use through providing better safe alternatives for many TPAs components, e.g. mercury and hydroquinone.

11 citations


Journal Article
TL;DR: The results showed that the SLNs can be used as a carrier for the topical delivery of Caf in a controlled manner over a 6-h period and the encapsulation efficiency was 49.22%.
Abstract: Encapsulation of active agents in solid lipid nanoparticles (SLNs) is an alternative to other controlled release systems for topical delivery. In this study, caffeine was encapsulated in SLNs to produce a delivery system with controlled release. Caffeine-loaded SLNs (Caf-SLNs) were prepared using the double emulsion method with homogenization and ultrasonication. The characterization studies were performed using dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses. The encapsulation efficiency tests were performed using UV spectrophotometry. In vitro release studies were conducted using a dialysis bag technique and high-performance liquid chromatography (HPLC) for the quantification of caffeine (Caf). The results from the DLS analysis showed that all formulations had a polydispersity index <0.3 with particle sizes <210 nm. The DSC and SEM results showed that Caf was dispersed in the SLNs. The encapsulation efficiency was 49.22%. The release studies indicated that after an initial burst at 3 min, the SLNs released Caf in a controlled manner over a 6-h period. Taken together, the SLNs can be used as a carrier for the topical delivery of Caf.

10 citations


Journal Article
TL;DR: Glutathione-loaded nanoemulsions have excellent stability, promising the solution in nano-oil droplets and are suggested for in-vivo release studies for oxidative skin related diseases.
Abstract: Glutathione reduced (GSH) is the mother of all the antioxidants and has an antimelanogenic effect. It is extremely vulnerable to oxidation in the solution form which limits its use. The GSH in nano-oil droplets present a potential solution to this problem. The aim of this study was to formulate glutathione-loaded nanoemulsion and assess its stability studies over a 90-day testing period. To formulate GSH-loaded nanoemulsion pseudo-ternary phase diagram, it was built with various concentrations of water, liquid paraffin oil, and surfactant mixture (Tween 80 and Span 80). The oily phase was prepared by dissolving the GSH (450 mg) in liquid paraffin oil through stirring. High-energy homogenization was used to prepare the nanoemulsion. From preformulation stability studies of the 28-day testing period, nanoemulsion (NE-19) with oil and surfactant mixture ratio (1:1) of hydrophilic lipophilic balance (HLB) value 10 was selected. The samples of NE-19 and its respective base (B-19) were kept at four different storage conditions for a period of 90 days and evaluated for physical characteristics, droplet size and distribution analysis, zeta potential analysis, electrical conductivity, mobility, polydispersity, pH, phase separation, and flow analysis at different time intervals. Glutathione in nano-oil droplets with nonionic surfactants produced oil-in-water nanoemulsions that were thermodynamically stable over the 90-day testing period at different storage conditions. NE-19 was formulated having non-Newtonian flow and pseudo-plastic behavior. pH was found in the range of 5-6. Polydispersity was less than 0.3. The droplet size of fresh nanoemulsion was 96.05 nm, whereas the zeta potential was -37.1. Mobility and electrical conductivity were -2.726 µm cm/Vs and 0.0141 mS/cm, respectively. Glutathione-loaded nanoemulsions have excellent stability, promising the solution in nano-oil droplets and are suggested for in-vivo release studies for oxidative skin related diseases.

10 citations


Journal Article
TL;DR: A Hamamelis virginiana leaf extract was developed that was able to restore both the balance between elastin and LOXL1 and to decrease the elafin synthesis to fight and correct the damage and became functional and aggregates of unfunctional fibers decreased.
Abstract: Photoageing, also called actinic ageing, is the main cause of prematurely aged skin. Our expertise in elastic fibers has led us to discover a process triggered in response to ultraviolet (UV) light and which upsets the balance of elastin fibers: there is too much elastin and insufficient lysyl oxidase (LOXL1) enzyme to form functional elastic fibers. This imbalance then leads to an accumulation of nonfunctional elastin, which forms aggregates. In addition to this imbalance, UV rays also induce elafin synthesis by fibroblasts. Known to be a marker of elastotic aggregates, elafin crystallizes the elastin fibers and stimulates the formation of aggregates that cannot be naturally eliminated by the skin. We developed a Hamamelis virginiana leaf extract that was able to restore both the balance between elastin and LOXL1 and to decrease the elafin synthesis to fight and correct the damage. This specific Hamamelis virginiana extract increased LOXL1 expression by twofold and decreased elafin synthesis. As a consequence, elastic fibers became functional and aggregates of unfunctional fibers decreased. The specific Hamamelis extract activity was confirmed in vivo with decreasing wrinkles and improving skin firmness.

10 citations


Journal Article
TL;DR: The reduction and 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging ability of this compound were analyzed to assess its antioxidant potential and tyrosinase inhibitory ability was analyzed to show the whitening capacity of 3-O-ethyl ascorbic acid.
Abstract: 3-O-ethyl ascorbic acid may be a good whitening ingredient in cosmetics. However, before it can be successfully used in cosmetics, its biofunctionality and stability need to be comprehensively investigated. The reduction and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability of this compound were analyzed to assess its antioxidant potential. In addition, the tyrosinase inhibitory ability was analyzed to show the whitening capacity of 3-O-ethyl ascorbic acid. Response surface methodology (RSM) was used to determine the optimal conditions for the ascorbic acid derivative in cosmetics. Based on the DPPH radical scavenging ability results, the half-inhibitory concentration (IC50) value of 3-O-ethyl ascorbic acid was 0.032 g/L. It also showed a good reducing ability at 1.5 g/L concentration. Based on the tyrosinase inhibition analysis, the IC50 value was 7.5 g/L. The optimal conditions to achieve the best stability were determined from the RSM as 36.3°C and pH 5.46.

9 citations


Journal Article
TL;DR: Overall, the niacin derivatives, more so nicotinamide and 2,6-dihydroxynicotinamide, have anti-skin aging potential through the stimulation of elastin and fibrillin, and the direct inhibition of the extracellular matrix proteolytic enzymes.
Abstract: Skin aging/photoaging is associated with altered the structure of collagen and elastin fibers, and increased activity of matrix metalloproteinases (MMP) and elastase. Nicotinamide and its derivatives, 2,6-dihydroxynicotinamide, 2,4,5,6-tetrahydroxynicotinamide, and 3-hydroxypicolinamide (collectively niacin derivatives) stimulate fibrillar collagen and heat shock proteins in dermal fibroblasts. The goal of this research was to extend the understanding of the anti-skin aging mechanism of these niacin derivatives through the stimulation of elastin (at the protein and promoter levels), fibrillin (1 and 2) in nonirradiated or ultraviolet (UVA) radiated dermal fibroblasts, and through the direct inhibition of MMP (1, 3, and 9) and elastase activities. UVA radiation stimulated elastin and inhibited fibrillin-1 and fibrillin-2 in dermal fibroblasts. The niacin derivatives significantly stimulated the expression of elastin (transcriptionally), fibrillin-1 and fibrillin-2 in nonirradiated and UVA radiated fibroblasts, and directly inhibited MMP or elastase activity. Overall, the niacin derivatives, more so nicotinamide and 2,6-dihydroxynicotinamide, have anti-skin aging potential through the stimulation of elastin and fibrillin, and the direct inhibition of the extracellular matrix proteolytic enzymes.

9 citations


Journal Article
TL;DR: It was shown that replenishment of these lipids is possible by incorporating lipids, such as fatty alcohols (FaOHs), into a gel network with anionic surfactants to create a delivery system that can efficiently penetrate FaOHs into hair and increase internal strength as measured by fatigue.
Abstract: Saturated and unsaturated fatty acids make up 85% of the total hair lipid content and are found in the cuticle and cortical cell membrane complex. Although these lipids only make up 2-6% of the hair's overall weight, they play a crucial role in keeping hair healthy, influencing shine, feel, manageability, and strength. The objective of this work was to understand the mechanisms of how these lipids are lost on exposure to external stressors, such as chemical treatments, washing, and UV exposure and to understand how their loss impacts hair strength. The experimental approach was to measure these lipids and oxidation products, lipid peroxides (LPOs) and correlate their loss with fatigue strength measurements. The results show lipids are lost over time by washing, exposure to chemical treatments, such as coloring, and environmental insults, such as UV, and it was confirmed that a mechanism of degradation is via oxidation of unsaturated lipids to form LPOs. In addition, it was shown that replenishment of these lipids is possible by incorporating lipids, such as fatty alcohols (FaOHs), into a gel network with anionic surfactants to create a delivery system that can efficiently penetrate FaOHs into hair and increase internal strength as measured by fatigue.

7 citations


Journal Article
TL;DR: Cosmetics sold in Nigeria may not add to the body burden of metals and metalloids, and the target hazard quotient, hazard index, and cancer risk were less than the acceptable limit, indicating a measure of safety.
Abstract: Twenty different brands of cosmetic products were purchased from supermarkets in Port Harcourt, Rivers State, Nigeria, with the aims to determine the levels of metals and assess the health risk to humans through long-term usage. The concentration of metals (arsenic, lead, mercury, cadmium, and nickel) in the cosmetic samples was measured with atomic absorption spectrophotometry after acid digestion. The concentration of metals in these brands of cosmetic studied ranged from As: 0.001-0.0161 mg/kg, Pb: 0.289-2.873 mg/kg, Hg: 0.001-0.0014 mg/kg, Cd: 0.001-0.334 mg/kg, and Ni: 0.007-2.748 mg/kg. The metal and metalloid contents were less than the regulatory limits set for both metal impurities and as color additives. The target hazard quotient, hazard index, and cancer risk were less than the acceptable limit, indicating a measure of safety. Cosmetics sold in Nigeria may not add to the body burden of metals and metalloids.

5 citations


Journal Article
TL;DR: A possible micro-structure of exocuticle is pointed to, hindered under usual circumstances by its heavy cross-linking and only noticeable when the absorbed moisture swells the surrounding network and annuls, in this way, its effect.
Abstract: Hair fibers were examined by atomic force microscopy, nanoindentation. By indenting along (longitudinal) and across (transversal) the fiber, we evaluated the Young's modulus and its dependence on the moisture content (relative humidity) of the environment. The ratio of the two values collected for Young's modulus, at a given relative humidity, is defined as the anisotropy index (IA) of the fiber and the acquired results give the evolution of the index of anisotropy with the relative humidity. The use of the model of composite materials allowed us to relate the anisotropy index to the fiber internal architecture. The evaluation of the results acquired on the components of the fiber, within the frame of this model, ultimately points to a possible micro-structure of exocuticle, hindered under usual circumstances by its heavy cross-linking and only noticeable when the absorbed moisture swells the surrounding network and annuls, in this way, its effect.

5 citations


Journal Article
TL;DR: It is demonstrated that most camphor essential oils on the market have a carcinogenic potential due to their high safrole levels, and n-decyl alcohol as aninternal standard is used as an internal standard.
Abstract: Safrole is a well-known carcinogenic agent that is present in camphor trees. In this study, a gas chromatographic method was established to quantitate the levels of safrole in essential oils using n-decyl alcohol as an internal standard. The method used a nonpolar column and was able to detect concentrations of safrole as low as 5 µg/ml in the samples. Following addition of 2-10 mg of safrole into 1 g of essential oil extracted from Stout Camphor wood (Cinnamomum kanehirai Hayata) or 1-10 mg of safrole into 1 g of essential oil extracted from Small-flower Camphor wood (Cinnamomum micranthum Hayat), the recovery rates of safrole were determined. With direct injection of samples into the gas chromatograph, the results showed that the recovery was more than 96.1%, with a coefficient of variation below 5.6%. We then analyzed 23 commercially available Stout Camphor and other essential oil samples and found that 21 of them contained safrole in the range of 37.65-355.07 mg/g. In addition, in the heavier essential oil distilled from Small-flower Camphor wood, the safrole level was up to 642.98 mg/g. Our results demonstrated that most camphor essential oils on the market have a carcinogenic potential due to their high safrole levels.

Journal Article
TL;DR: Asian scalp hair fibers were made thin by treatment with papain or sliced along the longitudinal axis or randomly cut by mechanical means and optical microscopic observations indicated that the medulla (M) consisted of two types of the M-surrounding cells which were linearly linked one another to form a tubular structure running through the fiber.
Abstract: Asian scalp hair fibers were made thin by treatment with papain or sliced along the longitudinal axis or randomly cut by mechanical means. Optical microscopic observations of the resulting specimens indicated that (i) the medulla (M) consisted of two types of the M-surrounding cells which were linearly linked one another to form a tubular structure running through the fiber and (ii) the drum-shaped vesicles containing small proteinous granules were neatly or sparsely stored within the tube. On the other hand, H+ and OH- ions were able to move spontaneously from one end to another through the M tube. Large molecules such as an anthocyanin dye (from purple sweet potato) were also capable of flowing through the M tube, especially rapidly when DC voltage was applied between the two ends of the hair fiber. The possible function of the M is briefly discussed in conjunction with the tubular structure and the material flow property.

Journal Article
TL;DR: Recent investigations into the transition from construction to maturation reinforce this as a key developmental threshold, where shaft production transforms from a biologically driven into a biochemically driven process, and is named "Orwin's transition."
Abstract: Research into biological manipulation of hair "quality" has ebbed and waned but today is in a resurgence. Hair appearance is regulated by multiple intervention opportunities-adding more hairs; increasing hair "amount" by modulating shaft diameter or shape; or, in principle, by altering shaft physical properties by changing its synthesis. It is likely that improved benefits may be achieved by combining multiple areas-minimizing follicle loss and miniaturization, maximizing shaft production, and treating the existing shaft. A previously overlooked opportunity is follicle metabolism: building "better" hairs. Hair production is energy intensive, and it is known that follicle metabolism influences shaft diameter. Multiphoton microscopy enables metabolic investigation of live, growing, human, hair follicles. This allows definition of multiple "zones" with vastly different metabolism: proliferation-where keratinocytes proliferate and migrate into specialized layers; production-proliferation ceases, and synthesis and patterning begin; construction and elongation-the structural framework is seeded and cells extend to create the nascent fiber; and maturation-gradual hardening and transformation into mature shaft. Recent investigations into the transition from construction to maturation reinforce this as a key developmental threshold, where shaft production transforms from a biologically driven into a biochemically driven process. We now name this "Orwin's transition."

Journal Article
TL;DR: It is suggested that emulsifiers, and not emollients, have the dominant role in determining the aesthetics of a skin care emulsion, similar to previous findings.
Abstract: The sales potential of cosmetic products is greatly determined by skin feel and skin sensory performance. To please the target audience, it is important to gather information about consumers' perception of products' sensory characteristics. In this study, six different emulsions were formulated. Samples represented three different types of emulsions, including steric-stabilized oil-in-water (O/W), liquid crystal-stabilized O/W, and water-in-oil emulsions, providing different skin feel and aesthetics. Emulsions within the same group differed in the emollients, providing similar sensory attributes. The aim was to have 50 consumers evaluate the emulsions' sensory characteristics. Using a check-all-that-apply (CATA) survey, consumers provided information about their perception of appearance, rub-out, pick-up, and afterfeel. Consumers effectively discriminated between the emulsions. Statistical analysis showed significant differences for 15 sensory attributes in the before, during, and after phases. Our findings suggest that emulsifiers, and not emollients, have the dominant role in determining the aesthetics of a skin care emulsion, similar to previous findings. The fact that untrained consumers provided similar results as trained panelists suggests the validity of the CATA survey and its reliability as a screening tool in the product development process. CATA questions may serve as a viable complimentary to descriptive sensory analysis performed by trained panelists.

Journal Article
TL;DR: Thirty-minute single application of DSM was well tolerated with short-lived moisturizing effects, which was enhanced by the presence of humectant ingredients, and with no negative impact on barrier integrity, pH, and erythema and melanin levels.
Abstract: Dead Sea mud (DSM) is commonly used by patients with various skin conditions because of its contents of healing elements. No study was published to show whether DSM application weakens or strengthens skin barrier function. In this study, we investigated the impact of 30-minute single application of various types of DSM ("As Is" mud, mud with extra Dead Sea salt, and over-the-shelf mud) on the barrier function of normal skin. The influence of 30-minute application of various types of DSM was investigated noninvasively on skin barrier properties of healthy female adult volunteers (n = 75) on predetermined circular areas. Skin hydration, transepidermal water loss (TEWL), erythema and melanin levels, and skin pH were measured directly, 30 minutes, and 60 minutes after mud removal. Thirty-minute single application of DSM was well tolerated with short-lived moisturizing effects, which was enhanced by the presence of humectant ingredients, and with no negative impact on barrier integrity, pH, and erythema and melanin levels.

Journal Article
TL;DR: In clinical evaluation, only the polyacrylate polymer produced statistically significant improvements in wrinkle size and skin firmness on the face without significant consumer use complaints such as tackiness.
Abstract: Many cosmetic polymers shrink on drying, producing a tensile force if coated on a substrate. This tensile force can be used to smoothen wrinkles and pores in facial skin. In this study, we evaluated two polymers, a polyvinylpyrrolidone (PVP) and a polyacrylate, for skin tightening properties. We conducted a double-blinded, placebo-controlled and randomized clinical study with 32 female volunteers aged 35-65 years who perceived themselves to have a loss of skin elasticity. Both polymers were formulated in a model cosmetic emulsion with hydrogenated polyisobutene as the oil phase. We measured skin firmness and tightening parameters at baseline and after each product application. Also, facial images were recorded with a fringe projection instrument. The firming measurements indicated that both polymers instantly tightened facial skin, whereas the placebo product offered no significant tightening benefit. However, in clinical evaluation, only the polyacrylate polymer produced statistically significant improvements in wrinkle size and skin firmness on the face without significant consumer use complaints such as tackiness. We concluded that skin care products using PVP and polyacrylates have the potential to offer immediate and visible benefits to consumers with aged skin.

Journal Article
TL;DR: The results showed that Caulerpa lentillifera, Sargassum crassifolium, Ulva reticulata, and Kappaphycus alvarezii are potential rich sources of protein, polysaccharide, carotenoids, and vitamins with high antibacterial, cell proliferation, moisture retention, and tyrosinase inhibitory activities.
Abstract: Seaweed is rich source of natural bioactive compounds that could be exploited as functional ingredient for cosmetic applications. The aim of this study was to evaluate the biochemical compositions and bioactivities of 10 seaweeds collected from coastal waters of Vietnam. The present study also prepared and evaluated cream mask from mixture of seaweeds extracted with water. The results showed that Caulerpa lentillifera, Sargassum crassifolium, Ulva reticulata, and Kappaphycus alvarezii are potential rich sources of protein, polysaccharide, carotenoids, and vitamins with high antibacterial, cell proliferation, moisture retention, and tyrosinase inhibitory activities. Physicochemical analysis of cream mask from a mixture of these seaweed extracts indicated that it is yellowish brown in color with a specific odor of seaweed, stable, and homogeneous for up to 12 months of storage, with a pH of 6.1, and high spread and adhesive abilities. No total aerobic mesophilic microorganisms, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and heavy metals were detected in the seaweed mask cream. The seaweed cream mask was safe and caused no irritation to normal human skin, and it satisfied provisions of Circular No. 06/2011/TT-BYT dated January 25, 2011 of the Vietnam Ministry of Health, providing cosmetic management for the cosmetic products with anti-aging and moisturizing effects.

Journal Article
TL;DR: The potential use of torsional measurements to differentiate between cosmetic treatments where other modes of deformation do not is outlined.
Abstract: To date, most single hair fiber mechanical testing publications in the literature have focused on tensile deformation with torsional measurements receiving far less attention. However, there is much to be gained from the measurement of torsional properties of a single hair fiber such as providing an insight into the shear stiffness changes that are associated with cuticle damage. This study outlines the potential use of torsional measurements to differentiate between cosmetic treatments where other modes of deformation do not. A core/shell modeling approach has also been applied to separate out the potential contributions of the cuticles and the cortex on the fiber torsional modulus and the effect of relative humidity on hair fiber structural components.

Journal Article
TL;DR: This article attempts to bridge the unproductive divide between the "dead hair" and "live follicle" worlds by summarizing both current key concepts and major open questions on how the HF, namely, the anagen hair bulb and its precortical hair matrix keratinocytes, generate the HS, focusing on selected key signaling pathways.
Abstract: For many decades, applied hair research has been hampered by an unproductive intellectual and conceptual divide between researchers who are primarily interested in the hair shaft (HS), its structural properties, visual appearance and cosmetic manipulation, and those investigators who are mainly interested in the fascinating miniorgan that cyclically regenerates the HS, the hair follicle (HF). This article attempts to bridge this unproductive divide between the "dead hair" and "live follicle" worlds by summarizing both current key concepts and major open questions on how the HF, namely, the anagen hair bulb and its precortical hair matrix keratinocytes, generate the HS, focusing on selected key signaling pathways. We discuss current theories of hair shape formation and avenues toward impacting on human HS structure. The article closes by delineating which instructive preclinical research assays are needed to ultimately close the experimental gap between HS and HF researchers in a manner that benefits consumers.

Journal Article
TL;DR: A commercially-available instrument, previously intended to visualize and quantify hair shape and volume, has been modified to measure hair motion, where visually noticeable decreases in tress motion were observed after applying small quantities of silicone oil to the hair.
Abstract: A commercially-available instrument, previously intended to visualize and quantify hair shape and volume, has been modified to measure hair motion. Specifically, a transversal motor now induces a side-to-side oscillating tress stimulus, while a video camera records the outcome. Image analysis software allows for quantifying the amount of motion (i.e. the amplitude), the shape and volume of the hair during motion, and the homogeneity of the hair (i.e. bulk -vs- flyaways). Each of these parameters has considerable dependence on the frequency of oscillation and so evaluations are carried out by systematically varying this parameter. Preliminary validation experiments are documented which involved methodical variation of parameters that were presumed to be of importance. These included the size and shape of hair tresses, various hair treatments, and environmental conditions. As a result of the sizable amount of data that results, graphical depictions provide the best means of representation. For example, amplitude -vs- frequency plots describe the extent of hair motion as a function of energy supplied to the system. Visually noticeable decreases in tress motion were observed after applying small quantities of silicone oil to the hair. This occurrence reduced the measured amplitude of tress motion, while also moving the maximum amplitude to high frequency. Accordingly, it is supposed that improved motion is attained by inducing a higher amplitude at a given frequency, and/or by attaining comparable amplitude under the application of a lower frequency.

Journal Article
TL;DR: In this article, the authors demonstrate the utility of field emission scanning electron microscopy (SEM) to generate images of sunscreen films in the presence and absence of several polymers.
Abstract: A mechanistic understanding of the role of polymers in waterproofing anhydrous sunscreen formulations has been hypothesized in the past, but has never been clearly established. In this article, we demonstrate the utility of field emission scanning electron microscopy (SEM) to generate images of sunscreen films in the presence and absence of several polymers. VA/butyl maleate/isobornyl acrylate copolymer was studied alone and in combination with hydroxypropyl cellulose and acrylates/dimethicone copolymer. Anhydrous sunscreen formulations were sprayed onto stratum corneum substrates and left to dry. SEM micrographs of treated stratum corneum sections were then collected at various magnifications. Vapor transmission data were collected using an evaporimeter to understand the permeability of these films in the presence and absence of film formers. Examination of the SEM images reveals that after spraying the product onto a layer of corneocytes, the sunscreen filters formed a hydrophobic barrier over the skin, whereas added polymers formed films over the sunscreen layer. The shape of the film formed by various polymers and its porosity were influenced by chemistry and concentration. When more than one polymer was incorporated in the sunscreen formulation, the interactions between the polymers influenced the formation of the film. Cumulative evaporimeter data indicated that the sunscreen phase had the highest reduction in cumulative evaporation rate (39.3%/h) followed by the addition of a film former to the spray, which reached an additional reduction of 17.9%/h in the best case. This method was also used to examine the film properties of a commercial sun protection factor 30 sunscreen product containing VA/butyl maleate/isobornyl acrylate copolymer. SEM micrographs of the commercial product applied to skin showed the same fingerprint as prototype formulations containing VA/butyl maleate/isobornyl acrylate copolymer. Overall, this method can be used by sun care scientists in the development and optimization of anhydrous sunscreen sprays.