Journal of cosmetic science最新文献

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.

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.

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.

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.

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.

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.

It has been experimentally shown that hair subjected to permanent wave treatment quickly changes into uncurled hair during daily hair-care activities. However, the mechanism of curl fallout has not been clarified. In previous studies, the relationship between permanent wave treatment and disulfide bonds in hair has been studied. Because permed hair falls out its waves without any chemical treatment, we focused on the hair microstructure rather than the disulfide bonds. To examine the relationship between the hair curl shape and the intermediate filament (IF) organization in hairs, scanning microbeam small-angle X-ray scattering measurements were performed. It was found that in permed hairs, the IF orientation on the convex side of the curvature was different from that on the concave side. By contrast, for permed hairs with curl fallout, the IF orientation on the convex curvature side was not significantly different from that on the concave side. Our findings suggest that the curl shape of permed hairs is related to its anisotropic IF orientation between the convex and concave side of the curl, and control of this IF orientation will allow for effective reduction of curl fallout.

The present study reports the effects of adding L-glutamic acid to a new enrichment broth designated as R-TATP broth, to promote the growth of slow-growing mold microorganisms such as Aspergillus brasiliensis and Aspergillus oryzae, without interfering in the growth of other types of microorganisms. This L-glutamic acid containing enrichment broth would be particularly valuable in a rapid microbial detection assay such as an adenosine triphosphate (ATP) bioluminescence assay. By using this new enrichment broth, the amount of ATP (represented as relative light unit ratio after normalized with the negative test control) from mold growth was significantly increased by reducing the time of detection of microbial contamination in a raw ingredient or personal care product formulation from an incubation period of 48-18 h. By using L-glutamic acid in this enrichment broth, the lag phase of the mold growth cycle was shortened. In response to various concentrations of L-glutamic acid in R-TATP broth, there was an increased amount of ATP that had been produced by mold metabolism in an ATP bioluminescence assay. By using L-glutamic acid in R-TATP broth in an ATP bioluminescence assay, the presence of mold could be detected in 18 h as well as other types of microorganisms that may or may not be present in a test sample. By detecting the presence or absence of microbial contamination in 18 h, it is superior in comparison to a 48-96 h incubation period by using either a standard or rapid detection method.

Hydrophilic polymers are widely used in the cosmetics industry as thickening agents/rheology modifiers. These thickening agents have different chemical structures which affect the rheological properties, as well as the sensory attributes of the formula. Systematic study is important to determine the relationship among them. Six commonly used hydrophilic polymers, including cellulose derivatives and synthetic polymers, were used as thickening agents in a series of oil-in-water emulsions. The rheological properties were evaluated in relation to the thickening mechanism and polymer structures. Comprehensive skin sensory studies were carried out to test factors such as the pick-up, rub-in, and after-feel of these emulsions and the control sample. Results showed that all the samples demonstrated a non-Newtonian and shear-thinning behavior, and synthetic polymer-based formulas were more viscous than cellulose derivative-based ones. All eight attributes for the factors of appearance, pick-up, and rub-in showed statistically significant differences (p ≤ 0.05), whereas all five attributes for the after-feel factor exhibited no statistically significant differences (p > 0.05) for different thickening agents. According to the results calculated using Pearson's correlation coefficients, four sensory attributes were mostly correlated with the rheological parameters.

Data were generated from three studies to assess the tolerability and acceptability of a prototype cosmetic lip balm. Dermatological assessments of topical compatibility (primary and cumulative irritability and sensitization), photoirritant and topical photosensitizer potential, and acceptability for safe use of a prototype cosmetic lip balm on sensitive skin are summarized. In Study 1, the product was applied to the volunteers' backs under a semiocclusive patch followed by patch removal/reapplication over 6 weeks to assess the irritant and allergic potential of the product. Dermatological assessments were performed at the beginning and end of the study or when there was evidence of positivity or adverse event. Study 2 was conducted by applying the product to the volunteers' backs under a semiocclusive patch, followed by patch removal/reapplication and irradiation of the test area with ultraviolet A (UVA) radiation at various intervals over 5 weeks. Dermatological assessments were performed to assess the product's role in the induction of photoirritancy and photosensitization. Clinical and subjective assessments for acceptability were obtained during Study 3 in volunteers with a diagnosis of sensitive skin and those who used the product as per instructions for use during the study period. The data generated from the three studies demonstrated no evidence of primary or cumulative dermal irritation or of dermal sensitization. In addition, no photoirritation potential or photosensitization potential was observed. As assessed by dermatologic monitoring and subject diary entries, the prototype lip balm did not cause irritation or sensitization reactions when used for 28 days in volunteers with a diagnosis of sensitive skin. Based on these findings, the prototype lip balm can be considered suitable for use for people with sensitive skin.