Journal of cosmetic science最新文献

Mixed surfactant and surfactant-polymer compositions have been reported to decrease surfactant deposition onto and penetration into the skin relative to single surfactant compositions, potentially improving the mildness of the product. Previous workers in this area [see Moore et al., J. Cosmet. Sci.54:29-46 (2003), and subsequent publications] employed a procedure in which excised porcine skin was exposed to a surfactant solution containing radiolabeled sodium dodecyl sulfate (¹⁴C-SDS) for 5 h. We have developed an improved SDS penetration assay using excised human skin that reflects typical consumer exposure times for rinse-off products. Using the new protocol, we were able to see a significant decrease in ¹⁴C-SDS penetration from a sodium lauryl sulfate (SLS)/polyethylene oxide composition applied to excised skin for either 2 or 10 min, as compared to SLS only. Furthermore, differences between the SDS penetration patterns on porcine skin and human skin were seen with a second SLS/polymer system; consequently, we do not recommend porcine skin for routine mildness screening by ¹⁴C-SDS penetration.

The aim of these two clinical studies was to evaluate the sensory characteristics and irritation potential of a prototype disinfectant spray (containing 0.13% w/v benzalkonium chloride and a cooling agent) in subjects with experimental wounds. The pilot study was a single center, "replicated latinClinicalTrials.ClinicalTrials. square design," randomized and double-blinded study. The pivotal study was a single center, randomized, controlled, crossover, double-blinded study, following a direct comparison test design of the study products. The experimental wounds were generated using sequential tape strippings of the forearm skin before product application. The test product was compared with the currently marketed BACTROBAN® disinfectant spray, negative control (0.9% w/v saline), and positive control (70% w/v isopropyl alcohol, pilot study only). The pilot study was intended to inform the study design and sample size for the pivotal study. The pilot study demonstrated that the positive control product delivered significantly more irritancy (stinging /burning sensory) than the negative control product on the experimental wound, which verified the integrity of the wound model. The results of the pivotal study suggested that the prototype formulation delivered significantly more cooling sensation than both BACTROBAN® disinfectant spray and negative control at 3 and 5 min after product application, and overall for a 15-min period after application. No statistically significant differences in product liking were observed between the prototype disinfectant spray and the BACTROBAN® disinfectant spray or negative control. The prototype disinfectant spray, BACTROBAN® disinfectant spray, and control products were well-tolerated in these studies.

Cosmetics, such as lipstick, can affect an individual's perception of attractiveness and morale. Consumer concern with the safety of synthetic colorants has made the need for alternative natural color sources increasingly urgent. Our goal was to evaluate the feasibility of anthocyanin (ACN) extracts as colorants in lipstick formulations. Lipstick formulations were colored with ACN-rich materials. Accelerated environmental testing typical of the cosmetic industry were used: incubation at 20°, 37°, and 45°C for 12 weeks and temperature abuse cycles between 20°/37°C or -20°/20°C. Color (CIELab) and total monomeric ACN (pH-differential) changes were monitored to determine shelf stability of the product. All formulations exhibited acceptable color for lipsticks. Shelf stability was determined to exceed 2 year based on the accelerated testing conditions. Formulations containing cyanidin as their main ACN were the most stable (elderberry, purple corn, and purple sweet potato). ACNs could be used as suitable alternatives to synthetic colorants in lipid-based topical formulations.

Using skin autofluorescence (SAF) as a marker of advanced glycation end-products (AGEs) has been extensively studied in the last decade since the introduction of the noninvasive in vivo measurement technique. Data have shown the level of skin AGEs increases with chronological age in healthy human beings, and this increase is substantially higher in age-matched diabetic patients. In skin research, glycation with the accompanying accumulation of skin AGEs has been regarded as one of the primary skin aging mechanisms that contribute to skin wrinkling and the loss of skin elasticity. To date, the totality of SAF data reported in literature has been obtained from measurements on the arm, and noninvasive measurement of facial skin AGE accumulation would add great value to skin aging research. In this study, we report the levels of facial and forearm skin AGEs in 239 men and women of 21-65 year of age. Significantly lower levels of AGEs were detected in the facial skin than in the forearm skin from the young Caucasian groups, and the difference was much larger for men than for women. The rate of change in skin AGE level over age was found to be about 50% higher in men than in women, which further highlights the gender difference. A statistically significant correlation between the levels of skin AGE and facial wrinkling was also observed. The facial skin AGE data may provide new insight into skin aging research.

Cosmetic emulsions containing plant extracts should be tested in a range of temperatures from 5°C to 40°C to be sure that they will be stable during general use by consumers and that plant extracts used as antioxidants do not accelerate oxidative degradation of their oil base. The oxidative stability of argan oil-in-water emulsions containing 1% and 5% commercial acerola, willow, and rose extracts [or 0.01% butylhydroxytoluene (BHT)], stored at 5°C and 20°C for 6 months and at 40°C for 4 weeks, was monitored by the determination of peroxide content. The antioxidant or pro-oxidant activities of extracts or BHT in emulsions were expressed as the protection factor (PF) and inhibition of peroxide formation (Ip). At the end of storage, 5% willow, 0.01% BHT, 1% willow, and 5% acerola were the most protective for emulsions stored at 5°C. At 20°C, the most effective was 0.01% BHT, 5% rose, and 5% acerola. At 40°C, inhibition of peroxide formation calculated for 1% rose, 5% acerola, and 0.01 % BHT was similar. Altogether, the results show that some plant extracts, depending on storage conditions, may act as pro-oxidants, whereas the others can be applied as natural antioxidants instead of synthetic BHT.

Torsional analysis of single human hairs is especially suited to determine the properties of the cuticle and its changes through cosmetic processing. The two primary parameters, which are obtained by free torsional oscillation using the torsional pendulum method, are storage (G') and loss modulus (G″). Based on previous work on G', the current investigation focuses on G″. The results show an increase of G″ with a drop of G' and vice versa, as is expected for a viscoelastic material well below its glass transition. The overall power of G″ to discriminate between samples is quite low. This is attributed to the systematic decrease of the parameter values with increasing fiber diameter, with a pronounced correlation between G″ and G'. Analyzing this effect on the basis of a core/shell model for the cortex/cuticle structure of hair by nonlinear regression leads to estimates for the loss moduli of cortex (G″_co) and cuticle (G″_cu). Although the values for G″_co turn out to be physically not plausible, due to limitations of the applied model, those for G″_cu are considered as generally realistic against relevant literature values. Significant differences between the loss moduli of the cuticle for the different samples provide insight into changes of the torsional energy loss due to the cosmetic processes and products, contributing toward a consistent view of torsional energy storage and loss, namely, in the cuticle of hair.

A petroleum-free skin cream was developed using food-grade ingredients. The rheological and sensorial properties of this petroleum-free skin cream were compared to a commercially available petroleum-based skin cream. Specifically, large-amplitude oscillatory shear (LAOS) characterization of the two skin creams was performed. The petroleum-free skin cream showed similar linear and nonlinear viscoelastic rheological properties, comparable skin hydration functions, and consumer acceptance as the commercially available skin cream. A schematic diagram aiming to correlate the physical and sensorial properties of skin cream was also proposed at the end of the work. Results of this work could provide the cosmetic industry necessary information for the development of alternatives for petroleum-based skin creams.

Skin produces sebum through sebocytes. Hyper-seborrhea creates conditions for the development of inflamed cutaneous alterations through bacteria colonization triggering dead cell accumulation and pro-inflammatory mediator release. Study of sebum production, its modulation, and its consequences requires complementary in vitro models in order to evaluate the effect of molecules on cell metabolisms. Clinical studies need to be performed to confirm in vitro results. Effects of phenylpropanoids, obtained by elicitation and purification from plant cell culture of Syringa vulgaris (CCSV), were studied on sebocytes, keratinocytes, and explants, all derived from normal human skins. Normal human sebocytes (NHSs) expressed markers such as cytokeratin-7, cytokeratin-4, and perilipin-2 (PLIN-2) (1); the latter being colocalized with lipid droplets. Lipid droplets clearly appeared and their size increased rapidly when lipogenic agents were used. NHS, normal human keratinocytes (NHK), and explants reacted to presence of bacterial fragments which trigger pre-inflammatory mediator release. CCSV reduced lipid storage and release of pre-inflammatory mediators in NHS, NHK and explants. CCSV also reduced P. acnes growth and triggered beta-defensin-2 and cathelicidin synthesis by NHS, two natural antimicrobial peptides. On volunteers, sebum production, inflamed blemishes, and retentional lesions were significantly reduced after 1 month treatment with CCSV.

Benzalkonium chloride (BAC), which is a mixture of C₈ and C₁₈ alkylbenzyldimethylammonium chlorides, has an important biocide character and is used in many cosmetics, especially wet wipes, as a preservative and/or antibacterial agent. The concentration range of BAC is 0.005–0.5 % and it is an irritant substance when used at high concentrations. Thus, the concentration of BAC should be carefully monitored in commercial products intended for skin use. In this study, a capillary electrophoresis (CE) analysis method for BAC quantification was developed. The quantitative analysis was carried out by the external standard method. The electrophoretic separation was performed by using 75 mM (pH 6.0) phosphate buffer solution containing 30% acetonitrile as the electrolyte. The separation voltage was 10 kV and the temperature was held at 18°C. Samples were introduced into the capillary column hydrodynamically using 50.0-mbar pressure over a 3-s period. The developed method was validated and applied on samples prepared by wringing out antibacterial wet wipes containing BAC without any further extraction. The linearity of the method was controlled by applying the Mandel test. The limit of detection (LOD) values for the developed method were 0.313 and 0.309 µg/ml and the limit of quantification (LOQ) values were 1.042 and 1.029 µg/ml for C₁₀ and C₁₂ derivatives, respectively.