Showing papers in "Journal of Cosmetic Science in 2012"

Physiological effect of a probiotic on skin.

Abstract: Synopsis Introduction and objective: Normal human skin can produce a range of antimicrobial chemicals that play an important part in eliminating potential cutaneous pathogens. Lactobacillus plantarum is a gram-positive bac- teria that produces antimicrobial peptides, which when applied to the skin can act like an anti-infl ammatory as well as enhance the antimicrobial properties of the skin. Clinical studies were conducted to determine the effect of lactobacillus extract on improvement of skin barrier and reduction of erythema from chemical irri- tant, skin microfl ora, and acne. Results show that lactobacillus extract was effective in reducing skin ery- thema, repairing skin barrier, and reducing skin microfl ora, thereby exhibiting an effective reduction in acne lesion size and erythema at 5%, but not at 1%.Conclusion: Based on the results of these studies, lactobacillus extract (5%) can be used to treat mild acne lesions.

Fairness via formulations: a review of cosmetic skin-lightening ingredients.

Abstract: Skin-lightening cosmetics are in big demand across Asia, and the quest for fairness has led to identifi cation of many new ingredients. The mechanisms underlying pigmentation have been researched extensively and the knowledge is being updated regularly. This review serves to list the ingredients that are commercially available for that purpose and the modes of action through which the lightening is effected. Skin-lightening ingredients are also classifi ed based on their sources; it is signifi cant that far more botanicals have made the list than have synthesized compounds. Tyrosinase inhibition as a means of skin lightening is still the most reported method, followed by other methods such as Mitf inhibition, down regulation of MC1R activity, interference with melanosomal transfer, and melanocyte loss.

Determination of total lead in 400 lipsticks on the U.S. market using a validated microwave-assisted digestion, inductively coupled plasma-mass spectrometric method.

Abstract: In 2009, the U.S. Food and Drug Administration (FDA) published lead (Pb) content results from a small survey of 20 tube lipsticks with red shades using a validated inductively coupled plasma-mass spectrometric (ICP-MS) method developed by FDA chemists. The study was prompted by a media report suggesting that potential exposure to lead from lipsticks under conditions of ordinary use might be harmful. The FDA has since investigated the lead content of tube lipsticks by conducting an expanded survey that included a variety of shades and manufacturers, at varying prices. The purposes of the expanded survey were to ascertain the levels of lead in lipsticks sold on the U.S. market, to identify any categories of lipstick with elevated levels of lead, and to compare the results to those from the initial small survey. Four hundred lipsticks available on the U.S. market in the spring of 2010 were tested for total lead content using the FDA's validated method. The analyses were performed by a private laboratory contracted by the FDA. The maximum lead level found was 7.19 mg Pb/kg. Thirteen of the 400 lipsticks were found to contain levels greater than 3.06 mg Pb/kg, the highest amount found in the initial survey. The average lead concentration found in the expanded survey was 1.11 mg Pb/kg, which was very close to the average of 1.07 mg Pb/kg found in the initial survey. Some statistically significant associations between lead level and parent company were found. The contract requirements, testing procedures, and findings from the expanded survey are described here.

Inhibition of sebum production and Propionibacterium acnes lipase activity by fullerenol, a novel polyhydroxylated fullerene: Potential as a therapeutic reagent for acne

Abstract: Oxidative stress plays a major role in acne formation; this suggests that oxygen-radical scavengers could be potential therapeutic agents. Fullerenol C60(OH)44, a recently developed polyhydroxylated fullerene, is a spherical carbon molecule that has many hydroxyl groups capable of potent radical-scavenging activity. We have investigated its inhibitory effects in vitro on sebum production in hamster sebocytes and in Propionibacterium acnes lipase activity. Sebum production was significantly reduced by 1.5 microM of fullerenol in cells that had been irradiated with 10 mJ/cm2 UVB, although it was not altered in the non-irradiated cells, indicating that fullerene is a sebum suppressor for sebocytes under oxidative stress, such as that induced by UVB. It was also found that fullerenol has inhibitory activity against P. acnes lipase. These results suggest that fullerenol could be a beneficial skin care reagent for controlling acne vulgaris by suppressing sebum in the inflammatory response and by reducing P. acnes lipase activity.

Development of photochemoprotective herbs containing cosmetic formulations for improving skin properties.

Abstract: Botanical photochemoprotectives are used because they act on various stages to prevent skin cancer and photoaging. The aim of this study was to prepare herbal creams from various photochemoprotective herbs and to perform efficacy studies on them by using physicochemical, microbiological, safety, psychometric, biophysical, and sun protection factor measurements. Herbal creams were prepared by incorporating hydroalcoholic extracts of Curcuma caesia (rhizome), Areca catechu (seeds), Centella asiatica (leaves) Cinnamon zeylanicum (dried bark), and Tamarindus indica (fruit pulp) in varied concentrations (1-5% w/w) in a base cream. The efficacy of all formulations was checked out for four weeks on 60 normal subjects on the volar forearm for evaluation of biophysical properties, and for psychometric evaluations (fragrance, lathery feel, softness, irritation, stickiness, smoothness, and aftereffect on the skin) and safety measurements. In the biophysical characterization, a cutometer for viscoelasticity, a mexameter for melanin content, a corneometer for hydration, and a sebumeter for sebum determination were used. All the cream formulations with 1% and 3% w/w extracts showed positive results and passed physicochemical, microbiological, and safety tests. The SPF values increased as the concentration of extract was increased up to a limit in the formulations. The SPF values were significantly higher (p < 0.01) in formulations with 3% herbal extract than with 1% herbal extract. Increased skin hydration, sebum levels, viscoelasticity, and decreased melanin values were obtained. The Cinnamon, Centella, and Tamarindus formulations were found more effective as photoprotectives than the Areca and Curcuma formulations.

Aloe-emodin inhibits proliferation of adult human keratinocytes in vitro.

Abstract: Aloe-emodin (AE) is a plant-derived hydroxyanthraquinone with several biological activities. It is present in a variety of skin-conditioning agents containing aloe extracts, but its influence on keratinocyte growth was not examined so far. We investigated the influence of AE on human keratinocyte proliferation and apoptosis in vitro. AE significantly inhibited proliferation of cultivated human keratinocytes at 5 μM concentration, as revealed by incorporation of radioactive thymidine. The antiproliferative effect of AE was accompanied with induction of apoptosis, but not necrosis, as demonstrated by flow cytometric analysis and lactate dehydrogenase release assay. Based on the half maximal inhibitory concentration values, we demonstrated that AE may impair proliferation of keratinocytes at concentrations far below the industry standards for commercial products containing aloe extracts. Therefore, further research of AE effects on the human skin and proper labeling of products are necessary for maximizing benefits from aloe extracts and to avoid undesired responses.

Inhibitory effects of geranic acid derivatives on melanin biosynthesis.

Abstract: The effects of geranic acid and its structurally related derivatives (geraniol, citronellic acid, and citronellol) on cell viability and melanin biosynthesis in Melan-a cells were evaluated in this study. Among them, geranic acid evidenced the strongest inhibitory activity on melanin production, coupled with low cell toxicity. Treatment with 500 μM of this compound resulted in a reduction in melanin content of 35.4% as compared to the live cell percentage (91.7%). Moreover, geranic acid also inhibited tyrosinase activity and intracellular tyrosinase expression in a dose-dependent manner. These results show that geranic acid may function as a skin depigmenting agent via the inhibition of tyrosinase activity and expression within melanocytes.

Crude ethanol extracts from grape seeds and peels exhibit anti-tyrosinase activity

Abstract: This study aimed to evaluate the anti-tyrosinase activities of ethanol extracts from the peels and the seeds of Kyoho grapes and Red Globe grapes (KG-PEE, KG-SEE, RGG-PEE, and RGG-SEE). The total phenolic content in KG-SEE and RGG-SEE was 400 +/- 11 and 339 +/- 7 mg gallic acid equivalent/g, respectively, about 22 times and 13 times that in KG-PEE and RGG-PEE, respectively. Both seed extracts showed significantly higher anti-tyrosinase activity than the peel extracts due to their high total phenolic content. The gallic acid content in RGG-SEE was twice that in KG-SEE, and gallic acid showed high anti-tyrosinase activity; thus, RGG-SEE had higher anti-tyrosinase activity than KG-SEE. Lineweaver-Burk plots revealed that the inhibitory mechanism of the ethanol extracts from the grapes was a mix-type inhibition. Grape seed has a greater total phenolic content and has potential as a skin-lighting agent.

Effects of oxidative treatments on human hair keratin films.

Abstract: The effects of hydrogen peroxide and commercial bleach on hair and human hair keratin films were examined by protein solubility, scanning electron microscopy (SEM), immunofluorescence microscopy, immunoblotting, and Fourier-transform infrared spectroscopy. Protein solubility in solutions containing urea decreased when the keratin films were treated with hydrogen peroxide or bleach. Oxidative treatments promoted the urea-dependent morphological change by turning films from opaque to transparent in appearance. Immunofluorescence microscopy and immunoblotting showed that the oxidation of amino acids and proteins occurred due to the oxidative treatments, and such occurrence was more evident in the bleach-treated films than in the hydrogen peroxide-treated films. Compared with hair samples, the formation of cysteic acid was more clearly observed in the keratin films after the oxidative treatments.

Natural oils and waxes: studies on stick bases.

Abstract: The objective of the present article was to examine the role of origin and quantity of selected natural oils and waxes in the determination of the thermal properties and hardness of stick bases. The natural oils and waxes selected for the study were sunflower, castor, jojoba, and coconut oils. The selected waxes were yellow beeswax, candelilla wax, and carnauba wax. The hardness of the formulations is a critical parameter from the aspect of their application. Hardness was characterized by the measurement of compression strength along with the softening point, the drop point, and differential scanning calorimetry (DSC). It can be concluded that coconut oil, jojoba oil, and carnauba wax have the greatest influence on the thermal parameters of stick bases.

A new chemical approach to optimize the in vitro SPF method on the HD6 PMMA plate.

Abstract: In a previous study, we demonstrated that control of the roughness of molded PMMA plates improves in vitro SPF reproducibility However, in vitro/vivo deviations are still observed Sunscreens show different behavior during spreading on the HD6 surface according to the formulation, resulting in a more or less homogenous distribution The hydrophilic nature of HD6 appears to contribute significantly during spreading Two different sunscreens offering a homogenous and non-homogenous distribution were investigated to check if the interfacial tension between product and substrate has a real influence on the spreading quality Using microscopic observations, we attempted to correlate the in vitro SPF results with the product's spreading property In order to reduce this interfacial tension, an HD6 pretreatment with an amphoteric surfactant, cocamidopropyl betain, was performed In vitro SPF on "pretreated HD6" was examined using a cohort of 30 products This pretreatment led to reliable results, demonstrating good association with the in vivo SPF

Determination of kojic acid in a skin-whitening cosmetic by high-performance liquid chromatography coupled with ultraviolet detection after pre-column derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole.

Abstract: Various methods for the determination of kojic acid (KA), a skin-whitening agent, have been reported by high-performance liquid chromatography (HPLC). In this study, the concentration of KA in a skin-whitening cosmetic was analyzed by HPLC with ultraviolet detection (380 nm) after pre-column derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) in order to improve the sensitivity. The HPLC column was 150 mm x 3.0 mm i.d., containing 5 microm particles of C18 packing material. The mobile phase was prepared by the addition of acetonitrile (550 ml) to 450 ml of Milli-Q water containing trifluoroacetic acid (0.1 v/v%). The samples were eluted from the column at room temperature at a flow rate of 0.35 ml/min. The retention time of NBD-KA was 7.8 min. A standard curve was obtained after derivatization with NBD-F in borate buffer (pH 9.0) at 40 degrees C for 7 min. The calibration plot was linear, in the range of 0.25-5 microg/ml with an r2 value of 0.9982, and the lower limit of detection was 0.06 microg/ml (at a signal-to-noise ratio of 3:1; absolute amount of 0.4 ng/20 microl injection). The coefficient of variation was less than 9.6%. It was found that the amount of KA in a skin-whitening cosmetic was 237 +/- 14 microg/ml (range: 219-255 microg/ml). Recovery in addition-recovery tests was within the range of 83.4% to 98.1%.

Panthenyl triacetate transformation, stimulation of metabolic pathways, and wound-healing properties in the human skin.

Abstract: Vitamin B5 and its derivatives are well known in personal care applications and are often used in wound healing and soothing compositions. However, little is known about the biochemical pathways involved. A better knowledge of these pathways would help to understand some of the mechanisms of action and suggest further applications. We have investigated the transformation of D-panthenyl triacetate (PTA) into D-panthenol (PAN) and its skin diffusion on human volunteers by Raman spectroscopy. Additionally, we have utilized human skin biopsies and quantitative RT-PCR to demonstrate the effect of PTA compared to PAN on 27 metabolic markers when introduced at 2% in a cosmetic emulsion. Then we conducted a double-blind clinical study to measure the effect of PTA compared to PAN on wound healing, measured by transepidermal water loss (TEWL), when incorporated at 3% in a cosmetic emulsion. Results show de-acetylation of PTA into PAN and an increased activity of PTA compared to PNA over time in the skin. Metabolic marker analysis demonstrates stimulation of energetic pathways such as glycolysis and the citric acid cycle, but also of synthesis pathways such as isoprenoids and lipid synthesis, by PTA and PAN. Finally, the clinical study demonstrates a statistically significant effect by PTA on wound healing after 72 hours when compared to a saline treatment. Statistical significance was not achieved by PAN or a placebo treatment. Due to the differences between PTA and PAN action, different applications in personal care products can be suggested. Moreover, PTA seems more effective than PAN for a long-lasting wound healing action.

Skin-whitening effects of Mediterranean herbal extracts by in vitro and in vivo models.

Abstract: Several plant extracts are able to protect skin against ultraviolet-light-induced damage and hyperpigmentation in a safe way. The anti-melanogenic effect of herbal extracts seems to be related to their antioxidant activity and their polyphenolic content. In this study, the skin-whitening effect of some Mediterranean species, already known for their strong antioxidant and radical scavenger activity, has been evaluated by in vitro and in vivo models. The results obtained showed that herbal extracts possessed an inhibitory effect on tyrosinase enzyme. Each extract showed a similar inhibiting activity even though it was less intensive than kojic acid and hydroquinone. Otherwise, a significant higher activity than kojic acid and hydroquinone was observed when the herbal extracts were combined. Furthermore, the anti-melanogenic activity and an evaluation of skin tolerance were affected by in vivo methods.

Protection against UVB-induced oxidative stress in human skin cells and skin models by methionine sulfoxide reductase A

Abstract: Environmental trauma to human skin can lead to oxidative damage of proteins and affect their activity and structure. When methionine becomes oxidized to its sulfoxide form, methionine sulfoxide reductase A (MSRA) reduces it back to methionine. We report here the increase in MSRA in normal human epidermal keratinocytes (NHEK) after ultraviolet B (UVB) radiation, as well as the reduction in hydrogen peroxide levels in NHEK pre-treated with MSRA after exposure. Further, when NHEK were pre-treated with a non-cytotoxic pentapeptide containing methionine sulfoxide (metSO), MSRA expression increased by 18.2%. Additionally, when the media of skin models were supplemented with the metSO pentapeptide and then exposed to UVB, a 31.1% reduction in sunburn cells was evident. We conclude that the presence of MSRA or an externally applied peptide reduces oxidative damage in NHEK and skin models and that MSRA contributes to the protection of proteins against UVB-induced damage in skin.

Relationships among skin conditions, mood, and polyunsaturated fatty acids of RBCs in healthy women.

Abstract: Little is known about nonpathological facial skin problems at present. The aim of the present study was to investigate the relationships among facial skin conditions, mood, and the fatty acid composition of red blood cells (RBCs) in women. One hundred and thirty-two apparently healthy Japanese women aged between 20 and 60 years were recruited. Facial skin conditions were analyzed using a Robo Skin Analyzer, and the RBC fatty acid composition was also determined. Questionnaires concerning mood were administered. Forehead pigmentation was more mood-dependent (in 20s group) and less arachidonic acid (AA)-dependent (in all participants) than that in other areas of the face. Actually there was no correlation in pigmentation between the forehead and other areas of the face when adjusted for age, smoking, and drinking. Skin conditions were adversely correlated with a negative mood. α-Linolenic acid concentrations were negatively correlated with negative mood scores. Pigmentation characteristics in the forehead were independent from other areas of the face. Negative mood and AA were adversely correlated with skin conditions.

Simultaneous analysis and monitoring of 16 UV filters in cosmetics by high-performance liquid chromatography.

Abstract: Sixteen UV filters were simultaneously analyzed using the high-performance liquid chromatographic method. They were drometrizole (USAN Drometrizole), 4-methylbenzylidene camphor (USAN Enzacamene), menthyl anthranilate (USAN Menthyl anthranilate), benzophenone-3 (USAN Oxybenzone), benzophenone-8 (USAN Dioxybenzone), butyl methoxydibenzoylmethane (USAN Avobenzone), ethylhexyl triazone (USAN Octyl triazone), octocrylene (USAN Octocrylene), ethylhexyl dimethyl p-aminobenzoic acid (USAN Padimate O), ethylhexyl methoxycinnamate (USAN Octinoxate), p-aminobenzoic acid (USAN Aminobenzoic acid), 2-phenylbenzimidazole-5-sulfonic acid (USAN Ensulizole), isoamyl p-methoxycinnamate (USAN Amiloxate), and recent UV filters such as diethylhexyl butamidotriazone (USAN Iscotrizinol), methylene bis-benzotriazolyl tetramethylbutylphenol (USAN Bisoctrizole), and terephthalylidene dicamphor sulfonic acid (USAN Ecamsule). Separation of the UV filters was carried out in a C(18) column with a gradient of methanol-phosphate buffer, and the UV detection was at 300, 320, or 360 nm without any interference. The limits of detection were between 0.08 and 1.94 μg/ml, and the limits of quantitation were between 0.24 and 5.89 μg/ml. The extracting solvent for the UV filters was methanol, except for ethylhexyl triazone and methylene bis-benzotriazolyl tetramethylbutylphenol, which were prepared with tetrahydrofuran. The recoveries from spiked samples were between 94.90% and 116.54%, depending on the matrixes used. The developed method was applied to 23 sunscreens obtained from local markets, and the results were acceptable to their own criteria and to maximum authorized concentrations. Consequently, these results would provide a simple extracting method and a simultaneous determination for various UV filters, which can improve the quality control process as well as the environmental monitoring of sunscreens.

Characterization and release kinetics of nicotinamide microemulsion-based gels.

Abstract: The aim of this study was to investigate physicochemical characteristics and to determine in vitro release kinetics of prepared nicotinamide microemulsion-based gels (MBGs). Nicotinamide microemulsions (ME) were composed of 3% w/w nicotinamide, 7% w/w water, 25% w/w soybean oil, and 65% w/w of 9:1 oleth-10:isopropyl alcohol mixture. A water-in-oil (w/o) type ME was converted to three MBGs. ME was combined with 5% w/w of colloidal silica to obtain MBG-1, with 5% w/w of 0.5% w/w carbomer solution to obtain MBG-2, or with a mixture of 3% w/w of 0.5% w/w carbomer solution and 2% w/w of PEG-40 hydrogenated castor oil to obtain MBG-3. The results indicated that MBG-1 was a clear gel with plastic flow while MBG-2 and MBG-3 were turbid gels with Newtonian flow. MBG-1 was physically and chemically stable at 4°C as well as at ambient temperature (approximately 30°C) during the 2-month study period. The color darkened when stored at 60°C. The release kinetics of MBG-1 was best fitted to zero order model. The in vitro release of nicotinamide from MBG-1 through cellulose membrane was compared with that from the ME and an oil-in-water (o/w) commercial cream (CC). The rank order of release rate of nicotinamide from different formulations was MBG-1 > ME > CC.

Melanosome transfer evaluation by quantitative measurement of Pmel 17 in human normal melanocyte-keratinocyte co-cultures: effect of an Alaria esculenta extract.

Abstract: Numerous strategies have been proposed to evaluate melanosome transfer. Methods allowing quantitative measurements of this transfer in human normal cellular models, however, are very few and often require extremely specialized devices that are expensive and difficult to use. As a part of the melanosome-specific membrane-bound glycoprotein, Pmel 17 is released from the melanosome membrane by ectodomain shedding. We reasoned, therefore, that it should be possible to evaluate melanosome transfer by quantifying this "soluble" Pmel 17. The Pmel 17 ELISA assay developed permits a detection of 10 to 1000 ng/ml of this glycoprotein in human normal melanocyte-keratinocyte co-culture media. As expected, niacinamide, a well-known melanosome transfer inhibitor, significantly reduced the Pmel 17 quantities found in the culture media. This validated our experimental design. We then used our model to show that a whitening cosmetic active compound, i.e., an Alaria esculenta extract, can (at least in part) enable a significant decrease in the melanosome transfer to produce a lightening effect without affecting melanin production. This research provides a simple and efficient method to quantify melanosome transfer in a human normal co-culture model. It is a particularly useful tool with which to facilitate the development of new active whitening compounds.

Trehalose in hair care: heat styling benefits at high humidity.

Abstract: Human hair switches that have been treated with trehalose solution and straightened using hot irons show longevity of the straight style even in high-humidity conditions. This anti-humidity benefit is especially noticeable if the straight style has been created at low relative humidity. It is proposed that hot-iron straightening of trehalose-treated switches produces in situ glassy forms of the sugar that act as water sinks at high humidity to provide anti-humidity benefits. Adsorption isotherms and powder x-ray studies of different forms of trehalose and moisture uptake of hair treated with the sugar suggest that the ability of a glassy form of trehalose to regulate moisture in the fiber and consequently affect its viscoelastic properties is a major factor in providing long-lasting straight style in humid conditions.

Intermolecular disulfide cross-linked structural change induced by permanent wave treatment of human hair with thioglycolic acid.

Abstract: Permanent wave treatment for hair has been used for many decades. However, certain aspects of the treatment involved are still not well understood. Reduction of disulfide (SS) bonds and their subsequent oxidation are essential for inhibiting fiber degradation. We attempted to elucidate scission and reformation mechanisms of SS cross-links by treating them with a reducing agent, thioglycolic acid (TGA), and an oxidizing agent, sodium bromate. In order to estimate the change in the cross-link density of hair before and after treatment, a rubber elasticity theory was applied to the force-extension curve for rubber-like swollen hair fibers treated in a specific diluent mixture. A two-phase structural model was assumed that corresponds to the globular matrix of keratin-associated proteins (KAP) dispersed in a swollen network of intermediate filament (IF) proteins. Important structural parameters were obtained by fitting the force-extension curve to the theoretically derived relationship between elastic forces originating from the non-uniform network and extension ratios. The three parameters extracted are the number of intermolecular SS bonds in IF, the volume fraction of matrix protein in the fiber, and the shape of the matrix domain. It was found that TGA attack on the SS bonds between globular matrix proteins occurs preferentially as compared with those between IF proteins and induces the shape change of the matrix domain from an ellipsoidal to a near-spherical form.

A patent survey case: How could technological forecasting help cosmetic chemists with product innovation?

Abstract: Patents represent a free and open source of data for studying innovation and forecasting technological trends. Thus, we suggest that new discussions about the role of patent information are needed. To illustrate the relevance of this issue, we performed a survey of patents involving skin care products, which were granted by the United States Patent and Trademark Office (USPTO) between 2006 and 2010, to identify opportunities for innovation and technological trends. We quantified the use of technologies in 333 patents. We plotted a life cycle of technologies related to natural ingredients. We also determined the cross impact of the technologies identified. We observed technologies related to processes applied to cosmetics (2.2%), functional packaging and applicators (2.9%), excipients and active compounds (21.5%), and cosmetic preparations (73.5%). Further, 21.6% of the patents were related to the use of natural ingredients. Several opportunities for innovation were discussed throughout this paper, for example, the use of peptides as active compounds or intracellular carriers (only 3.9% of the technologies in cosmetic preparations). We also observed technological cross impacts that suggested a trend toward multifunctional cosmetics, among others. Patent surveys may help researchers with product innovation because they allow us to identify available and unexplored technologies and turn them into whole new concepts.

Microscopic evaluation of polymeric film properties of anhydrous sunscreen compositions and their relation to absorption and water resistance.

Abstract: The aim of this study was to investigate the mechanism by which a VA/butyl maleate/isobornyl acrylate copolymer increases the SPF and water resistance of sunscreen formulations. Anhydrous sunscreen formulations with and without polymer were applied on polymethyl methacrylate (PMMA) plates and absorbance spectra were generated. Before immersion, the areas under the curve for the control and test samples were 98.49 and 117.09, respectively, and were 94.63 and 118.22, after immersion. Static and after-immersion, in vivo SPF values confirmed a boost in SPF and an increase in water resistance for the formulation containing the polymer (VA/butyl maleate/isobornyl acrylate copolymer). Digital imaging of sunscreen films combined with image analysis and contact angle measurements suggest that the polymer conformation changes upon exposure to water. The polymer forms a protective barrier over the sunscreen film upon exposure to water, which explains the enhancement in water resistance. The polymeric film formed has a different refractive index than the sunscreen film. The change in refractive indices causes diffraction of incident light, thus increasing its pathlength, leading to an increase in SPF.

Advantages of a high-throughput measure of hair fiber torsional properties.

Abstract: While the tensile response of fibers of human hair is the most extensively studied mode of mechanical deformation, the properties of hair in different deformation modes remain of interest and can provide valuable insight into the effects of chemical treatments. Previously reported methods for the measurement of fibers in torsional deformation have inherent systematic errors, are low-throughput, and are operator-intensive. This paper presents a new method for the measurement of fiber torsional properties developed to reduce these errors and to improve the efficiency of the technique. This method was designed to be fully automated, requiring no operator input during an experiment, and affording higher sample throughput while improving the ease of use in variable climatic conditions. The new method is compared to a conventional torsional pendulum method for measuring fiber shear modulus, and an evaluation of experimental reproducibility is made using hair and nylon fibers. It was found that the new method provides absolute values for shear modulus similar to those of the pendulum technique, with reduced run-to-run variability between fibers, while enabling larger sample numbers to be explored in shorter times.

Simultaneous determination of 13 components in oxidative hair dyes by high-performance chromatography using an ion-pair reagent.

Abstract: A reliable high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of 13 dye intermediates, including benzenediamines, aminophenols, benzenediols, naphthalenediol, and diaminopyridine, in oxidative hair dyes. Samples were extracted with 50% ethanol by adding sodium dithionite to prevent oxidation. The influences of buffer type, buffer pH, ion-pair reagent, and elution gradient were studied. A C18 column with aqueous compatibility and acetonitrile-citric acid mobile phase system (pH 2.6) with sodium 1-octanesulfonate as ion-pair reagent were selected for the separation of target compounds. Detection was performed by a diode array detector, (DAD) and two different wavelengths (280 and 331 nm) were used for quantification. Results showed that 13 dye intermediates got good separation within 25 min. The detection limits of these compounds were in the range of 0.2-2 mg/l. The calibration curves were linear within 2-500 mg/l with 0.999 as a typical correlation coefficient. The recoveries of target compounds in hair dyes ranged from 81.7% to 102.0% with four addition levels. The method described was validated by five different laboratories and successfully applied to the analysis of commercial oxidative hair dyes.

Preparation of emulsions by rotor-stator homogenizer and ultrasonic cavitation for the cosmeceutical industry.

Abstract: Oil-in-water (O/W) nanoemulsions play an important key role in transporting bioactive compounds into a range of cosmeceutical products to the skin Small droplet sizes have an inherent stability against creaming, sedimentation, flocculation, and coalescence O/W emulsions varying in manufacturing process were prepared The preparation and characterization of O/W nanoemulsions with average diameters of as low as 6299 nm from palm oil esters were carried out This was achieved using rotor-stator homogenizer and ultrasonic cavitation Ultrasonic cell was utilized for the emulsification of palm oil esters and water in the presence of mixed surfactants, Tween 80 and Span 80 emulsions with a mean droplet size of 6299 nm and zeta potential value at -378 mV Results were comparable with emulsions prepared with rotor-stator homogenizer operated at 6000 rpm for 5 min The stability of the emulsions was evaluated through rheology measurement properties This included non-Newtonian viscosity, elastic modulus G', and loss modulus G″ A highly stable emulsion was prepared using ultrasonic cavitation comprising a very small particle size with higher zeta potential value and G' > G″ demonstrating gel-like behavior

UVc-irradiation sublethal stress does not alter antibiotic susceptibility of staphylococci (MRSA, MSSA, and coagulase-negative staphylococci) to β-lactam, macrolide, and fluoroquinolone antibiotic agents.

Abstract: Skin tanning, either by exposure to natural sunlight or through use of UV sunbeds, has become a popular practice in the US, where it is estimated that approximately 1 million times per day someone in the US uses UV radiation for skin tanning, equating to 30 million Americans (circa 10% of the US population) who use a tanning bed. As well as exposing the host to periods of UV radiation, such practices also expose commensal skin bacteria, including Staphylococcus aureus, to such UV radiation. Previous work has indicated that environmental stresses on bacteria may lead to an upregulation of stress responses, in an attempt for the organism to combat the applied stress and remain viable. UV light may act as an environmental stress on bacteria, and so it was the aim of this study to examine the effect of UVc light on the antibiotic susceptibility of commensal skin bacteria, to determine if UV radiation would increase the antibiotic resistance of such skin flora and thus lead to a potential skin flora with increased antibiotic resistance. Previously, it has been shown that UVc light has a greater mutational effect on bacteria compared to lower-energy UV forms, including UVa and UVb light. Therefore, we decided to employ UVc light in our study to amplify the potential for mutational events occurring in skin staphylococci organisms (n=8) including methicillin-sensitive Staphylococcus aureus (n=2), methicillin-resistant Staphylococcus aureus (n=4), and coagulase-negative staphylococci (Staphylococcus haemolyticus) (n=2) were exposed to varying degrees of sublethal radiation via UVc light, and their minimum inhibitory concentration (MIC) susceptibility was determined by broth dilution assay against three classes of commonly used antibiotics, namely β-lactams (penicillin), macrolides (erythromycin), and fluoroquinolones (ciprofloxacin). There was no significant difference between antibiotic susceptibility before UVc exposure and until maximum sublethal stress, prior to cell death due to fatal UVc exposure with the cells. These results indicate that UV environmental stress/exposure does not upregulate antibiotic resistance, and therefore these data indicate that UVc radiation does not lead to a more antibiotic-resistant population in the staphylococci organisms post-exposure.

Differential wetting characterization of hair fibers.

Abstract: Surface wetting is one of the key properties of human hair used to indicate the extent of chemical/mechanical damage and the outcome of conditioning treatment. Characterization of hair wetting property is a challenging task due to the non-homogeneous nature of hair fi bers and the requirement for sensitive equipment. Motivated by these considerations, we developed a new methodology, termed a differential wetting characterization (DWC), which would allow rapid and reliable characterization of the wetting property of hair fi bers. This method is based on observation of a number of droplets suspended on a pair of parallel fi bers stretched in a horizontal plane. The wetting behavior of the fi bers can be deduced from the shape assumed by the droplets. When the wetting properties of the two hair fi bers are identical, the droplets suspended between the fi bers assume a symmetric confi guration. In contrast, on the fi bers with dissimilar wetting characteristics, the droplets will assume a skewed confi guration towards a more hydrophilic fi ber. This makes it possible to differentiate the hydrophobicities of the tested fi bers. In this paper it is demonstrated that the proposed DWC method is capable of differentiating the changes in wetting property of hair surfaces in response to either chemical or physical treatment. Results of the paper indicate that the DWC method is applicable for broad wetting differentiation of various fi bers.

Sand resistance of sunscreens.

Abstract: Like water resistance in sunscreens, sand resistance in sunscreens is the ability of the sunscreen to retain its effectiveness while undergoing sand treatment. The influence of the type of sand on the sand resistance of sunscreens has not been described. The sand resistance of a control standard sunscreen, P2, and data on three grades of Quickrete commercial grade sand, #1961, #1962, and #1152, are described. These sands represent a fine sand, a medium sand, and an all-purpose sand. Using the methodology described in the 2007 proposed amendment of the Final Monograph (1) with one exception, we obtained an SPF of 16.5 (1.6) for the control standard, compared to the expected SPF of 16.3 (3.4). After a five-minute treatment of sand #1961, #1962, or #1151, the SPF of the control standard was 18.3 (1.6), 18.4 (2.0), and 17.5 (2.2), respectively. Thus, all three sands exhibited a similar sand-resistance response. Thus, there was no significant difference in the average SPF with and without sand. The medium grade sand, Quickrete commercial grade #1962, was preferred for sand-resistance testing because the fine sand was difficult to remove from the subject's backs and the coarse sand was unpleasant to the subjects.