Showing papers in "Journal of Cosmetic Science in 2010"

A survey of phthalate esters in consumer cosmetic products.

Abstract: Certain phthalate esters have been shown to cause reproductive toxicity in animal models. For this reason, the FDA has been monitoring the use of phthalate esters in cosmetics. In this study, the U.S. Food and Drug Administration (FDA) conducted a limited survey of 84 adult-use and baby-care cosmetic products for the presence of five phthalate esters: dimethyl phthalate (DMP), diethyl phthalate (DEP), benzylbutyl phthalate (BBP), dibutyl phthalate (DBP), and diethylhexyl phthalate (DEHP) (Figure 1). The analytes were extracted from a cosmetic product/Celite mixture with hexane, and the extract was then analyzed using reversed-phase high-performance chromatography (HPLC) on an instrument equipped with an ultraviolet radiation (UV) detector set at 230 nm. The analytes were separated on a Partisil octadecylsilane (ODS)-3 column (250 mm × 4.6 mm I.D., 5μm). The mobile phase consisted of a mixture of 50% water, 34% acetonitrile, 13% 2-propanol, and 3% methanol that was changed linearly (35 minutes) to 15% water, 55% acetonitrile, 25% 2-propanol, and 5% methanol and held for an additional ten minutes. Spiked recoveries in antiperspirant and nail color ranged from 88% to 104%. Thirty-one of the 60 adult-use cosmetic products were found to contain at least one phthalate ester. Twenty products contained DEP and 11 nail products contained DBP. Concentrations of DBP ranged from 123 μg/g to 62,607 μg/g. Concentrations of DEP ranged from 80 μg/g to 36,006 μg/g. Five of the 24 baby-care products contained DEP at concentrations ranging from 10 μg/g to 274 μg/g.

Natural moisturizing factors (NMF) in the stratum corneum (SC). I. Effects of lipid extraction and soaking.

Abstract: Natural moisturizing factor (NMF) is essential for appropriate stratum corneum hydration, barrier homeostasis, desquamation, and plasticity. It is formed from filaggrin proteolysis to small, hygroscopic molecules including amino acids. We hypothesized that common lipid extraction and soaking in water would alter the level of NMF in the upper SC and its biophysical properties. A novel method of measuring and quantifying the amino acid components of NMF is presented. Adhesive tapes were used to collect samples of the stratum corneum (SC) and were extracted with 6mM perchloric acid for analysis by reverse-phase HPLC. HPLC results were standardized to the amount of protein removed by the tapes. An increase in NMF was found with increased SC depth. Also, the combination of extraction and soaking was found to increase NMF loss relative to control or to extraction or soaking alone. Our results indicate that common skin care practices significantly influence the water binding materials in the upper SC. The findings have implications for the evaluation and formulation of skin care products.

Natural moisturizing factors (NMF) in the stratum corneum (SC). II. Regeneration of NMF over time after soaking.

Abstract: The detrimental effects of prolonged water exposure on skin are well known. Information on the effects of short-term exposure, e.g., during bathing, showering, and hand washing, on NMF levels is limited. In an attempt to isolate the effects of soaking on the NMF, a time course for skin sample collection was devised in which adhesive tapes were applied 0.5 and four hours after soaking of the treated arm. Significant decreases in NMF levels, quantified by HPLC analysis of serial tape strips, were observed 0.5 hours after soaking, with a replacement of NMF occurring by the four-hour mark. This replacement corresponds to a parallel rebound in skin pH also observed at these times. Stratum corneum hydration values, measured instrumentally as the rate of moisture accumulation (MAT), however, were depressed 0.5 hours post-soaking and remained low four hours later. In addition, significant increases in skin pH were observed during the immediate post-soak period. These findings suggest that short-term exposure to water alone produces significant changes in the stratum corneum.

The cell membrane complex: three related but different cellular cohesion components of mammalian hair fibers.

Abstract: The structure, chemistry and physical properties of the cell membrane complex (CMC) of keratin fibers are reviewed, highlighting differences in the three types of CMC. Starting with Rogers' initial description of the CMC in animal hairs, several important developments have occurred that will be described, adding new details to this important structure in mammalian hair fibers. These developments show that essentially all of the covalently bound fatty acids of the beta layers are in the cuticle and exist as monolayers. The beta layers of the cortex are bilayers that are not covalently bonded but are attached by ionic and polar linkages on one side to the cortical cell membranes and on the other side to the delta layer. The delta layer between cortical cells consists of five sublayers; its proteins are clearly different from the delta layer that exists between cuticle cells. The cell membranes of cuticle cells are also markedly different from the cell membranes of cortical cells. Models with supporting evidence are presented for the three different types of cell membrane complex: cuticle-cuticle CMC, cuticle-cortex CMC, and cortex-cortex CMC.

Direct inhibition of elastase and matrixmetalloproteinases and stimulation of biosynthesis of fibrillar collagens, elastin, and fibrillins by xanthohumol.

Abstract: In skin aging there is deterioration of the extracellular matrix's collagen and elastin fibers, from its reduced biosynthesis and increased degradation by elastase and matrixmetalloproteinases (MMPs). Xanthohumol is a flavonoid isolated from the hop plant Humulus lupulus L., with anti-microbial, antioxidant, anti-inflammatory, and anti-carcinogenic properties. The goal of this research was to investigate xanthohumol as an anti-skinaging agent via its beneficial regulation of the extracellular matrix. To this purpose, we examined the direct effect of xanthohumol on the activities of elastase and MMPs (MMPs 1, 2, and 9) and its effect on the expression (protein and/or transcription levels) of collagens (types I, III, and V), elastin, and fibrillins (1 and 2) in dermal fibroblasts. Xanthohumol significantly inhibited elastase and MMP-9 activities from its lowest concentration, and MMP-1 and MMP-2 at its higher concentrations, which implies a greater protective effect on elastin. It dramatically increased the expression of types I, III, and V collagens, and elastin, fibrillin-1, and fibrillin-2 in dermal fibroblasts. The effects were similar to those of ascorbic acid. This is the first report identifying xanthohumol's potential to improve skin structure and firmness: it simultaneously inhibits the activities of elastase/MMPs and stimulates the biosynthesis of fibrillar collagens, elastin, and fibrillins.

Changes in Structure and Geometric Properties of Human Hair by Aging

Abstract: To clarify hair changes by aging, the effect of age on hair properties was investigated from macro- to microscopic view points. Sensory hair luster tests were performed on 230 Japanese females from 10 to 70 years of age, revealing that hair luster decreases with age. The age dependence of the hair diameter and the ellipticity of the hair cross section could not explain luster reduction by aging. It has been determined that an irregular increase in fiber curvature occurs with age and is a cause of luster reduction with aging. A detailed structural analysis by synchrotron radiation microbeam X-ray diffraction revealed that the inhomogeneity in the lateral distribution of the hair microstructure increased with age and relates to the irregular increase in curvature. Such an increase in curvature is one of the important factors that leads to a poor alignment of hairs and luster reduction, and is related to the appearance of aging hair.

New alternatives to cosmetics preservation

Abstract: In recent years, there is a considerable interest in the development of preservative-free or self-preserving cosmetics. The aim of our work was to develop new cosmetic formulations by replacing chemical preservatives with ingredients with antimicrobial properties that are not legislated as preservatives according to Annex VI of Commission Directive 76/768/EEC. This paper describes the preservative efficacy of the well-known antimicrobial extracts of Lonicera caprifoleum and Lonicera japonica in combination with glyceryl caprylate and/or levulinic acid, p-anisic acid, and ethanol. We prepared a series of acidic (pH = 5.5) aqueous and O/W formulations, i.e., tonic lotion, shampoo, shower gel, conditioning cream, anticellulite cream, cleansing milk and peeling cream, containing (0.2% w/w) Lonicera extracts, alone in the case of tonic lotion and in combination with (1% w/w) glyceryl caprylate in the other products, and we performed challenge tests according to the European Pharmacopoeia procedures and criteria. Formulations such as shampoo, shower gel, and conditioning cream fulfilled criterion A, while tonic lotion, anticellulite cream, cleansing milk, and peeling cream fulfilled criterion B, in regard to contamination from A. niger. Furthermore, we evaluated the efficacy of the antimicrobial systems in two states of use: the intact product and after three weeks of consumer use. The results showed that A. niger was also detected during use by consumers in the products that satisfied only criterion B in challenge tests. The addition of antimicrobial fragrance ingredients such (< or = 0.3% w/w) levulinic acid or (0.1% w/w) p-anisic acid and/or (5% w/w) ethanol afforded products that met criterion A in challenge tests and were also microbiologically safe during use. The small quantity (5% w/w) of ethanol gave an important assistance in order to boost the self-preserving system and to produce stable and safe products.

Study and description of hydrogels and organogels as vehicles for cosmetic active ingredients.

Abstract: Cellulite, a clinical syndrome mainly affecting women, involves specific changes in conjunctive dermic and subcutaneous tissue, leading to vascular and hypertrophic alterations in adipose tissues and the consequent alteration of tissue structure. This paper describes the design of hydrogels and pluronic-lecithin organogels elaborated as vehicles of Aloe vera (Aloe vera linne) and Hydrocotyle asiatica (Centella asiatica) for the treatment of cellulite. The objective of this work was to carry out a complete evaluation of the proposed formulae through the study of the organoleptic and rheological properties of the formulae. Our work revealed that, in appearance, hydrogels show better organoleptic characteristics than organogels. On the other hand, from a rheological point of view, both hydrogels and organogels display a plastic behavior. However, the main difference between the two is that the more complex internal structure of the organogel bestows it with more viscosity. Finally, in vitro tests with Franz-type diffusion cells revealed that the release of cosmetic active principle from the tested excipients was appropriate, both in terms of magnitude and velocity.

Copper and calcium uptake in colored hair.

Abstract: During hair coloring a number of disulfide bonds in cystine are oxidized (1) to create cysteic acid, forming binding sites for metal ions such as Ca(2+ )and Cu(2+ )from tap water (2). The increased uptake of these metals can have a detrimental impact on fiber properties-for example, reducing shine and causing a poor wet and dry feel (3). In addition, the increased uptake of copper can also contribute to further fiber damage during subsequent coloring due to its ability to take part in metal-induced radical chemistry (4). It is important to know where in the fibers these metals are located in order to either effectively remove these metals or control their chemistry. Nanoscale secondary ion mass spectrometry (NanoSIMS) has been used to locate the calcium and copper within hair that has been treated with a colorant and washed multiple times in tap water containing these ions. Untreated hair is used as a baseline standard material. Images with up to 50-nm spatial resolution of the preferential locations of calcium uptake were obtained, showing a high concentration of calcium in the cuticle region of colored hair, specifically in the sulfur-rich regions (A-layer and exocuticle).

Influence of purple sweet potato extracts on the UV absorption properties of a cosmetic cream.

Abstract: Anthocyanins were added to a cosmetic cream to provide additional protection against UV radiation. The influence of anthocyanins on UV absorption ability was carefully evaluated. Anthocyanins were successfully extracted from TNG73 purple sweet potato using acidic ethanol and acidic water. Acidic ethanol-extracted anthocyanins had better radical scavenging ability, higher total phenolic content, and stronger reducing ability than acidic water-extracted anthocyanins. The cosmetic cream with 0.61 mg of total anthocyanins (per 100 g cream) absorbed approximately 46% of the incident UV radiation. Although the anthocyanins absorbed both UV-A and UV-B radiation, they were particularly effective against UV-B rays. This study demonstrates that the addition of anthocyanin extracts of purple sweet potato to a cosmetic cream improves the cream's UV absorption ability.

Anti-wrinkle activity of Platycarya strobilacea extract and its application as a cosmeceutical ingredient.

Abstract: In order to investigate the potential of Platycarya strobilacea fruit extract as an active ingredient for cosmetics, we measured their free-radical scavenging activity, elastase inhibitory activity, the expression of MMP-1 (matrix metalloproteinase-1), and type I collagen synthesis in normal human fibroblast cells. To isolate the main component compounds from P. strobilacea fruit extract, we purified the extract through solvent fractionation, column chromatography, and recrystallization. The component compounds were identified as ellagic acid and 4-O-xyloside of ellagic acid (ellagic acid 4-O-xylopyranoside). P. strobilacea fruit extract and ellagic acid increased the expression of type I collagen mRNA in a dose-dependent manner (up to 37% and 41% at 20 microg/ml and 1.0 microg/ml, respectively), comparable to that of ascorbic acid (up to 39% at 500 muM). A clinical study of measurements using visual evaluation and image analysis showed a statistically significant difference (p < 0.05) between the effects of the test and placebo products. This result suggests that P. strobilacea fruit extract could be used as an active ingredient for antiaging cosmetics.

Fatigue testing of hair-a statistical approach to hair breakage.

Abstract: The objective of this work is to describe an alternative approach for assessing hair breakage. The methodology involves the repeated application of force, together with an evaluation of the number of cycles required before breakage-an approach often termed fatigue testing. The technique provides novel results, which appear to indicate more sizable differences between samples than arise from conventional constant-rate extension experiments. For example, results illustrate a substantially higher tendency for breakage in Afro hair as compared to Caucasian hair-a conclusion that appears in line with consumer experiences. Also, findings suggest a substantially larger contribution from the relative humidity of the environment to the propensity for breakage under these conditions.The fatigue approach also lends itself to a novel means of data analysis in which breakage is treated as a statistical variable rather than as a mechanical parameter. By performing Weibull analysis of the data, a characteristic lifetime and a shape parameter are obtained to characterize the data, while survival probability plots can be generated to predict the propensity for breakage under a specific set of conditions.

18-MEA and hair appearance.

Abstract: The effects of the removal of 18-MEA on the dynamic contact angle (advancing contact angle and receding contact angle) and friction force (friction force microscopy (FFM)) were examined in the present study. Chemically untreated hair tresses formed more finely ordered bundles, with the fibers aligned more parallel to each other, in the wet state, and lying flat and aligned parallel to each other in the dry state. Hair tresses in which 18-MEA had been removed by potassium t-butoxide treatment formed coarser tangled bundles and were aligned in a disorderly manner in the wet state, causing the hair to become entangled and disorderly in the dry state. This was because the 18-MEA-removed hair fibers adhered to each other and were not easy to realign in the wet state. The distorted part of the bundle dried faster and the tress shape was eventually fixed in the entangled shape. One role of 18-MEA is to allow hair fibers to lie flat and parallel with respect to each other in the wet state by providing relatively high receding contact angles and low surface friction. Hair alignment in the dry state is directly affected by hair alignment in the wet environment, particularly in the case of damaged hair.

Study of hair shine and hair surface smoothness.

Abstract: A new hair visual appearance measurement system called SAMBA from Bossa Nova Technologies (Venice, CA) has been employed to measure effects of cosmetic treatments on hair shine and surface smoothness of different types of hair samples. Experimental procedures for evaluations of shine value and surface cuticle angle of hair samples treated with rinse-off products (shampoo or/and conditioner) have been successfully established and applied. We demonstrated that hair spray and conditioner formulas containing PPG-3 benzyl ether myristate (PBEM) (1) showed great performance on shine enhancement for hairs with light and medium colors. Instrumental measurement of shine values was also conducted to compare different commercial shampoo and conditioner products. This study showed reliable utility of SAMBA system and demonstrated the shine enhancement of PBEM in hair care.

Brazilian oils and butters: the effect of different fatty acid chain composition on human hair physiochemical properties.

Abstract: This study evaluated the performance of five oils and three butters extracted from Brazilian plants with different fatty chain composition on hair mechanical properties, split end formation, combing analysis and gloss measurements. Oil treatment reduced the combing force percentage for wet conditions. However, the hair treated with butters showed poor combing. Except for ucuuba butter, oils and butters used in this work had generally no influence on hair tensile properties. In general, hair treated with oils showed a significant gloss increase and a decrease for split end formation. The fatty acid composition of the oils and butters tested showed an effect on the physicochemical properties of hair.

Moisturizing and anti-sebum secretion effects of cosmetic application on human facial skin.

Abstract: For human skin, high water content and low sebum secretion are considered to be main features of fair skin. To explore the proper personal care regimen for facial skin, we investigated the change of skin physiologic parameters after cosmetic application by measuring the skin water content, transepidermal water loss, and skin sebum secretion on facial skin before and after the cosmetic application using the Corneometer, Tewameter, and Sebumeter, respectively. The results indicated that the cosmetics application kept a higher water content and a lower transepidermal water loss, and at the same time, a lower sebum secretion 4 h and 8 h after the cosmetic application, compared with those before it. The situation was maintained in the succeeding three-week continuous use of the cosmetics. It could be concluded that the cosmetic application on human facial skin might provide some moisturizing effect and at the same time an anti-sebum effect, which favors the maintenance of good skin physiological function after applying skin care products. Our results might provide a scientific personal care regimen for human facial skin to prompt the balance for the hydrolipid film on skin.

Protection of oxidative hair color fading from shampoo washing by hydrophobically modified cationic polymers.

Abstract: The fading of oxidative color in hair as a result of daily shampoo washing activities has become a common problem and a source of frequent complaints by consumers. The fading occurs primarily through hair dye solubility in water. One aspect of the current study investigates the physical and chemical factors that influence hair color fading during the washing process. This is accomplished by testing hair dye dissolution in water from dyed hair samples with variation of surfactant type, pH, and hair type. Furthermore, a new approach to preventing color fading is developed aiming to provide an effective barrier function for hair dye from dissolving into water. The preliminary investigation of a series of polymers with various functional groups indicates that polymers with hydrophobically modified and cationic functionalities are most effective in preventing hair dye dissolution in water. It is also evident that a synergistic effect of the polymer's hydrophobic moieties and cationic charges are important on hair color protection during shampoo washing processes. A primary example of a polymer within this category is a cationic terpolymer of vinylpyrrolidone, dimethylaminopropyl methacrylamide, and methacryloylaminopropyl lauryldimonium chloride (INCI: Polyquaternium-55). The color protection benefit of this polymer is evaluated using newly developed methodologies for evaluating hair color changes, such as hair color fading tests through multiple shampoo washes with mannequin heads and hair tresses, both derived from human hair, colorimetry, and quantitative digital image analysis. In addition, new infrared spectroscopic imaging techniques are used to detect the hair dye deposition behavior inside hair fibers both with and without the color protection treatment. Both visual and instrumental measurement results indicate that Polyquaternium-55 provides a high level of color protection when formulated in a hair color protection regimen with up to 50% color protection. This regimen significantly outperforms commercial products that were tested containing a color protection claim. The proposed mechanism for the anti-fading action of hydrophobically modified polymers includes a cationic charge-reinforced hydrophobic barrier. This model is supported by evaluating the color fastness effect of several different polymer chemistries and by measuring hair surface hydrophobicity changes.

A statistical analysis of hair breakage. II. Repeated grooming experiments.

Abstract: The objective of this work was to introduce the idea of analyzing data from repeated brushing and combing experiments on hair in accordance with standard fatigue testing approaches. In mechanical testing terms, the brushing and combing of hair represents a fatiguing process wherein individual strands experience repeated exposure to an external stimulus. Therefore, in accordance with fatiguing principles, one expects a gradual propagation of flaws within individual fibers until, ultimately, catastrophic failure (breakage) results. A previous paper in this series described the modeling of single-fiber fatigue data using the Weibull approach, and, in so doing, introduced the idea of treating fiber breakage as a statistical variable. Here, a grouped Weibull methodology was used to analyze breakage data from repeated brushing and combing experiments. At a top level, the generation of the two Weibull parameters provides a means of characterizing these experiments. However, the real strength of the approach involves the ability to generate survival probability plots that provide predictions as to the likelihood of fiber breakage under different conditions. Therefore, assuming laboratory experiments are a reasonable representation of real-life conditions, it becomes possible to predict breakage rates on actual heads as a function of different habits and practices. It is also shown how the two Weibull parameters, together with information about the number of fibers in the test tresses, allow for the modeling of repeated brushing and combing tests and allow anyone to re-create the experimental outcome for comparison to their own experiences. These principles have been demonstrated using experiments that compare breakage in virgin and chemically damaged hair, while also showing how conditioning treatments provide considerable retardation.

Comparison of hydration, tyrosinase resistance, and antioxidant activation in three kinds of pearl powders.

Abstract: In recent years, people have bred freshwater pearls as a substitute for natural pearls that occur in seawater, and they have also developed water-soluble pearl powder (P-w) and ultra-micro (P-mu) and ultra-nano pearl powder (P-n) products. However, neither the scientific value of pearl powder, nor the differences in efficiencies of different pearl powder products is still unknown. In this study, the effectiveness of three kinds of pearl powder products in various applications was compared. Tests for transepidermal water loss (TEWL) and evaluations of the skin surface hydration of test subjects showed that pearl powder has a satisfactory moisturizing effect on skin and that P-mu has a distinctly stronger moisturizing effect than P-w. The three pearl powder products can also significantly reduce the activation of tyrosinase and free radicals. In tests for reducing power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) for scavenging free radicals, P-n and P-mu showed better performance than P-w. These results provide a reliable scientific basis for the use of pearl powder in beauty treatment, resistance to aging, and clinical medical treatment.

Evaluation of the effect of Thai breadfruit's heartwood extract on the biological functions of fibroblasts from wrinkles.

Abstract: In previous studies, extract from Artocarpus incisus's heartwood (breadfruit tree) had antioxidant and antimelanogenic activities. Here, we investigated the extract's action on facial skin fibroblasts from wrinkled skin and nonwrinkled skin biopsies, particularly in the production of type I procollagen and metalloproteinase- 1 (MMP-1) and in the reorganization of collagen fibers. We found that the extract at a concentration of 50 microg/ml significantly enhanced percent viability and proliferation of wrinkled-skin fibroblasts. Flow cytometry showed that a 3.6-fold increased proportion of the wrinkled-skin fibroblasts were in their cell cycle S-phase, indicating increased proliferation. Type I procollagen synthesis by wrinkled-skin fibroblasts was augmented by the extract. Nonwrinkled-skin fibroblasts had higher synthesis and were unaffected by the extract. MMP-1 secretion was greater for wrinkled-skin fibroblasts, but the extract decreased its secretion for both fi broblasts samples. Fibroblasts were incorporated in collagen lattice disks. Lattices with nonwrinkled-skin fibroblasts contracted uniformly by 56% after a three-day culture and the extract had little effect. However, wrinkled-skin fi broblast lattices failed to show appreciable contractions (to 12% after three days). But remarkably, the extract conferred an ability of the wrinkled-skin fibroblast lattices to fully contract (to 53%). This shows that wrinkled-skin fi broblasts have the ability to reorganize collagen but that the extract can reactivate this latent potential. Our findings for the first time reveal that A. incisus's heartwood extract reversed the fibroblast deficiencies in the metabolism and reorganization of collagen and may underlie a wrinkle treatment.

Determination of retinol, retinyl palmitate, and retinoic acid in consumer cosmetic products.

Abstract: Retinol and retinyl palmitate are frequently used in cosmetic products. A simple, rapid, and sensitive reversed-phase high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection was developed for the quantitation of retinol, retinyl palmitate, and retinoic acid in cosmetic preparations. The analytes were extracted from a cosmetic/Celite mixture using a solvent system composed of equal amounts of hexane, isopropanol, and ethyl acetate, and the extract was injected directly into an HPLC chromatograph with a C18 column and UV detector set at 330 nm. Chromatographic separation was achieved by gradient elution with a mobile phase, starting with aqueous ammonium acetate buffer/methanol that was gradually changed to methanol/dichloromethane. The average recoveries of retinol, retinyl palmitate, and retinoic acid from spiked cosmetic products were 95% or higher. In a survey of twenty-nine consumer cosmetic skin care products labeled to contain retinoids, most products were found to contain either retinol or retinyl palmitate at concentrations up to 2.2% (w/w), while a few products contained both ingredients. A number of products also contained cis isomers of retinol that could be quantitatively distinguished from the all-trans compound. The method can be used to quantitate several retinoids and their isomers in cosmetic products. The method will be useful for obtaining information needed to estimate levels of exposure to retinoids from cosmetic products.

The thickness of 18-MEA on an ultra-high-sulfur protein surface by molecular modeling.

Abstract: The use of computational chemistry techniques via molecular modeling software provides additional support to the hair surface model by Negri et al. (1) and refines the thickness of the 18-methyl eicosanoic acid (18-MEA) lipid layer attached by thioester linkages to an ultra-high-sulfur protein (UHSP) at 1.08 ± 0.2 nm. This value compares favorably to the thickness of that same layer from X-ray photoelectron spectroscopy (XPS) measurements by Ward et al. (2) at 1.00 ± 0.5 nm on Soxhlet-extracted wool. The model clarifies that the results of Ward et al. via XPS are not an artifact of high vacuum (3), but due to relaxation of the 18-MEA structure onto the wool protein backbone as suggested by Zahn et al. (4). In this molecular model, 18-MEA is attached to beta sheets of an UHSP via thioester linkages as suggested by Negri et al. in their 1993 study (15) and by earlier work by Evans et al. (5). The beta sheets of this model provide an intersheet spacing of 0.7 nm and a beta sheet density of 1.42 g/cm(3) compared with Allworden membrane fractions that varied from 1.39 to 1.54 g/cm(3) (6).

Analysis of vitamin E in commercial cosmetic preparations by HPLC.

Abstract: A specifi c HPLC method, with an RP–C-18 column and a UV detector, for simultaneous determination of vitamin E (tochopherol, T)/T acetate (TA) in four commercial and two experimental cosmetic products is described. Three solvent systems for extraction of T/TA were assessed: isopropyl alcohol; 10:90 v/v hexane-methanol mixture (method 1); and methanol alone (method 2). The procedure was accurate, as indicated by high recovery (97.8–101.8% and 100.1–102.5% for T and TA, respectively) and precise (RSD was only 0.9–3.26% and 0.73–3.35% for T and TA, respectively). The limits of detection for T and TA were 200 and 300 ng/ml, respectively, while the limits of quantitation were 250 and 400 ng/ml, respectively. The range of reliable quantifi cation was 5–50 μg/ml. Isopropanol as solvent resulted in a turbid extract. Method 1 and method 2 of extraction showed high recovery (98.5–99.9% and 97.2–97.9% for T and TA, respectively). After a few weeks of analysis, method 1 resulted in retention time drift, peak broadening, non-reproducible results, and progressive loss of HPLC-column integrity. Methanol alone (method 2) was equally as effi cient as that of the mixture of methanol with 10% hexane (method 1) for extraction. The described analytical procedure proved to be accurate, precise, and suitable for simultaneous determination of T and TA in real commercial cosmetic products.

Hair breakage--how to measure and counteract.

Abstract: A system to determine the efficacy of hair treatments in terms of anti-breakage and split end prevention was developed which involves the repeated combing of hair strands. The device allows ten hair strands to be combed simultaneously. First, the influences of chemical hair treatments like bleaching on hair breakage were examined. In a next step, the protective effects of benchmark products from the market were studied. Since nearly all commercial products with anti-breakage claims contain silicones combined with cationic polymers, alternative actives were searched. In a test series with different waxes in shampoo formulations with a variable number of parameters, the particle size was found to be the factor with the strongest influence on the amount of wax deposited on the shampooed hair. Therefore, a targeted development was started, resulting in a combination of several ethers dispersed in sodium laureth sulfate. Excellent conditioning, anti-breakage and split ends protection properties of the compound were found, showing also a dosage dependency. The latter could be explained by analyzing the amounts of waxes applied on treated hair. In these experiments, a dependency on the concentration in the shampoo was found.

Evaluation of novel synthetic conditioning polymers for shampoos

Abstract: Cationic polymers have traditionally been used in shampoo formulations to impart conditioning properties to hair. In this study, commercial synthetic cationic polymers were investigated using coacervate formation, objective wet comb analysis, silicone deposition and panel studies to determine structure function properties with the goal of developing novel conditioning polymers. New polymers were synthesized and, based on criteria determined in the first part of the study, found to have marginal improvement over existing synthetic cationic conditioning polymers. A novel experimental polymer developed for a different industry was also investigated for conditioning properties. This polymer showed significant enhancement of silicone deposition over current commercial polymers, including cationic guar, even at significantly reduced silicone and polymer concentrations. The experimental polymer exhibited parity or improvement over benchmark polymers in panel studies, and similar performance to other synthetic polymers in objective wet comb studies.

High-performance liquid chromatography with dual-wavelength ultraviolet detection for measurement of hinokitiol in personal care products

Abstract: Hinokitiol is found in the heartwood of several cupressaceous plants and is frequently added to cosmetic products such as hair restorers, skin lotions, and body soaps because of its potent and broad-spectrum antibacterial activity. In this study, we established a simple method of hinokitiol determination by high-performance liquid chromatography (HPLC) with dual-wavelength ultraviolet detection at 240 and 345 nm, using a reversed-phase C4 column (RP-4). The retention time of hinokitiol was 7.1 min at both wavelengths. The value of the symmetry coefficient of the hinokitiol peak was close to 1 when the RP-4 column, not an RP-8 or RP-18 column, was used. With the RP-4 column, the regression equation for hinokitiol showed good linearity in the range of 0.05-5 microg/ml, with a detection limit (signal-to-noise ratio of 3) of 0.005 microg/ml at 240 nm and 0.01 microg/ml at 345 nm. The coefficients of variation at 240 and 345 nm were less than 8.2% and 8.7%, respectively, and the recovery was good. The proposed method was used for the determination of hinokitiol in commercial hair restorers, skin lotions, and body soaps.

Reduction-induced surface modification of human hair.

Abstract: A microfluorometric method has been developed to characterize lipid removal or "delipidation" of the human hair cuticula during light exposure and chemical grooming processes such as oxidation (bleaching) and reduction. In the case of photochemical and chemical oxidation, lipid removal ("delipidation" of the F-layer or lipid-layer) from the outer beta-layer of the exposed scale faces and generation of cysteic acid groups occurs. This "delipidation," which ultimately results in "acidification" of the scale faces, leading to a change in surface chemistry from hydrophobic to hydrophilic, can be detected and quantified by microfluorometry by tagging, e.g., with the cationic fluorochrome Rhodamine B. In the case of reduction, similar tagging of the acid sites on the scale faces is possible, but this time, Rhodamine B reacts with the mixed disulfide containing a carboxyl group that will be ionized above a pH of about 4. In addition to this, we have shown by microfluorometric scanning that the negative charges generated in the cuticle surface can be used to bind low-molecular-weight quaternary conditioners. This process can be considered as "relipidation" or "refatting" of the scale faces. We have shown in earlier studies (1) that this entire process of oxidation-induced "delipidation" and subsequent "relipidation" of the acidic scale faces with a cationic conditioning molecule can also be reliably quantified by X-ray photoelectron spectroscopy (XPS). Furthermore, single-fiber wettability scanning using the Wilhelmy technique, which is highly sensitive to any changes in surface chemistry, is well-suited to detect and characterize treatment-induced changes in the chemical nature of the hair surface from hydrophobic to hydrophilic.

A new oxidant for hair coloring.

Abstract: Coloring hair using a level 3 permanent colorant involves two processes, lightening the underlying melanin and information of the colored chromophores inside the hair. In a typical in-market products the oxidant used to achieve these changes is hydrogen peroxide buffered at pH 10 with an alkalizer such as ammonium hydroxide. A new oxidant has been developed based on the combination of ammonium carbonate, hydrogen peroxide and glycine at pH 9 that can match the lightening and color performance of the current oxidant. It has the advantage that both the carbonate and hydrogen peroxide concentrations can be changed to alter the lightening performance making it a more flexible oxidant. This allows the capability to lighten the hair in a shorter time, or with lower hydrogen peroxide levels. This paper discusses the key oxidizing species that are present in both systems and the mechanisms of melanin lightening. In addition, the lightening performance will be assessed as a function of time, pH, hydrogen peroxide concentration and carbonate concentration. The importance of glycine to the oxidant is also described along with a proposal for its mechanism of action. It has been demonstrated that the addition of glycine can control the undesired formation of carbonate radicals that can be generated from the oxidant. The control of these radicals enables the oxidant to deliver excellent lightening with no negatives in fiber damage bs. conventional oxidants.

Simplified assay of diethylene glycol and ethylene glycol in various raw materials by capillary gas chromatography.

Abstract: The FDA has recently taken steps to reduce risks due to raw materials affected by economically motivated adulteration (EMA). One area of great interest is diethylene glycol (DEG) or ethylene glycol (EG) adulteration of glycerin, propylene glycol, and solutions of sorbitol, for which the USP monographs have recently been revised (1). Such adulterations have occurred many times and in many countries, including a tragic episode between November 2008 and January 2009 in which 84 children in Nigeria died after ingesting teething syrup contaminated with DEG (9,10). To eliminate this problem, the FDA has required manufacturers of finished products to assay and confirm that incoming glycerin, propylene glycol, and sorbitol solutions meet the USP limits, and the FDA/USP has incorporated such testing into the identity requirements of its updated monographs.Unfortunately, even though USP test procedures detail a simultaneous DEG and EG assay for these materials, different standard solutions are specified depending upon whether the incoming sample is glycerin, propylene glycol, or a sorbitol solution; in addition, a certain gas chromatography (GC) capillary phase is detailed for sorbitol solutions, while the assays for glycerin and propylene glycol use a different capillary phase, requiring column changeovers, separate GC systems, or front/rear column configuration. In addition, NF monographs for polyethylene glycols (PEG) and polyethylene glycol monomethyl ethers (MPEG) used in pharmaceutical products also require DEG and EG testing (detailing their own specific tests); three separate test procedures for these types of raw materials (the larger PEG-type polymers are assayed differently than their smaller counterparts), making assay at QC unwieldy.This paper describes a single, simple test procedure that is applicable to the simultaneous assay of DEG and EG in all types of the described raw materials, using one standard solution. The assay procedure involves straightforward isolation, trimethylsilylation, and simultaneous capillary gas chromatographic quantitation using capillary GC with flame ionization detection. Although the USP-NF limits are 0.10% DEG and 0.10% EG (and 0.25% total DEG plus EG for the PEG and MPEG products), in reality any EMA would be at levels significantly higher than that, as low-level illegal EMA would not be economically advantageous. The scope of this project was not to fully validate this technique for inclusion in USP-NF, but just to demonstrate its applicability for those wishing to utilize it or take it further.

Influence of functionalized silicones on hair fiber-fiber interactions and on the relationship with the macroscopic behavior of hair assembly.

Abstract: J. Cosmet. Sci., 60, 261–271 (March/April 2009) Synopsis It is well established that silicones alter hair surface properties and that silicones have a significant impact on the macroscopic behavior of hair assembly, such as visual appearance, combing performance and manageability of the hair. In order to fine-tune the chemistry of functionalized silicones for specific consumer benefits and hair types, we investigated the influence of silicones on hair fiber–fiber interactions and their correlation to hair volume. The incline plane fiber loop method, implemented with a high-precision motorized rotary stage, was used to quantify the fiber–fiber interactions. Low load static friction was studied as a function of polymer molecular weight, dose and chemical architecture. This information was related to the macroscopic behavior of hair assembly, using virgin curly hair in high humidity.