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Showing papers in "Journal of Cosmetic Science in 2004"



Journal ArticleDOI
TL;DR: In the measurement of in vitro skin permeation, the L-ascorbic acid stabilized in this study showed considerableskin permeation ability, indicating its potential applicability in pharmaceutics and cosmetics.
Abstract: This study presents a new approach that can stabilize effectively L-ascorbic acid in water-in-oil-in-water (w/o/w) double emulsions. Basically, the behavior of L-ascorbic acid in the aqueous phase was observed, considering its molecular deformation. Then, it was found that the stability determined in the aqueous phase by high-performance liquid chromatography (HPLC) showed that the collapse of ionization of L-ascorbic acid played a crucial role in protecting the molecular deformation. Then, the stable aqueous system was incorporated into the internal aqueous phase of the double emulsions. From the HPLC analysis, it was observed that the L-ascorbic acid in an appropriate system showed high molecular stability for a long time. Moreover, in the measurement of in vitro skin permeation, the L-ascorbic acid stabilized in this study showed considerable skin permeation ability, indicating its potential applicability in pharmaceutics and cosmetics.

98 citations


Journal ArticleDOI
TL;DR: The basic properties and the in vitro release rate kinetics of azelaic acid (AA), alternatively vehiculated in different phospholipid-based vesicles such as ethosomes or liposomes, were investigated and the release rate was more rapid from ethosomal systems than from liposomal systems.
Abstract: The basic properties and the in vitro release rate kinetics of azelaic acid (AA), alternatively vehiculated in different phospholipid-based vesicles such as ethosomes or liposomes, were investigated. Ethosomes were produced by a simple method based on addition of an aqueous phase to an ethanol solution (comprised between 20\% and 45%, v/v) of soy phosphatidyl choline (5%, w/w) and AA (0.2%, w/w) under mechanical stirring. Liposomes were obtained by the same composition in the absence of ethanol with the reverse-phase evaporation method. Vesicle size was measured by photon correlation spectroscopy (PCS), evidencing smaller mean diameters and narrower dimensional distributions in the case of ethosomes with respect to liposomes. In order to obtain homogeneously sized vesicles, both ethosomal and liposomal dispersions were extruded through polycarbonate membranes with pores of calibrated diameter (400 nm and 200 nm). Vesicle morphology was characterized by freeze-fracture scanning electron microscopy (SEM) showing the presence of unilamellar vesicles both in liposome- and in ethosome-based dispersions. Free energy measurements of the vesicle bilayers were conducted by differential scanning calorimetry (DSC). AA diffusion from ethosomal or liposomal dispersions and from ethosomes and liposomes incorporated in a viscous gel was investigated by a Franz cell assembled with synthetic membranes. The release rate was more rapid from ethosomal systems than from liposomal systems. In particular, ethosomes produced by the highest ethanol concentration released AA more rapidly, and the same trend was found using viscous forms.

67 citations


Journal ArticleDOI
TL;DR: Caucasian females showed marked age-related wrinkle formation in the lower areas of the face, probably due to sagged in the subzygomatic area, which suggests a higher susceptibility to sagging in theSubzyGomatic area of Caucasian females.
Abstract: We compared age-related changes in wrinkles in eight areas of facial skin (forehead, glabella, upper eyelid, corner of the eye, lower eyelid, nasolabial groove, cheek, and corner of the mouth) and sagging in the subzygomatic area of Caucasian females and of Japanese females. The subjects studied included 85 healthy Caucasian females (ages 20-69 years) living in Cincinnati in the U.S. and 70 Japanese females (ages 20-69 years) living in Tokyo. Photos of the face in frontal and in oblique 45 degrees views were analyzed. Wrinkles in the face and sagging in the subzygomatic area were graded on Japanese photoscales, respectively, by the same experienced observer. The wrinkle score increased with age in all eight areas of the face examined in Caucasian females as well as in Japanese females. In the group aged 20-29 years, the wrinkle score in each area was significantly higher in Caucasian females than in Japanese females. The wrinkle scores in the forehead, glabella, upper eyelid, and corner of the eye were similar at advanced ages between the two groups, while the wrinkle scores in lower areas of the face (lower eyelid, nasolabial groove, cheek, and corner of the mouth) were markedly higher in Caucasian females than in Japanese females in each age group, and reached an upper limit at advanced ages in Caucasian females. The sagging score also increased with age in Caucasian females as well as in Japanese females. The sagging score was significantly higher in Caucasian females than in Japanese females in the groups aged 40 years or more. These results suggest more marked wrinkle formation in all areas of the face in younger age groups of Caucasian females living in North America than in Japanese females living in Tokyo. In particular, Caucasian females showed marked age-related wrinkle formation in the lower areas of the face, probably due to sagging in the subzygomatic area, which suggests a higher susceptibility to sagging in the subzygomatic area of Caucasian females.

66 citations


Journal ArticleDOI
TL;DR: The results indicate that there are several simple, cheap, and effective methods, such as gel electrophoresis, that provide excellent information on collagen quality.
Abstract: Collagen is an important component for cosmetic formulation, where it is an effective natural humectant with high substantivity. Commercial collagen preparations have a wide range of properties. In the present study, various techniques have been used to examine three distinct commercial collagens that illustrate the range of properties that are available. The usefulness of the various techniques for assessing collagen quality and batch-to-batch variation is discussed. The results indicate that there are several simple, cheap, and effective methods, such as gel electrophoresis, that provide excellent information on collagen quality. The appropriate selection of tests allows informed decisions on the choice of which collagen preparation to use to provide the desired functionality and shelf life of a formulation.

41 citations


Journal ArticleDOI
TL;DR: The current understanding of the effect of ultraviolet (UV) radiation and visible light on the structure and integrity of human hair fibers and current and past approaches to the protection of hair from UV rays are described.
Abstract: This article describes the current understanding of the effect of ultraviolet (UV) radiation and visible light on the structure and integrity of human hair fibers; furthermore, it discusses current and past approaches to the protection of hair from UV rays. Relevant literature is reviewed.

39 citations


Journal ArticleDOI
TL;DR: Fibers subjected to repeated curling in the dry condition show slight increases in tensile mechanical properties, characteristic of a crosslinked fiber, and conditioners treated with conditioners show an improvement in characteristic life.
Abstract: The effect of curling hair with a curling iron has been investigated. Possibilities of thermal damage with repeated curling according to, and in violation of, the manufacturer's specifications have been studied. The propensity of hair surface to damage depends on the moisture content of the hair, and these experiments have been conducted in both wet and dry conditions, with and without application of tension, and with short or prolonged times. Scanning electron microscopic (SEM) examination revealed that fibers treated under the dry condition (50% RH) show radial and axial cracking along with scale edge fusion. Similar thermal treatment on wet hair resulted in severe damage of the type described above, as well as bubbling and buckling of the cuticle due to the formation and escaping of steam from the fiber. Fibers subjected to repeated curling in the dry condition show slight increases in tensile mechanical properties, characteristic of a crosslinked fiber. Fibers treated with conditioners show an improvement in characteristic life, especially in the case of low-molecular-weight conditioners, such as CETAB, which can penetrate into the hair fiber (shown by TOF-SIMS analysis).

34 citations


Journal Article
TL;DR: When UVB radiation was filtered, no breaking strength reduction was observed, indicating that changes in hair mechanical properties are mainly related to that range of the solar spectrum.
Abstract: The aim of this study was to compare the effects of sun exposure and bleaching treatments on hair mechanical properties. Tresses of virgin dark-brown hair were initially washed with lauryl sodium sulfate solution. Sun irradiation was simulated with xenon (full radiation) or mercury-vapor (full or UVB-filtered radiation) lamps. Hair was bleached using a commercial persulfate-peroxide solution. Stress/strain data were obtained from 20 fibers of each sample using a universal test machine. Breaking elongation and breaking strength were the main parameters affected by both treatments. Reduction in the breaking strength was observed for the photo-oxidized and bleached hair (compared to untreated samples). A reduction in the breaking elongation was also observed for the photo-oxidized samples. On the other hand, an increased tendency in this parameter was observed for the bleached hair. In relation to the radiation source, similar results were achieved with much less exposure time to a xenon lamp compared to a mercury-vapor lamp. When UVB radiation was filtered, no breaking strength reduction was observed, indicating that changes in hair mechanical properties are mainly related to that range of the solar spectrum.

30 citations


Journal Article
TL;DR: An o/w microemulsion formulated using lecithin and an alkyl glucoside as mild, non-irritant surfactants was proposed as a cosmetic vehicle for arbutin and kojic acid, naturally occurring whitening agents, and only in some cases did the presence of odorous molecules appear to influence it.
Abstract: An o/w microemulsion formulated using lecithin and an alkyl glucoside as mild, non-irritant surfactants was proposed as a cosmetic vehicle for arbutin and kojic acid, naturally occurring whitening agents. After assessing the physicochemical stability of the microemulsion in the presence and absence of whitening agents, several perfumed compositions, developed using fragrant molecules of natural or synthetic origin, were introduced, and the olfactory impact of the perfumed microemulsion was evaluated. The photostability to UVB irradiation of both whitening agents was determined in aqueous solutions and in microemulsions, and also in the presence of the perfumed compositions. The stability of arbutin and kojic acid was higher in microemulsions than in aqueous solutions, and only in some cases did the presence of odorous molecules appear to influence it: linalool exerted some protective effect towards kojic acid photodegradation.

29 citations


Journal Article
TL;DR: The results of this study suggest that the type of silicone emulsifier used to prepare sunscreen emulsions should be carefully chosen in order to prevent the percutaneous absorption of sunscreens from these cosmetic formulations.
Abstract: The effects of different silicone emulsifiers on the in vitro permeation through human skin of two sunscreens (octylmethoxycinnamate, OMC, and butylmethoxydibenzoylmethane, BMBM) were investigated from cosmetic emulsions. The formulations being tested were prepared using the same oil and aqueous phase ingredients and the following silicone emulsifiers: dimethicone copolyol and cyclomethicone (emulsion 1), cetyldimethicone copolyol (emulsion 2), polyglyceryl-4-isostearate and cetyldimethicone copolyol and hexyllaurate (emulsion 3), lauryldimethicone copolyol (emulsion 4), and cyclomethicone and dimethicone copolyol (emulsion 5). The cumulative amount of OMC that permeated in vitro through human skin after 22 h from emulsions 1-5 decreased in the order 2 approximate, equals 1 > 5 > 4 approximate, equals 3 and was about twofold higher from emulsion 2 compared to emulsion 4. As for BMBM, no significant difference was observed in regard to its skin permeation from the emulsions being tested. In vitro release experiments of OMC and BMBM from emulsions 1-5 were performed through cellulose acetate membranes using Franz diffusion cells. Emulsions 1-3 showed an initial slow release of BMBM followed by a fast release phase, while the release of OMC showed a different pattern since the sunscreen was released very rapidly at the beginning of the experiment and then a plateau was observed followed by a second step of fast release. A pseudo-first-order release rate was observed only for BMBM from emulsion 4, while emulsion 5 released very small amounts of both sunscreens during 22 h. These findings could be attributed both to changes in sunscreen thermodynamic activity in the vehicle and to modified interactions between the active ingredient and the formulation components. The results of this study suggest that the type of silicone emulsifier used to prepare sunscreen emulsions should be carefully chosen in order to prevent the percutaneous absorption of sunscreens from these cosmetic formulations.

28 citations


Journal ArticleDOI
TL;DR: High-resolution HPLC analysis showed that encapsulated systems such as Lipotec nanocapsules, Tagravit A1 microcapsules, phosphatidylcholine liposomes, and Lipotac liposome protect the vitamin A ester over time from hydrolysis and from oxidation to retinaldeide and retinoic acid, and that Lipotic nanocapules and phosphatidscholineliposomes improve the vitamin's photostability.
Abstract: Vitamin A palmitate photostability in relation to UVA and UVB was tested in hydroxy ethyl cellulose hydrogels at pH 4.0, 5.6, 7.0, and 8.0, alone and with the addition of sunscreens (3,4-methylbenzilidencamphor or butyl methoxy dibenzoylmethane) or an antioxidant (butylated hydroxy toluene). The photostability of vitamin A palmitate was also tested in encapsulated systems (Tagravit A1 microcapsules, Lipotec liposomes, phosphatidylcholine liposomes, and Lipotec nanocapsules) dispersed in gels at pH 5.6 and 7.0. The stability of retinyl palmitate over time in hydroxy ethyl cellulose hydrogels at pH 5.6 and 7.0 (stored one month at 25 degrees C or 40 degrees C), alone or with butylated hydroxy toluene, was also tested. The stability of retinyl palmitate over time in encapsulated systems, dispersed in gels at pH 5.6 and 7.0, was also studied. O/W emulsions were also prepared to compare the stability of vitamin A palmitate introduced in a lipophilic/hydrophilic medium (O/W emulsions) and a hydrophilic medium (hydrogels). HPLC analysis showed that encapsulated systems such as Lipotec nanocapsules, Tagravit A1 microcapsules, phosphatidylcholine liposomes, and Lipotec liposomes protect the vitamin A ester over time from hydrolysis and from oxidation to retinaldeide and retinoic acid, and that Lipotec nanocapsules and phosphatidylcholine liposomes also improve the vitamin's photostability. A change in pH (from 5.6 to 7.0) of the gels did not influence the vitamin ester's stability. pH levels of 4.0 and 8.0 determined a decrease in the stability of retinyl palmitate in the gels. A high concentration of sunscreens improved the photostability of retinyl palmitate in the gels at pH 5.6 and 7.0. Butylated hydroxy toluene protected retinyl palmitate from degradation induced by light at all the pH levels studied and by heat at pH 5.6 and 7.0, as can be seen from the study of the photostability of vitamin A palmitate under UVB and UVA and of stability over time. Rheological studies showed a slight decrease in the viscosity of the gels after UVB-UVA irradiation and a higher decrease in the viscosity of the gels and the emulsions after storage at 25 degrees C and 40 degrees C. This decrease can be attributed to a partial degradation of hydroxy ethyl cellulose and of emulsifier, as can be seen from the decrease in shear stress versus shear rate values under these conditions of storage, denoting a depolymerization of the rheological modifier.

Journal ArticleDOI
TL;DR: An attempt has been made to differentiate between specular and diffuse reflectance by analyzing mathematically goniophotometric curves of light reflected from unaltered single hair fibers from European, African, and Asian ethnic groups.
Abstract: One of the most desirable hair attributes to consumers, irrespective of ethnic background, is hair shine. The light reflected from a fiber has two components, specular and diffuse. The specular fraction of reflected light from the front surface of the fiber is generally recognized as a contributor to high luster. The distinction between specular and diffuse reflection is, however, not always clearly defined. In this study an attempt has been made to differentiate between specular and diffuse reflectance by analyzing mathematically goniophotometric curves of light reflected from unaltered single hair fibers from European, African, and Asian ethnic groups. The effect of macroscopic characteristics of the hair fibers, such as fiber diameter, cross-sectional shape, and curvature on luster is demonstrated. Results indicate that broadening of the specular peak reduces luster values, and is related to these characteristics. Thus, specular peak broadening is one of the important features to take into account when evaluating luster. Therefore, a new method for luster evaluation from goniophotometric curves is proposed. Additionally, we present the general model for light scattering, showing how scattering by surface roughness of different origin and magnitudes, and the scattering and absorption processes by the hair's interior, affect the position of the specular reflectance peak and its broadening.

Journal ArticleDOI
TL;DR: A model of the CMC is presented, based on prior research, in which interconnecting bonds between the layers are proposed to assist in the interpretation of hair-fracturing mechanisms for cuticle chipping, deep transverse cuticle cracks, cracks during heat drying, scale lifting by surfactants, and catastrophic failure.
Abstract: Although adhesion failure in hair fibers can occur inside cells, it occurs more frequently in the cell membrane complex (CMC), often involving the rupture of interlayer bonds. Therefore, a model of the CMC is presented, based on prior research in which we propose interconnecting bonds between the layers to assist in our interpretation of hair-fracturing mechanisms for cuticle chipping, deep transverse cuticle cracks, cracks during heat drying, scale lifting by surfactants, and catastrophic failure. Failure in the wet state generally involves hydrophilic layers, e.g., the contact zone of the CMC or the endocuticle or bonding to these hydrophilic layers, whereas failure in the dry state generally involves bonding between hydrophobic layers, e.g., beta-delta failure. Chemical damage by perms, bleaches, and sunlight, by breaking specific chemical bonds, influences the sites of initial failure and increases the number of routes for crack propagation, leading to more complex fracture patterns.

Journal ArticleDOI
Linda D. Rhein1, Bhaskar Chaudhuri, Nur Jivani, Hani Fares1, A.F Davis1 
TL;DR: In this paper, a polyurethane polymer (polyolprepolymer-15) was found to be an effective agent in controlling delivery of salicylic acid to the epidermis and reducing the rapid early penetration of large amounts of drug through the skin.
Abstract: Salicylic acid (SA) is a beta hydroxy acid and has multifunctional uses in the treatment of various diseases in skin such as acne, psoriasis, and photoaging. One problem often cited as associated with salicylic acid is that it can be quite irritating at pH 3-4, where it exhibits the highest activity in the treatment of skin diseases. We have identified strategies to control the irritation potential of salicylic acid formulations and have focused on hydroalcoholic solutions used in acne wipes. One strategy is to control the penetration of SA into the skin. Penetration of the drug into various layers of skin, i.e., epidermis, dermis, and receptor fluid, was measured using a modified Franz in vitro diffusion method after various exposure times up to 24 hours. A polyurethane polymer (polyolprepolymer-15) was found to be an effective agent in controlling delivery of SA. In a dose-dependent fashion it targeted delivery of more SA to the epidermis as compared to penetration through the skin into the receptor fluid. It also reduced the rapid rate of permeation of a large dose of SA through the skin in the first few hours of exposure. A second strategy that proved successful was incorporation of known mild nonionic surfactants like isoceteth-20. These surfactants cleanse the skin, yet due to their inherent mildness (because of their reduced critical micelle concentration and monomer concentration), keep the barrier intact. Also, they reduce the rate of salicylic acid penetration, presumably through micellar entrapment (either in solution or on the skin surface after the alcohol evaporates). Cumulative irritation studies showed that targeting delivery of SA to the epidermis and reducing the rapid early rate of penetration of large amounts of drug through the skin resulted in a reduced irritation potential. In vivo irritation studies also showed that the surfactant system is the most important factor controlling irritancy. SA delivery is secondary, as formulations with less SA content reduced the rate of delivery to the receptor and yet were some of the most irritating formulations tested, presumably due to the action of the specific anionic surfactant on the barrier. Alcohol content also did not appreciably affect irritation and SA delivery; formulations with considerably lower alcohol content but containing anionic versus nonionic surfactant systems exhibited considerably higher irritancy. Thus the surfactant type was again the predominant factor in those studies, although arguably alcohol plays some role (solubilization of SA). Results showed that both polymers and mild surfactants work in concert to provide the optimal formulation benefits of targeted delivery and reduced irritation. Synergistic relationships among hydroalcoholic formulation components will be discussed along with the mechanisms likely involved in controlling delivery of SA to skin.

Journal ArticleDOI
TL;DR: The gloss index as a physically consistent measure of hair luster is derived from the ratio of the integral intensities of the light components, as measured by laser-based, multiangle goniophotometry, presented in Part I.
Abstract: Hair shine or luster is perceived as an important, though analytically somewhat elusive, attribute of beauty, primarily associated with clean and healthy hair. Principles for the assessment of hair luster are developed that are consistent with the practical situation. These principles are related to the components of light, specularly and diffusely reflected from single hair fibers, as measured by laser-based, multiangle goniophotometry, presented in Part I. Considering various definitions of gloss, their tradition, practical implementation, and their inherent limitations for testing hair, the gloss index as a physically consistent measure of hair luster is derived from the ratio of the integral intensities of the light components. Changes of the parameter values along hair length, namely their decrease, are analyzed for hairs of different color and ethnic origin. The correlation with shine evaluations of hair tresses by panels, based on literature data, is analyzed and ascertained.

Journal Article
TL;DR: It is concluded that DSC could be used to identify appropriate vehicles for drugs whose follicular delivery depends on solubility, and that either increasing the volume of the oil phase or changing the emulsion to a water-in-oil emulsion would increase follicular deposition.
Abstract: In an earlier paper, we identified vehicles that are miscible with sebum, using differential scanning calorimetry (DSC). In this paper, the potential of these vehicles to deliver salicylic acid (SA) into the sebum-filled follicles of hamster ears is examined. The main objective of this study is to correlate the melting transitions of a model sebum with the follicular delivery of SA, using two different types of vehicles (fatty and polar). Generally, the fatty vehicles show higher deposition than the polar vehicles. Follicular delivery of salicylic acid correlates well with its solubility in the respective vehicles. This extent of deposition also shows a relationship with the effect of the vehicle on thermal behavior of the model sebum. The nature of the relationship depends on the vehicle (polar or fatty) tested. We conclude that DSC could be used to identify appropriate vehicles for drugs whose follicular delivery depends on solubility. The results also suggest that delivery into the sebaceous glands occurs by two different mechanisms, depending upon the polarity of the vehicle and the physicochemical properties of the drug. The results of these experiments are further extended to investigate follicular delivery of SA from two different types of oil-in-water emulsion formulations. From these studies we conclude that either increasing the volume of the oil phase or changing the emulsion to a water-in-oil emulsion would increase follicular deposition. Our research highlights the role of sebum, its compatibility with drug molecules, and vehicle selection in the transport of drugs into the follicles. The overall results of these experiments provide a reasonable understanding of the mechanisms underlying the transport of drugs to, and subsequently through, the sebaceous follicle.

Journal ArticleDOI
TL;DR: The objective of this research was the application of headspace (HS)-solid-phase microextraction (SPME) for the quantitation of formaldehyde present in raw materials and cosmetic formulations.
Abstract: The objective of this research was the application of headspace (HS)-solid-phase microextraction (SPME) for the quantitation of formaldehyde present in raw materials and cosmetic formulations. The formaldehyde was derivatized in situ first with pentafluorophenylhydrazine (PFPH), to form a derivative hydrazone. The formed hydrozone was adsorbed on a SPME fiber during headspace extraction under controlled conditions (time, temperature, volume, etc.). After the adsorption step, the SPME fiber was directly transferred into the gas chromatography (GC) injection port in which the analytes were thermally desorbed. Deuterated acetone was used as an internal standard (IS) in order to quantitate the formaldehyde content. For the experiment, a gas chromatograph equipped with a flame ionization detector (GC/FID) was employed. A gas chromatograph/mass spectrometer (GC/MS) was used for the qualitative confirmation of results in this work.

Journal Article
TL;DR: The results reported here indicate that vitamin E in the superficial layers of the SC is depleted readily by even a brief exposure to sunlight and that use of a vitamin E body wash can substantially increase theitamin E in this superficial layer more effectively than dietary supplementation.
Abstract: Topical supplementation represents an attractive approach to mitigate environmentally induced deficiencies of skin vitamin E (alpha-tocopherol). We report here the impact of natural sunlight on stratum corneum (SC) vitamin E and also compare the effectiveness of dietary supplementation to topical application as a way to increase vitamin E in the superficial layers of the SC. The effects of natural sunlight, 30 minutes of midday sunlight, were measured on two separate occasions. Vitamin E in the surface layers of the SC was measured by HPLC after ethanol extraction. Under these relevant conditions, vitamin E in the superficial SC was reduced in a dose-dependent manner by 50-65%. In a followup study, panelists entered into a randomized, double-blind, vehicle-controlled study. In this study, one group washed their skin once daily for one minute with a commercially available body wash containing 0.15% vitamin E and 0.10% vitamin E acetate, while the second group used a body wash without vitamin E but also supplemented their diet with 400 IU alpha-tocopherol (18 x RDI). Not surprisingly, only dietary supplementation increased serum vitamin E (approximately twofold). Although both treatment modalities increased SC vitamin E, topical delivery was significantly more effective (53-fold vs baseline) than dietary delivery (eightfold vs baseline). Moreover, only topical delivery increased SC vitamin E acetate (19-fold vs baseline). The results reported here indicate that vitamin E in the superficial layers of the SC is depleted readily by even a brief exposure to sunlight and that use of a vitamin E body wash can substantially increase the vitamin E in this superficial layer more effectively than dietary supplementation.

Journal ArticleDOI
TL;DR: Details of the specular reflection of curved hair tresses, resulting from illumination with a collimated incident light source, were examined both qualitatively and quantitatively using high-resolution photography and image analysis.
Abstract: Details of the specular reflection of curved hair tresses, resulting from illumination with a collimated incident light source, were examined both qualitatively and quantitatively using high-resolution photography and image analysis. The reflections were found to consist of a multitude of light dots aligned with the fibers and typically separated by a distance of 81-145 lam. The contrast between the dots (specular reflection) and the darker regions (diffuse reflection) of the entire reflection band was found to increase with increasing pigmentation of hair. Highly pigmented Oriental hair provided more contrast within the specular reflection band than unpigmented natural white hair. A quantitative description of the light reflection patterns within the specular reflection band included two-dimensional distribution of luminosity, histograms of the frequency of appearance for peak maxima and minima in luminosity distribution plots, and histograms of absolute maxima and minima of luminosity along the length of the fibers. Specular reflection from African hair, which consists of many curls that provide multiple and randomly distributed reflection centers, have also been investigated. Using microscopy software, Image Tool 2.0, and a method termed image threshold, the number of reflection sites and their shapes could be quantified. For example, treatment of African hair with synthetic sebum was shown to significantly affect the reflection patterns, resulting in a decrease in the overall hair luster. Comparison of reflection patterns from Caucasian frizzy, very curly, and curly hair is also discussed.

Journal ArticleDOI
TL;DR: It was determined that irritation levels of the evaluated test materials varied markedly with respect to product category, type of ocular irritation, and ocular tissue, demonstrating that these factors are important considerations for the prediction of the ocular irritancy of a test material.
Abstract: The assessment of ocular irritation potential is an important part of safety testing for cosmetic and consumer products. The purpose of this investigation was to examine ocular irritancy levels elicited in humans by various categories of a specific class of cosmetic and consumer products that have a potential to enter the eye inadvertently during use. Test materials assessed belonged to one of seven categories, which included liquid makeup, shampoo, baby wash, mascara, eye makeup remover, powder eye shadow, and facial cleanser. These test materials were evaluated by human ocular instillation, followed by examinations, for which subjective perceptions of irritation were recorded, and component areas of ocular tissues were individually examined for inflammation and for the area and density of fluorescein staining patterns at 30 seconds and at 5, 15, 60, and 120 minutes post-instillation. Subjective and objective ocular irritation scores of 410 eyes were analyzed by product classification. Average score levels were determined for subjective responses, inflammation, and fluorescein staining patterns. This investigation determined that irritation levels of the evaluated test materials varied markedly with respect to product category, type of ocular irritation, and ocular tissue, demonstrating that these factors are important considerations for the prediction of the ocular irritancy of a test material.

Journal Article
TL;DR: The quartz-crystal microbalance (QCM), utilized successfully for the first time to study the salivary film, has shown the possibility of an alternate accumulation mechanism by which the surface charges on the film are effectively reversed by the opposite charged proteins.
Abstract: The salivary film or the acquired pellicle is a protein film formed initially on the enamel surface of teeth. Such a film plays an important role in enamel protection, but is also an initial substructure for the formation of plaque and the cosmetically undesirable colored stain. The composition and the structure of the film are still essentially unknown because of the difficulty of its isolation for characterization. The purpose of this study was to investigate the effect of some metal cations on the salivary film or the pellicle formation, and also to clarify the mechanism of development. First, using infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS), the in situ-formed film in the mouth was confirmed to contain selectively adsorbed well-known proteins. Then, in vitro studies have demonstrated that Ca2+ ions enhance film formation at the initial stage in virtue of Ca bridging and, interestingly, that Mg2+ ions oppositely inhibit the formation. Furthermore, the quartz-crystal microbalance (QCM), utilized successfully for the first time to study the salivary film, has shown the possibility of an alternate accumulation mechanism by which the surface charges on the film are effectively reversed by the opposite charged proteins.

Journal ArticleDOI
TL;DR: The toF-SIMS data indicate higher levels of conditioner on the bleached hair relative to the undamaged hair, and the more non-polar surfactant components have greater substantivity for the fiber surface, as indicated by the relative increase in their ToF- SIMS intensity.
Abstract: In this study the applicability of the surface-sensitive Time-of-flight secondary ion mass spectrometry (ToF-SIMS) technique to hair analysis and associated aqueous processing is evaluated. ToF-SIMS analysis of ‘as received’ human hair indicates the presence of silicones, anionic surfactants, and cationic conditioners, from previous treatments, on the fiber surface. Cleaning of the hair with SLS or SLES results in adsorption of the surfactants onto the fiber surface. In particular, the more non-polar surfactant components have greater substantivity for the fiber surface, as indicated by the relative increase in their ToF-SIMS intensity. Application of the Incroquat Behenyl 18-MEA conditioner to both ‘virgin’ and bleached hair results in the adsorption of the cationic C18, C20, C22, and C21 surfactant components onto the hair surface. The ToF-SIMS data indicate higher levels of conditioner on the bleached hair relative to the undamaged hair.

Journal ArticleDOI
TL;DR: It is proven that visible (VIS) and UV light attack different sites of the melanin granule, even though the lightening rates from both light sources are similar.
Abstract: In this study the photolightening behavior of blond hair was investigated. The results demonstrated that visible (VIS) and ultraviolet (UV) light lighten blond hair through different mechanisms. VIS light was found to contribute much more to the lightening of blond hair than UV light, and acted directly, while UV light only lightened blond hair that had been washed following irradiation. VIS and UV light both, however, lightened to a similar degree isolated melanin granules and decomposed melanin granules that were exposed on a cross section of blond hair. These results indicate that melanin granules are equally sensitive to both forms of light while blond hair is most sensitive to VIS light. The results also indicate that hair tissues, excluding melanin granules, are damaged by UV light but not by VIS light. Based on these facts, the hypothetical lightening mechanism of UV light is assumed to be that UV light preferentially attacks and damages hair tissues rather than melanin granules. This occurs only after the hair is washed, as the washing process removes the melanin granules that effuse from loose hair fibers. In contrast, VIS light preferentially attacks and decomposes the melanin granules rather than other tissues, and also results in the lightening of blond hair but without the need for subsequent washing. We also found that while VIS light destroys the structure of isolated melanin granules, UV light does not act in a similar manner. Consequently, it is proven that VIS and UV light attack different sites of the melanin granule, even though the lightening rates from both light sources are similar.

Journal Article
TL;DR: Melanin degrading extracts isolated from Aspergillus fumigatus and Saccharomyces cerevisiae were applied to human skin and cause significant reduction in UVB induced pigmentation and may be useful in developing new whitening products to even skin color and tone.
Abstract: The biochemical synthesis of human melanin is understood in some detail. However, little is known about melanin degradation and catabolism of melanin. We hypothesize that human skin contains enzymes that degrade melanin and these enzymes can be used to reduce skin color. To test this hypothesis, HaCaT keratinocytes and normal human keratinocytes in culture were pulse labeled for one hour with radiolabeled synthetic melanin. This melanin was synthesized in vitro using tyrosinase enzyme from mushrooms and using radiolabeled [14C]3,4-dihydroxyphenylalanine (DOPA) as a substrate. After the initial pulse labeling, samples of both the cells and media were taken at 2, 4, 6 and 18 hours. Over these time periods the counts remaining in the media and cell fraction were significantly decreased. This data suggests the need for new protein synthesis and the lysosome organelle function for the degradation. Melanin degrading extracts isolated from Aspergillus fumigatus and Saccharomyces cerevisiae were applied to human skin. These extracts cause significant reduction in UVB induced pigmentation. These extracts may be useful in developing new whitening products to even skin color and tone.

Patent
TL;DR: In this article, an in vitro method for the prediction of in vivo UVA protection by a composition with sunscreen properties was proposed, which includes the steps of determining in vivo SPF : determining in vitro SPF based on the sunscreen's absorbance spectrum in the UV region; normalizing the absorbence spectrum based on integration area of UVA1; and calculating the PFA-PPD in vitro.
Abstract: An in vitro method for the prediction of in vivo UVA protection by a composition with sunscreen properties. The method includes the steps of : Determining in vivo SPF : determining in vitro SPF based on the sunscreen’s absorbance spectrum in the UV region; normalizing the absorbence spectrum based on integration area of UVA1; and calculating the PFA-PPD in vitro.