Alterations promoted by acid straightening and/or bleaching in hair microstructures.

Human hair is a biopolymer constituted mainly of keratin intermediate filaments, lipids, pigments and water. Cosmetic treatments usually interact with the hair at the molecular level, inducing changes in its components and modifying the physicochemical and mechanical properties of the fibers. Here, the effect of acid straightening on the morphology and ultrastructure of Caucasian hair was investigated by a group of complementary experimental methods: wide-, small- and ultra-small-angle X-ray scattering; high-resolution 3D X-ray microscopy; quasi-elastic neutron scattering and inelastic neutron scattering; thermogravimetry-mass spectrometry; and differential scanning calorimetry (DSC). X-ray diffraction patterns showed that acid straightening associated with a flat iron (∼180°C) changed the cortex of the fiber, shown by denaturation of the intermediate filaments (measured by DSC). The increase in the spacing of the lipid layers and the observation of the dehydration behavior of the fiber provided indications that water may be confined between these layers, while neutron spectroscopy showed alterations in the vibration mode of the CH2 groups of the lipids and an increase of the proton (H+) mobility in the hair structure. The latter may be associated with the extremely low pH of the formulation (pH ≃ 1). Additionally, this investigation showed that bleached hair (one-time bleached) is more damaged by the action of acid straightening than virgin hair, which was shown by a threefold increase in the percentage of total porosity of the tresses. The obtained results demonstrate that the investigation approach proposed here can provide very important thermodynamic and structural information on induced changes of hair structure, and certainly can be applied for the evaluation of the action mode and efficiency of cosmetic treatments.

Nanoemulsions containing plant oils: How do they influence hair treatment?

OBJECTIVE: Cosmetic and dermatological products, mainly the hair treatments, are projected to have remarkable growing in coming years. Nanotechnology, specifically nanoemulsions, has potential to be used in several hair products, owing to their beneficial properties. Concurrently, plant-derived cosmetics have become more popular over the years to consumers who prefer a safer, natural and sustainable approach. There is a lack of studies combining plant oils and nanotechnology for haircare formulations. In this work, different plant oil-loaded nanoemulsions were prepared to investigate the influence of their particle size, zeta potential and composition on hair treatment efficacy. METHODS: Coconut, olive and Abyssinian oils, alone or in combination, were loaded into nanoemulsions by high-pressure homogenization method (HPH). The mean particle size, polydispersity index and zeta potential were measured by the dynamic light scattering (DLS) method, and a stability test was performed for five months. A sensorial screening evaluation performed by the analyst and the combing test using Dia-Stron® instrumentation were applied on hair tresses treated by these nanoemulsions. RESULTS: The use of different plant oils for nanoemulsion resulted in distinct final particle sizes and zeta potential. However, results suggested no significant difference between them in hair tresses combing efficacy compared by Dia-Stron® instrument testing. Moreover, the plant-loaded nanoemulsions with increased concentration of cationic surfactant indicated a 50% reduction in combing force using this device when compared to control, in addition to better sensory results by screening test compared to other nanoemulsions and control. CONCLUSION: The composition of plant oils, particle size or zeta potential of the prepared nanoemulsions does not seem to significantly influence hair performance. Thus, we suggest that finding the right balance between cationic surfactant and plant oils may be the most appropriate path to develop effective nanoemulsions in hair treatment.

OBJECTIF: Les produits cosmétiques et dermatologiques, principalement les traitements capillaires, devraient connaître une croissance remarquable dans les années à venir. La nanotechnologie, en particulier les nanoémulsions, a le potentiel d'être utilisée dans plusieurs produits capillaires, en raison de leurs propriétés bénéfiques. Parallèlement, les cosmétiques d'origine végétale sont devenus plus populaires au fil des ans auprès des consommateurs qui préfèrent une approche plus sûre, naturelle et durable. Il existe un manque d'études combinant les huiles végétales et la nanotechnologie pour les formulations de traitement capillaire. Dans ce travail, différentes nanoémulsions contenant de l'huile végétale ont été préparées pour étudier l'influence de leur taille de particule, de leur potentiel zêta et de leur composition sur l'efficacité du traitement capillaire. MÉTHODES: Les huiles de noix de coco, d'olive et d'Abyssinie, seules ou en combinaison, ont été chargées dans des nanoémulsions par méthode d'homogénéisation à haute pression (HPH). La taille moyenne des particules, l'indice de polydispersité et le potentiel zêta ont été mesurés par la méthode de diffusion dynamique de la lumière (DLS), et un test de stabilité a été effectué pendant cinq mois. Une évaluation sensoriel réalisée par l'analyste et le test de peignage à l'aide de l'instrumentation Dia - Stron® ont été appliqués sur les cheveux traités par ces nanoémulsions. RÉSULTATS: L'utilisation de différentes huiles végétales pour la nanoémulsion a donné des tailles de particules finales et un potentiel zêta distinct. Cependant, les résultats n'ont suggéré aucune différence significative entre eux dans l'efficacité du peignage des cheveux par rapport aux tests d'instruments Dia-Stron®. De plus, la nanoémulsion chargée avec une concentration plus élevée de tensioactif cationique a indiqué une réduction de 50% de la force de peignage en utilisant ce dispositif par rapport au contrôle, et, le screening a montré de meilleurs résultats sensoriels par rapport aux autres nanoémulsions et contrôle. CONCLUSION: La composition des huiles végétales, la taille des particules ou le potentiel zêta des nanoémulsions préparées ne semblent pas influencer significativement les performances capillaires. Ainsi, nous suggérons que trouver le bon équilibre entre un tensioactif cationique et des huiles végétales peut être la voie la plus appropriée pour développer des nanoémulsions efficaces dans le traitement des cheveux.

Chemical and physical treatments damage Caucasian and Afro-ethnic hair fibre: analytical and image assays.

BACKGROUND: Sensory and structural characteristics of hair can be modified by chemical and physical treatments, as dyeing, brushing, but also by external factors, as sunlight radiation. However, quantitative data relating damage to the degree of hair curliness and treatments are missing. OBJECTIVE: To evaluate the effect of chemical and physical treatments on different types of hair. METHODS: In this study, we compared the effects of bleaching/dyeing, thioglycolate-based straightening, brushing/flat iron and UVA/Vis radiation on different types of hair: Caucasian (straight dark brown, straight blond, wavy dark brown and curly dark brown) and Afro-ethnic hair. RESULTS: Bleaching/dyeing and UVA/Vis radiation increased combing work of Afro-ethnic hair tresses, indicating damage to the cuticle scales, which was confirmed by SEM images. Further, bleaching/dyeing caused wear on cuticles with high protein loss and reduction on the tryptophan content, independently of the hair curliness, which characterizes those procedures as very aggressive to hair structure. Straightening using ammonium thioglycolate, due to the oxidative treatment evolved, caused significant colour fading in brown/black tresses, while UVA/Vis radiation affected the colour of only blond hair tresses since they are poor in eumelanin, the photoprotective and photostable melanin molecule. CONCLUSION: The combination of analytical and image techniques contributed to understanding how the hair shape is related to the type of damage caused by several chemical and physical treatments. These findings contribute to the development of safety cosmetics that insure the beauty of curly hair, both Caucasian and Afro-ethnic hair.

Main features and applications of organogels in cosmetics.

Cosmetic treatments aim at improving skin appearance through vehicles of good sensory properties. Those vehicles are mainly emulsions and gels designed to deliver safe and effective compounds to skin. Creams and serums are widely used to achieve these goals, but recently a new type of formulation known as organogels triggered scientific attention, particularly in the design of both topical and cosmetic formulations. It has been established that the lipophilic nature of organogels makes it an excellent candidate for the delivery of cosmetic molecules through skin. In this review, we discuss the properties and characteristics of organogels and present the advantages of the application of these systems in cosmetics.

Les traitements cosmétiques visent à améliorer l'apparence de la peau grâce à des véhicules dotés de bonnes propriétés sensorielles. Ces véhicules sont principalement des émulsions et gels conçus pour livrer des composants sûrs et efficaces à la peau. Crèmes et sérums sont largement utilisés pour atteindre ces objectifs mais un nouveau type de formulation appelé organogels a récemment attiré l'attention des scientifiques, en particulier en ce qui concerne la conception de formulations à la fois topiques et cosmétiques. Il a été établi que la nature lipophile des organogels en fait d'excellents candidats pour la livraison de molécules cosmétiques à la peau. Dans cette analyse, nous discutons des propriétés et des caractéristiques des organogels, et présentons les avantages de l'utilisation de ces systèmes dans la cosmétique.

Rutin increases critical wavelength of systems containing a single UV filter and with good skin compatibility.

BACKGROUND/PURPOSE: Ultraviolet (UV) radiation is responsible for sunburns, skin cancer, photoaging, and the production of reactive oxygen species (ROS). The awareness on preventing these deleterious effects made the use of anti-UVB formulations an important part of population habits; however, despite the availability of several antioxidants capable of ROS scavenging, the pharmaceutical market lacks products associating UV filters with natural compounds of proven efficacy. Here, we investigated the effect of rutin, a flavonoid with antioxidant activity, associated with UVB filters in dermocosmetic preparations. METHODS: Formulations were assessed through its antioxidant activity, in vitro photoprotective effectiveness, photostability, and in vivo skin tolerance (hydration, transepidermal water loss, and erythema). RESULTS: Samples containing rutin were compatible with the human skin and presented a pronounced antioxidant potential, with scavenging activity values 75% higher than the ones containing only UVB filters. Although rutin could not prevent the sunscreens photodegradation post-irradiation, the bioactive compound significantly increased the formulations critical wavelengths, showing a photoprotective gain, especially in the UVA range. CONCLUSION: In conclusion, the absorption in the UVA range, coupled with ROS scavenging potential, proved the positive effect of rutin applied to anti-UVB formulations, making this bioactive compound a promising candidate for photoprotection improvement.

Short-term clinical of peel-off facial mask moisturizers.

OBJECTIVE: This study aimed to compare the efficacy of a peel-off facial mask based on polyvinyl alcohol (PVA) with an oil-in-water (o/w) emulsion and the effect of a soybean extract fermented by Bifidobacterium animale incorporated in those formulations (5% w/w). METHODS: The formulations were submitted to randomized clinical studies in volunteers to evaluate the measurement effects as (a) tensor by Cutometer® , (b) moisturizing by Corneometer® and transepidermal water loss (TEWL) by Tewameter® . These effects were determined in a short-term study (3 h) in a controlled-temperature room. RESULTS: The tensor effect and TEWL values indicated no significant difference between the use of facial mask and emulsion. On the other hand, the moisturizing effect of the facial mask on the stratum corneum was more significant than that of the emulsion according to Corneometer® measurements. Biometric cutaneous evaluation of peel-off facial masks (short-term study) showed that the masks promoted moisturizing effect of the stratum corneum more effectively than the oil-in-water emulsions. Thus, the facial masks were more efficient than emulsions in relation to moisturizing effects, but this efficiency is not related to the presence of fermented soybean extract. CONCLUSION: The results indicated that peel-off facial masks increase skin hydration in a process related to the occlusive effect.

Study of sunless tanning formulas using molted snake skin as an alternative membrane model.

Sunless tanning formulas have become increasingly popular in recent years for their ability to give people convincing tans without the dangers of skin cancer. Most sunless tanners currently on the market contain dihydroxyacetone (DHA), a keto sugar with three carbons. The temporary pigment provided by these formulas is designed to resemble a UV-induced tan. This study evaluated the effectiveness of carbomer gels and cold process self emulsifying bases on skin pigmentation, using different concentrations of a chemical system composed of DHA and N-acetyl tyrosine, which are found in moulted snake skins and their effectiveness was tested by Mexameter(®) MX 18. Eight different sunless tanning formulas were developed, four of which were gels and four of which were emulsions (base, base plus 4.0%, 5.0% and 6.0% (w/w) of a system of DHA and N-acetyl tyrosine). Tests to determine the extent of artificial tanning were done by applying 30 mg cm(-2) of each formula onto standard sizes of moulted snake skin (2.0 cm × 3.0 cm). A Mexameter(®) MX 18 was used to evaluate the extent of coloration in the moulted snake skin at T(0) (before the application) and after 24, 48, 72, 168, 192 and 216 h. The moulted snake skins can be used as an alternative membrane model for in vitro sunless tanning efficacy tests due to their similarity to the human stratum corneum. The DHA concentration was found to influence the initiation of the pigmentation in both sunless tanning systems (emulsion and gel) as well as the time required to increases by a given amount on the tanning index. In the emulsion system, the DHA concentration also influenced the final value on the tanning index. The type of system (emulsion or gel) has no influence on the final value in the tanning index after 216 h for samples with the same DHA concentration.

Novas metodologias analíticas para avaliação da eficácia fotoprotetora (in vitro) - revisão / New analytical methods for photoprotection effectiveness testing (in vitro) - a review

Atualmente, são utilizadas técnicas in vitro e in vivo para a avaliação do Fator de Proteção Solar (FPS) e do Fator de Proteção de UVA (FPA). O presente trabalho propõe a revisão das técnicas para as avaliações desses fatores in vitro preconizadas por FDA (Food and Drug Administration Agency) e COLIPA (European Cosmetic, Toiletry and Perfumery Association). O enfoque maior foi direcionado à análise espectrofotométrica de soluções diluídas e à espectrofotometria de reflectância com esfera integrada.

Currently, both in vitro and in vivo techniques are used to measure Sun Protection Factor (SPF) and UVA Protection Factor (APF). This paper reviews the in vitro techniques to test these factors, recommended by the FDA (USA Food and Drug Administration) and COLIPA (European Cosmetic, Toiletry and Perfumery Association). The main focus is on the spectrophotometric analysis of dilute solutions and the use of reflectance spectrophotometry with an integrating sphere.

Avaliação da interação de compostos ativos hidratantes com modelo de biomembrana de Crotalus durissus por meio de calorimetria exploratória diferencial e espectroscopia RAMAN / Study of the interaction of moisturizers with a Crotalus durissus biomembrane by differential scanning calorimetry and RAMAN spectroscopy

O objetivo foi verificar as alterações no estrato córneo em modelos alternativos de membrana após a aplicação de ativos hidratantes envolvendo métodos biofísicos. O modelo de biomembrana utilizado foi a muda de pele de Crotalus durissus e os ativos hidratantes foram: uréia, silício orgânico, extrato vegetal de Imperata cylindrica, reação de xilitol e glicose e componentes de NMF. Os resultados da avaliação das alterações do modelo por meio de Espectroscopia Raman com Transformada de Fourier sugerem que os ativos hidratantes confirmam segurança necessária, pois não alteraram de forma acentuada a estrutura do estrato córneo. Utilizando-se Calorimetria Exploratória Diferencial pode-se indicar que a solução de silício orgânico e o gel hidrofílico com uréia apresentaram melhor poder hidratante.

The objective of this research was to use biophysical techniques to investigate the alterations induced in a biomembrane model of the stratum corneum by the application of moisturizers. The biomembrane was obtained from the skin shed by the rattlesnake Crotalus durissus and the active moisturizing compounds were: urea, dimethylsilanol hyaluronate, Imperata cylindrical plant extract, carbohydrates and natural moisturizing factors (NMF components). Results from FT-Raman spectroscopy suggested that the moisturizers were safe, since they did not promote modifications in the structure of the stratum corneum. Differential scanning calorimetry results indicated that the solution containing the organic silicon compound and the gel with urea showed the best hydrating effects on the stratum corneum.

Double-blind, randomized, placebo-controlled trial of a cream containing the Stryphnodendron adstringens (Martius) Coville bark extract for suppressing terminal hair growth.

BACKGROUND: Excess of terminal hair can be defined as excessive hair that appears in male-like pattern in women. Some experts consider this condition as a result of an atypical relationship between levels of circulating androgens and sensitivity of androgen receptors in hair follicles to circulating androgens. AIMS: The aim of this research work was to evaluate the efficacy of a topical treatment for suppressing terminal hair growth of a cream containing 6.0% of the Stryphnodendron adstringens bark extract. STUDY DESIGN AND SUBJECTS: Study was randomized, double-blind and placebo-controlled. Subjects with excess of terminal hair were randomized to placebo and to the active treatment (cream with 6.0% of the extract). Evaluation was performed before and after 6 months, and subjects were photographed in each time. Clinical examination was carried out with the same physicians and in accordance with the Ferriman-Gallwey (FG) score. RESULTS: Benefits of the cream containing S. adstringens bark extract was observed in 60.98% (P < 0.001) of the subjects. FG score changed from 4 to 3 in the placebo group compared to 4-2 in the active. The cream suppressed the terminal hair growth and diminished the number of terminal hair. Subjects also described the reduction of skin hyperpigmentation, folliculitis and acne. Adverse events were not verified by physicians or patients. CONCLUSIONS: The cream with 6.0% of the S. adstringens bark extract was effective on the reduction and on the reversion of the terminal hair excess, being considered a new promissory product for such finality.

Desenvolvimento e Teste Preliminar da Estabilidade de formulações cosméticas acrescidas de extrato comercial de Trichilia catigua Adr. Juss (e) Ptychopetalum olacoides Bentham / Development and Preliminary Stability Testing of cosmetic formulations containing the commercial extract of Trichilia catigua Adr. Juss and Ptychopetalum olacoides Bentham

O presente estdo apresenta etapas de desenvolvimento de emulsões cosméticas, contendo 5% do extrato comercial de Trichilia catigua Adr. Juss (e) Ptychopetalum olacoides Bentham. Desenvolveram-se 14 formulações-teste e avaliou-se a obtenção de emulsões macroscopicamente estáveis, com valores de viscosidade aparente variados, pH compatível com o da pele e características organolépticas adequadas, por meio dos Testes de Estabilidade Preliminar e Acelerada. Estas formulações foram divididas em dois grupos: um com emulsões fluidas e outro com emulsões mais viscosas. Após análise, oito formulações-teste foram consideradas aptas para serem submetidas ao Teste de Estabilidade Preliminar. Após os ensaios, cinco formulações-teste foram selecionadas para o Teste de Estabilidade Acelerada. Os ensaios foram conduzidos em condições de armazenamento, de luminosidade e de temperatura extremas. Ao final do estudo, duas formulações-teste foram consideradas aprovadas por apresentarem os perfis mais estáveis durante o estudo, sendo ambas, emulsões fluidas constituídas de ceras auto-emulsionantes e 0,3% p/p de um polímero natural,e uma delas adicionada também de 2,0% lecitina de soja.

PAS-FTIR and FT-Raman qualitative characterization of sodium dodecyl sulfate interaction with an alternative stratum corneum model membrane.

The interaction of the surfactant sodium dodecyl sulfate with the stratum corneum (SC) of shed snake skin from Bothrops jararaca, used as a model membrane, was characterized qualitatively by FT-Raman and infrared photoacoustic (PAS-FTIR) spectroscopy, used as analytical tools. Surfactant solutions were 50.0 g x l(-1) and 2.34 g x l(-1) with treatment intervals of 4, 8 and 12 h. The employment of FT-Raman and PAS-FTIR indicated increased hydration of the SC with alteration of the tissue topography. The interaction of the SC with surfactant was increased by the tape-stripping process. The consequent exposure of the internal layers of the tissue intensified the effect of the anionic surfactant, indicating that this layer acted as an additional barrier.

Avaliação da estabilidade de máscaras faciais peel-off contendo rutina / Stability assessment of peel-off face masks containing rutin

Máscaras faciais peel-off baseiam-se em resinas vinílicas formadoras de filme. O álcool polivinílico (PVOH) é amplamente utilizado neste produto cosmético e interfere nas propriedades da película formada. A rutina, flavonóide da classe dos flavonóis, é empregadacomo potente antioxidante. O presente estudo contemplou como objetivo a avaliação da estabilidade física, físico-química e química de máscaras faciais peel-off contendo rutina, adicionada ou não de agente quelante, EDTA dissódico. Máscaras faciais peel-off foram desenvolvidas com 12,0% p/p de PVOH e 0,05% p/p de rutina. As amostras em estudo foram avaliadas quanto ao valor de pH, viscosidade aparente (cP) e teor da rutina remanescente nas amostras quantificada por espectrofotometria na derivada de primeira ordem a 410,0 nm, previamente validada; durante 45 dias nas seguintes condições de armazenamento: (1) 40,0 mais 0,5 ºC; (2) exposição à luz solar indireta e direta, à temperatura ambiente (22 mais 2 ºC); e (3) 5,0 mais 0,5 ºC. Verificou-se que a presença do EDTA Na2 (0,1% p/p) na formulação contribuiu para elevar a estabilidade da rutina nas condições de 22 mais ou menos 2 ºC e 5,0 mais ou menos 0,5 ºC. Sem a presença do agente quelante, o princípio ativo sofreu degradação em todas as temperaturas de armazenamento. Observou-se que valor de pH para ambas as preparações apresentou tendência para redução quando estas foram armazenadas a 40,0 mais ou menos 0,5 ºC, porém, não interferiu na estabilidade da rutina. Os resultados permitem concluir que o EDTA Na2 contribuiu para elevar a estabilidade do flavonóide na máscara facial peel-off elaborada com PVOH em condições consideradas normais e de temperaturas reduzidas de armazenamento (22 mais ou menos 2 ºC e 5,0 mais ou menos 0,5 ºC).