Characterization and Short-Term clinical study of clay facial mask / Caracterização e estudo clínico de curta duração de máscara facial argilosa

Clay mineral facial masks are used to treat some dermatological diseases, just for cleansing or reduce the amount of oil secreted by sebaceous glands. There are several types of clays, which vary in mineralogical and chemical composition, color and origin. However, the literature lacks studies involving clay facial masks, in particular regarding their influence on skin´s biomechanical properties. Thus, this work aimed to characterize colored clays and evaluate its influence on skin frmness and elasticity by a short-term clinical study. Different clays (named in this study magnesium aluminum silicate - MAS, white, pink and green) were chemically characterized, and facial mask formulations were prepared. The short-term clinical study was performed through the application of formulations on the skin. The skin frmness and elasticity were assessed before treatment and after mask removal. The statistical analysis showed no signifcant influence of time or formulations in those parameters, although volunteers reported the sensation of mechanical tension after the removal of the clay facial masks. Thus, the composition of the different clays did not affect the skin viscoelasticity behavior in the short-term clinical study, and a long-term use of this type of formulation must be indicated to observe all the expected benefts.(AU)

Máscaras faciais argilosas são utilizadas para tratar algumas doenças dermatológicas, apenas para a limpeza ou reduzir a quantidade de óleo secretado pelas glândulas sebáceas. Existem vários tipos de argilas, que variam em composição mineral, química, cor e origem. No entanto, a literatura carece de estudos envolvendo máscaras faciais argilosas, em particular em relação a sua influência nas propriedades biomecânicas da pele. Assim, este trabalho teve como objetivo caracterizar argilas coloridas e avaliar sua influência sobre a frmeza e elasticidade da pele por meio de um estudo clínico de curto prazo. Diferentes argilas (chamadas neste estudo de silicato de alumínio e magnésio - MAS, branca, rosa e verde) foram caracterizadas quimicamente, e formulações de máscaras faciais foram preparadas. O estudo clínico de curto prazo foi realizado por meio da aplicação das formulações na pele. A frmeza e elasticidade da pele foram avaliadas antes do tratamento e após a remoção da máscara. A análise estatística mostrou nenhuma influência signifcativa do tempo ou das formulações nesses parâmetros, embora os voluntários tenham reportado sensação de tensão mecânica, após a remoção das máscaras faciais argilosas. Assim, a composição das diferentes argilas não afetou o comportamento visco-elástico da pele no estudo clínico de curto prazo, e uma utilização de longa duração poderia ser indicada com a fnalidade de se observar todos os benefícios esperados.(AU)

Theoretical study of tautomers and photoisomers of avobenzone by DFT methods.

Organic ultraviolet (UV) filters such as cinnamates, benzophenones, p-aminobenzoic derivatives, and avobenzone (which have well-established and recognized UV-filtering efficacies) are employed in cosmetic/pharmaceutical products to minimize the harm caused by exposure of the skin to sunlight. In this study, a detailed investigation of the photostability and tautomerism mechanisms of avobenzone was performed utilizing DFT methods. The UV spectral profile of avobenzone was also simulated, and the results showed good agreement with experimental data. Furthermore, the calculations were able to distinguish tautomers and photoisomers of the studied organic filter based on their properties, thus showing the potential to develop new organic UV filters. Graphical Abstract Theoretical studies of avobenzone and its tautomers by TD-DFT.

Efficacy of Punica granatum L. hydroalcoholic extract on properties of dyed hair exposed to UVA radiation.

The solar radiation promotes color fading of natural and dyed hair by free radical generation, which oxidize the pigments, and it has been proposed the incorporation of antioxidants in order to reduce the alterations of hair color. Due to its high content of polyphenols and tannins, which are potent antioxidants, the hydroalcoholic extract of Punica granatum L. (pomegranate) was used in this research. Hair care formulations containing pomegranate extract were applied to red dyed hair tresses, and these were exposed to UVA radiation. Non-ionic silicone emulsion presenting color protection properties were also used for comparison purpose between the results obtained with different treatments, including silicone in combination with the pomegranate extract. The pomegranate extract at 5.0% and 10.0%w/w was effective in preventing the hair color fading in 37.6% and 60.8%, respectively, but the association of hydroalcoholic extract and non-ionic silicone emulsion is not encouraged. Mechanical properties were not affected by UVA radiation, since significant differences in breaking strength were not observed. Considering the conditions which the tresses have been exposed, it was concluded that the pomegranate extract at 10.0% w/w in hair care formulations are effective in reducing color fading of red dyed hair.

Influence of sodium metabisulfite and glutathione on the stability of vitamin C in O/W emulsion and extemporaneous aqueous gel.

Vitamin C exerts several functions on skin as collagen synthesis, depigmentant and antioxidant activity. Vitamin C is unstable in the presence of oxygen, luminosity, humidity, high temperatures and heavy metals, which presents a significant challenge to the development of cosmetic formulations. Therefore, the utilization of an effective antioxidant system is required to maintain the vitamin C stability. The purpose of this research work was to develop prototypes of cosmetic formulations, as O/W emulsion and extemporaneous aqueous gel, containing vitamin C and to evaluate the influence of sodium metabisulfite (SMB) and glutathione (GLT), as antioxidants, on the stability of the active substance. A HPLC stability-indicating method was developed and validated for this study and stability assays were performed in 90 and 26 days and storage conditions were 5.0+/-0.5, 24+/-2 and 40.0+/-0.5 degrees C. The HPLC stability-indicating method showed linearity (r(2)>0.99), specificity, R.S.D.<1.22% and accuracy/recovery ranging from 95.46 to 101.54%. Preparations with SMB or GLT and the antioxidant-free presented results statistically distinct, demonstrating the necessity of the antioxidant system addition. O/W emulsions with SMB or GLT retained the vitamin C content >90.38% stored at 5.0+/-0.5 and 24+/-2 degrees C. For the aqueous gel with SMB or GLT, the active substance concentration was maintained >94.03%. Considering the vitamin C stability, the SMB and the GLT showed to be statistically adequate, as antioxidants, for the cosmetic formulations.

Total flavonoids quantification from O/W emulsion with extract of Brazilian plants.

A new derivative spectrophotometric (DS) method was proposed and validated for quantification of total flavonoids from in O/W emulsion with polyacrylamide (and) C13-14 isoparaffin (and) laureth-7 containing Catuaba (Trichilia catigua Adr. Juss) (and) Marapuama (Ptychopetalum olacoides Bentham) extract. DS method was optimized to perform the assay in most favorable conditions. Linearity, specificity and selectivity, recovery (Rc, %), precision (R.S.D., %), accuracy (E, %), detection (LOD, microg ml(-1)) and quantification limits (LOQ, microg ml(-1)) were established for method validation. First-derivative at 388.0 nm (zero-to-peak; amplitude= +/- 0.12; wavelength range= 300.0-450.0 nm and Deltalambda = 4 nm) offered linearity for rutin concentrations ranging from 10.0 to 60.0 microg ml(-1) in ethanol 99.5%. Second-derivative provided to be unsuitable for interval evaluation obtaining unacceptable accuracy. Analytical method was validated for first-derivative, according to the experimental results: correlation coefficient (r = 0.9999); specificity to total flavonoids quantification, expressed in rutin, at wavelength 388.0 nm and selectivity with elimination of interference from matrix; Rc = 108.78%; intra- and inter-run precision (1.30-3.65% and 3.48-4.68%), and intra- and inter-run accuracy (100.00-112.19% and 101.25-118.44%); LOD = 0.62 microg ml(-1) and LOQ = 1.86 microg ml(-1).