RESUMO
BACKGROUND: There is currently a great interest not only in developing products for the protection and recovery of chemically damaged hair, but also in developing effective protocols to investigate the impact of chemical treatments and attest the efficacy of innovative hair care products. Among the most relevant cosmetic treatments for hair are bleaching and coloring, which have been shown to significantly impair mechanical and structural properties. OBJECTIVES: This study aimed to characterize the damage induced by hair bleaching and coloring and to evaluate the protective effects of a hair care treatment based on integral silk proteins (fibroin and sericin) and vegetable-derived polysaccharides from linseed (Linum usitatissimum L.). METHODS: Hair swatches were subjected to different treatment protocols in order to evaluate the protective effect of proposed and benchmark products during bleaching and coloring processes. Tensile tests were performed to assess mechanical properties and improvement in resistance to breakage. Goniophotometric measurements were applied to determine improvement in luster. Hair fiber surface and relief were evaluated by SEM image analysis. RESULTS: Swatches bleached and treated with both evaluated products had a significant increase in resistance and reduced structural damage. Swatches colored and treated with both evaluated products showed reduced structural damage, and a significant increase in resistance and luster after the 1st and 5th washes. CONCLUSIONS: The proposed product was effective in protecting and repairing bleached and colored swatches, improving resistance and luster and reducing structural damage. By applying complementary techniques within a reliable evaluation protocol, it was possible to attest the protective properties of the product under study.
Assuntos
Cosméticos , Preparações para Cabelo , Cabelo , Humanos , Polissacarídeos/uso terapêutico , ProteínasRESUMO
Chemically stable ester derivatives of vitamins A, C and E have become a focus of interest for their role in the satisfactory results in skin aging treatments. Accordingly, the aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing 1% retinyl palmitate, ascorbyl tetraisopalmitate and tocopheryl acetate, alone or in combination. In the studies of physical stability, a Brookfield rheometer was used to determine rheological behavior of formulations containing the vitamins. Chemical stability was determined by HPLC on a Shimadzu system with UV detection. Results showed that formulations had pseudoplastic behavior and that vitamins did not alter their apparent viscosity and thixotropy. In the chemical stability studies, first-order reaction equations were used for determinations of the shelf-life of vitamins derivatives considering a remaining concentration of 85%. Combined vitamins in a single formulation had a slightly lower degradation rate as compared to different preparations containing only one of the vitamins. Considering that many cosmetic formulations contain vitamin combinations it is suggested that the present study may contribute to the development of more stable formulations containing liposoluble vitamins.
Assuntos
Ácido Ascórbico/análogos & derivados , Cosméticos/química , Vitamina A/análogos & derivados , Vitamina E/análogos & derivados , Ácido Ascórbico/química , Química Farmacêutica/métodos , Diterpenos , Estabilidade de Medicamentos , Ésteres de Retinil , Vitamina A/química , Vitamina E/químicaRESUMO
BACKGROUND: It is well known that the Amazon region presents a huge biodiversity; therefore, countless natural resources are being employed in the production of phytocosmetics and phytomedicines. OBJECTIVE: The purpose of this work was to obtain emulsions produced with Buriti oil and non-ionic surfactants. METHODS: Two surfactant systems were employed (Steareth-2 associated to Ceteareth-5 and to Ceteareth-20) to produce the emulsions using phase diagram method. Emulsions were obtained by echo-planar imaging method at 75°C. Rheological behavior and zeta potential were evaluated, and accelerated stability tests were performed. RESULTS: All emulsions analyzed presented pseudoplastic behavior. Zeta potential values were obtained between -14.2 and -53.3 mV. The formulations did not show changes in either physical stability, pH, or rheological behavior after accelerated stability tests. Significant differences were observed only after temperature cycling test. CONCLUSION: Based on these results, the emulsions obtained could be considered as promising delivery systems.