Maria Valéria Robles Velasco

Broad spectrum bioactive sunscreens

The development of sunscreens containing reduced concentration of chemical UV filters, even though, possessing broad spectrum effectiveness with the use of natural raw materials that improve and infer UV absorption is of great interest. Due to the structural similarities between polyphenolic compounds and organic UV filters, they might exert photoprotection activity. The objective of the present research work was to develop bioactive sunscreen delivery systems containing rutin, Passiflora incarnata L. and Plantago lanceolata extracts associated or not with organic and inorganic UV filters. UV transmission of the sunscreen delivery system films was performed by using diffuse transmittance measurements coupling to an integrating sphere. In vitro photoprotection efficacy was evaluated according to the following parameters: estimated sun protection factor (SPF); Boots Star Rating category; UVA/UVB ratio; and critical wavelength (lambda(c)). Sunscreen delivery systems obtained SPF values ranging from 0.972+/-0.004 to 28.064+/-2.429 and bioactive compounds interacted with the UV filters positive and negatively. This behavior may be attributed to: the composition of the delivery system; the presence of inorganic UV filter and quantitative composition of the organic UV filters; and the phytochemical composition of the P. incarnata L. and P. lanceolata extracts. Among all associations of bioactive compounds and UV filters, we found that the broad spectrum sunscreen was accomplished when 1.68% (w/w) P. incarnata L. dry extract was in the presence of 7.0% (w/w) ethylhexyl methoxycinnamate, 2.0% (w/w) benzophenone-3 and 2.0% (w/w) TiO(2). It was demonstrated that this association generated estimated SPF of 20.072+/-0.906 and it has improved the protective defense against UVA radiation accompanying augmentation of the UVA/UVB ratio from 0.49 to 0.52 and lambda(c) from 364 to 368.6nm.

Hair fiber characteristics and methods to evaluate hair physical and mechanical properties

O cabelo e uma fibra natural formada por queratina, uma proteina composta por teor elevado de enxofre proveniente da cistina. As propriedades principais do cabelo dependem de sua geometria, estrutura fisica. Caracteristicas fisicas e mecânicas das fibras capilares envolvem propriedades que melhoram: elasticidade, maciez, volume, maleabilidade, facilidade para o ato de pentear e brilho. A avaliacao de tais propriedades do cabelo pode ser obtida por metodos diversos, como: microscopia optica e eletronica, mensuracao da resistencia mecânica, determinacao do brilho e tomografia por coerencia optica (OCT).

Proteção à radiação ultravioleta: recursos disponíveis na atualidade em fotoproteção

Ultraviolet radiation can damage the DNA, cause immunosuppression, chemical and histological alterations in the epidermis, early photoaging, cataracts and carcinogenesis, among others. Photoprotection prevents these and other harmful effects of ultraviolet radiation. Sunscreens, protective clothing, proper accessories and safe sun exposure are essential photoprotection tools. The main forms of photoprotection are presented and discussed in this article, including sunscreens containing organic and inorganic filters, the assessment of their efficacy and current developments on the topic.

Relaxing/straightening of Afro-ethnic hair: historical overview

Afro‐ethnic hair, when compared with naturally straight hair, presents some important variations such as differences in diameter in many points of the thread, ellipsoidal threads, and low trend of hydrating the scalp thus turning the hair drier, because the natural sebum distribution is irregular along the thread. This kind of hair may be straightened through both chemical and thermal methods. Straightening is a chemical process by which excessively curly hair is straightened in an irreversible way. Generally, the products used are formulated in a cosmetic emulsion with high pH. In this review, we present the historical development of hair straightening or relaxing through the evolution of the product categories.

Effects of caffeine and siloxanetriol alginate caffeine, as anticellulite agents, on fatty tissue: histological evaluation

Background  Cellulite is a physiological condition that presents etiologic plurality. Caffeine and its derivatives are used in anticellulite cosmetics due to their lipolytic activity on fatty cells. Siloxanetriol alginate caffeine (SAC) is a silanol derived from organic silicon. Radicals primarily from SAC are caffeine and the mannuronic acid.

Cutaneous biocompatible rutin-loaded gelatin-based nanoparticles increase the SPF of the association of UVA and UVB filters

The encapsulation of natural ingredients, such as rutin, can offer improvements in sun protection effectiveness. This strategy can provide enhanced flavonoid content and produces an improved bioactive compound with new physical and functional characteristics. As an alternative to common synthetic-based sunscreens, rutin-entrapped gelatin nanoparticles (GNPs) were designed and associated with ethylhexyl dimethyl PABA (EHDP), ethylhexyl methoxycinnamate (EHMC) and methoxydibenzoylmethane (BMDBM) in sunscreen formulations. The purpose of this study was to develop rutin-loaded gelatin nanoparticles and characterize their physicochemical, thermal, functional and safety properties. Rutin-loaded gelatin nanoparticles increased antioxidant activity by 74% relative to free-rutin (FR) solution. Also, this new ingredient upgraded the Sun Protection Factor (SPF) by 48%, indicating its potential as a raw material for bioactive sunscreens. The safety profile indicated that GNPs and glutaraldehyde (GTA) decreased HaCaT cell viability in a concentration/time-dependent manner. However, both blank nanoparticles (B-NC) and rutin-loaded nanoparticles (R-NC) had good performance on skin compatibility tests. These results functionally characterized rutin-loaded nanoparticles as a safe SPF enhancer in sunscreens, especially in association with UV filters.

Estabilidade e estudo de penetração cutânea in vitro da rutina veiculada em uma emulsão cosmética através de um modelo de biomembrana alternativo

Rutin is employed as antioxidant and to prevent the capillary fragility and, when incorporated in cosmetic emulsions, it must target the action site. In vitro cutaneous penetration studies through human skin is the ideal situation, however, there are difficulties to obtain and to maintain this tissue viability. Among the membrane models, shed snake skin presents itself as pure stratum corneum, providing barrier function similar to human and it is obtained without the animal sacrifice. The objectives of this research were the development and stability evaluation of a cosmetic emulsion containing rutin and propylene glycol (penetration enhancer) and the evaluation of rutin in vitro cutaneous penetration and retention from the emulsion, employing an alternative model biomembrane. Emulsion was developed with rutin and propylene glycol, both at 5.0% w/w. Active substance presented on the formulation was quantified by a validated spectrophotometric method at 361.0 nm. Rutin cutaneous penetration and retention was performed in vertical diffusion cells with shed snake skin of Crotalus durissus, as alternative model biomembrane, and distilled water and ethanol 99.5% (1:1), as receptor fluid. The experiment was conducted for six hours, at 37.0 ± 0.5 oC with constant stirring of 300 rpm. Spectrophotometry at 410.0 nm, previously validated, determined the active substance after cutaneous penetration/retention. Emulsion did not promote rutin cutaneous penetration through C. durissus skin, retaining 0.931 ± 0.0391 mg rutin/mg shed snake skin. The referred formulation was chemically stable for 30 days after stored at 25.0 ± 2.0 oC, 5.0 ± 0.5 oC and 45.0 ± 0.5 oC. In conclusion, it has not been verified the active cutaneous penetration through the model biomembrane, but only its retention on the Crotalus durissus stratum corneum, condition considered stable for 30 days.

Validation of HPLC stability-indicating method for Vitamin C in semisolid pharmaceutical/cosmetic preparations with glutathione and sodium metabisulfite, as antioxidants.

HPLC stability-indicating method was validated for Vitamin C (ascorbic acid) in semisolid pharmaceutical/cosmetic formulations containing glutathione and sodium metabisulfite, as antioxidants. The described procedure included a reliable, precise, accurate and specific method determination employing a 250mm x 4.6mm C(18) column, 0.2% metaphosphoric acid/methanol/acetonitrile (90:8:2, v/v/v) as the mobile phase and detection at 254nm. Nicotinic and ascorbic acids were employed as standards, both presenting purity of 99.0%. Linearity was established for the ascorbic acid concentrations ranging form 1.0 to 12microg mL(-1), accuracy/recovery percentage was 95.46-101.54%, precision values were 0.38 (intra-day) and 1.22% (inter-days), and LOD and LOQ were found to be 0.05 and 0.17microg mL(-1), respectively. The working mobile phase elevated the ascorbic acid retention time to approximately 3.5min at a flow rate of 1.0mL min(-1) and provided resolution of the active from the nicotinic acid (internal standard), degradation product (oxalic acid) and other excipients from the pharmaceutical/cosmetic preparations.

Accelerated chemical stability data of O/W fluid emulsions containing the extract of Trichilia catigua Adr. Juss (and) Ptychopetalum olacoides Bentham

O desenvolvimento de formas farmaceuticas topicas necessita ensaios fisicos, fisico-quimicos e quimicos que selecionem rapidamente a formulacao de melhor desempenho de estabilidade. Este estudo avaliou a estabilidade de emulsoes O/A fluidas, por meio da determinacao de flavonoides totais, expressos em rutina, contendo o extrato padronizado de Trichilia catigua Adr. Juss (e) Ptychopetalum olacoides Bentham. As amostras foram armazenadas a 24,0 ± 2,0 oC; 5,0 ± 0,5 oC e 40,0 ± 0,5 oC durante 90 dias e foram avaliadas segundo o protocolo para a determinacao da estabilidade acelerada, conhecida como Teste de Estabilidade Normal. A quantificacao da substância ativa foi determinada por espectrofotometria na regiao do ultravioleta a 361,0 nm, previamente validado. Apos os ensaios de estabilidade, as emulsoes O/A fluidas apresentaram estabilidade adequada, pelo menos, no periodo de 90 dias, quando armazenadas a 24,0 ± 2,0 oC e 5,0 ± 0,5 oC. A condicao de armazenamento a 40,0 ± 0,5 oC acelerou a cinetica de degradacao dos flavonoides totais, expressos em rutina, portanto, preparacoes possuindo esta categoria de substância ativa natural ou formulacoes similares nao devem ser armazenadas em temperaturas elevadas.

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.