The Experts below are selected from a list of 24039 Experts worldwide ranked by ideXlab platform
Saurabh Mani Tripathi - One of the best experts on this subject based on the ideXlab platform.
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Critical Wavelength in the Transmission Spectrum of a Directional Coupler Employing GeO 2 -doped Single Mode Fibers.
arXiv: Optics, 2017Co-Authors: Garima Bawa, Saurabh Mani TripathiAbstract:We examine the existence of Critical Wavelength in transmission spectrum of a Directional Coupler, employing GeO 2 doped SMF and show that it differs significantly from that observed in SMS structures. Origin of Critical-Wavelength is also explained.
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Critical Wavelength in the transmission spectrum of a directional coupler employing geo 2 doped single mode fibers
arXiv: Optics, 2017Co-Authors: Garima Bawa, Saurabh Mani TripathiAbstract:We examined the existence of Critical Wavelength in transmission-spectrum of a Directional Coupler, employing GeO 2 - doped SMF and showed that it differs significantly from that observed in SMS structures. The origin of Critical Wavelength is explained. The sensitivity has been observed to be maximum for the transmission maximum or minimum nearest to the Critical Wavelength. The existence of a Wavelength below the Critical Wavelength called the cross-over Wavelength where the spectrum again changes its nature of spectral shift has also been observed. The effect of increase of core radius and of seperations between cores of the two fibers; and the change in GeO 2 doping concentration inside core on Critical Wavelength has also been studied. It was observed that there exist two Critical Wavelengths for a Directional Coupler consisting of a fiber having B 2 O 3 doping along with GeO 2 while the other has only GeO 2 doping. The effect of temperature and strain on the transmission spectrum of the Directional Coupler has been studied.
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Critical Wavelength in the transmission spectrum of sms fiber structure employing geo _ 2 doped multimode fiber
IEEE Photonics Technology Letters, 2010Co-Authors: Saurabh Mani Tripathi, Arun Kumar, Emmanuel Marin, J P MeunierAbstract:We demonstrate and explain the existence of a Critical Wavelength in the transmission spectrum of single-multi-singlemode fiber structures, employing GeO2-doped multimode fibers (MMFs), such that the spectrum shows opposite spectral shift on either side of this Wavelength with increasing temperature. Further, the shift is maximum for peaks/dips nearest to this Wavelength. The variation of Critical Wavelength with temperature is also measured. A theoretical account of the observed behavior has been presented and the results are found to be in excellent agreement with the experiments. It is shown theoretically that for a given MMF there should be two Critical Wavelengths of the opposite nature separated by a large Wavelength difference.
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Critical Wavelength in sms structures employing geo2 doped mmf
Frontiers in Optics, 2009Co-Authors: Saurabh Mani Tripathi, Arun Kumar, Emmanuel Marin, Jeanpierre MeunierAbstract:We demonstrate experimentally and explain theoretically that SMS structures employing GeO2doped multimode fibers are most sensitive near a Critical Wavelength and show opposite spectral shift around it with respect to change in ambient temperature.
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strain and temperature sensing characteristics of single mode multimode single mode structures
Journal of Lightwave Technology, 2009Co-Authors: Saurabh Mani Tripathi, Arun Kumar, R K Varshney, Y B P Kumar, Emmanuel Marin, J P MeunierAbstract:We present a comprehensive study of the strain and temperature-sensing characteristics of single-mode-multimode-single-mode (SMS) structures based on the modal interference of guided modes of graded index multimode fiber (MMF) section spliced in between two single-mode fibers. A detailed theoretical study of the structures in terms of the refractive index distribution, effect of dopant and their concentrations, and the variation of core diameter has been carried out. Our study shows that for the SMS structure with a GeO2-doped MMF there exists a Critical Wavelength on either side of which the spectrum shows opposite spectral shift with a change in temperature/strain, whereas for structures with a P2O5-doped MMF it shows monotonic red shift with increasing temperature/strain. It has been found that the Critical Wavelength shifts toward higher Wavelengths with decreasing ldquoqrdquo value/doping concentration. Using different MMFs, both the red and blue spectral shifts have been observed experimentally. It has also been found that the SMS structure has higher sensitivity toward this Critical Wavelength. The study should find application in designing strain-insensitive high-sensitive temperature sensors or vice versa.
Xiaopeng Dong - One of the best experts on this subject based on the ideXlab platform.
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studies on temperature and strain sensitivities of a few mode Critical Wavelength fiber optic sensor
IEEE Sensors Journal, 2019Co-Authors: Xiaopeng Dong, Tong Sun, K T V GrattanAbstract:This paper studied the relationship between the temperature/strain Wavelength sensitivity of a fiber optic in-line Mach–Zehnder interferometer (MZI) sensor and the Wavelength separation of the measured Wavelength to the Critical Wavelength (CWL) in a CWL-existed interference spectrum formed by interference between LP01 and LP02 modes. The in-line MZI fiber optic sensor has been constructed by splicing a section of specially designed few-mode fiber (FMF), which supports LP01 and LP02 modes propagating in the fiber, between two pieces of single-mode fiber. The propagation constant difference, $\Delta \beta $ , between the LP01 and LP02 modes, changes non-monotonously with Wavelength and reaches a maximum at the CWL. As a result, in the sensor operation, peaks on the different sides of the CWL then shift in opposite directions, and the associated temperature/strain sensitivities increase significantly when the measured Wavelength points become close to the CWL, from both sides of the CWL. A theoretical analysis carried out has predicted that with this specified FMF sensor approach, the temperature/strain Wavelength sensitivities are governed by the Wavelength difference between the measured Wavelength and the CWL. This conclusion was seen to agree well with the experimental results obtained. Combining the Wavelength shifts of the peaks and the CWL in the transmission spectrum of the SFS structure, this paper has shown that this approach forms the basis of effective designs of high sensitivity sensors for multi-parameter detection and offering a large measurement range to satisfy the requirements needed for better industrial measurements.
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progress of optical fiber sensors based on the special two mode fiber with Critical Wavelength
Opto-Electronics and Communications Conference, 2018Co-Authors: Xiaopeng Dong, Su Juan, Yunqing GuanAbstract:Progress of fiber sensors including temperature, strain, bending, index, and humidity sensors, etc., based on mode interference in a special two-mode fiber with Critical Wavelength. The novel method is superior to conventional Wavelength detection method.
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detection of refractive index change from the Critical Wavelength of an etched few mode fiber
Journal of Lightwave Technology, 2017Co-Authors: Xiaopeng DongAbstract:A novel scheme for the detection of refractive index change based on the mode interference in a special few mode fiber (FMF) is proposed in this paper. The parameters and index profile of the FMF used in the measurement are specifically designed so that only LP01 and LP02 modes are transmitted within the operation Wavelength, and the propagation constant difference Δβ between these two modes reaches maximum at Critical Wavelength (CWL). An inline Mach–Zehnder interferometric sensor for the detection of surrounding refractive index (SRI) is constructed by splicing FMF with two sections of conventional single mode fiber. We demonstrated at the first time that the CWL will change monotonically with the change of SRI in the measurement range of 1.316–1.439. The experimental sensitivity of the CWL increases with the increase of SRI. A sensitiviy of 140.626 ± 12.560 nm/RIU in the range of 1.316–1.383 and a maximum sensitivity of 2489.796 ± 190.179 nm/RIU in the range of 1.433–1.439 were obtained, respectively, in the experiment. At present parameters of the etched FMF, the limit of detection of the refractive index is 3.413 × 10–4 RIU in the SRI range of 1.316–1.383, and 1.928 × 10–5 RIU in the SRI range of 1.433–1.439, respectively. The detection of SRI via monitoring the shift of CWL is superior to the traditional detection method via monitoring merely the shift of peak or dip Wavelength of the transmission spectrum, since the latter usually suffers from limited measurement range and multivalue problem because it is difficult to identify and follow one specific peak or dip from the transmission spectrum especially if the system needs to reset in practical application. The novel detection scheme based on monitoring the shift of the exclusive CWL of FMF is promising in practical applications.
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property of bent few mode fiber and its application in displacement sensor
IEEE Photonics Technology Letters, 2016Co-Authors: Xiaopeng DongAbstract:The intermodal interference between LP01 and LP02 modes of few mode fiber (FMF) under bending is studied theoretically and experimentally. The shift of Critical Wavelength caused by fiber curvature is measured in the experiment and analyzed theoretically for the first time. The sensitivity of the Critical Wavelength shift to curvature variation has been obtained from the measurement and calculation results. Based on the Wavelength shift effect induced by the curvature of FMF, a novel displacement sensor employing a helix coil, as an example of the application, is proposed in this letter. With present fiber and structure parameters, 120-mm displacement with 0.172-nm/mm maximum sensitivity has been achieved by changing the fiber curvature through adjusting the pitch of the helix coil. The effect of curvature-induced Wavelength shift provides various potential applications of FMF such as displacement and curvature sensors.
Cefali, Leticia Caramori - One of the best experts on this subject based on the ideXlab platform.
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In vitro SPF and photostability assays of emulsion containing nanoparticles with vegetable extracts rich in flavonoids
Estados Unidos, 2020Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Eberlin Samara, Gonçalves, Fernanda Cristina Da Silva, Fernandes, Ana Rita, Marto Joana, Ribeiro, Helena Margarida, Foglio, Mary Ann, Mazzola, Priscila Gava, Souto, Eliana BarbosaAbstract:The aim of study was to determine the in vitro sun protection factor (SPF) and the photostability profile of a topical formulation composed of nanoparticles loaded with vegetable extracts and to assess its physicochemical properties. Chitosan/tripolyphosphate (TPP) nanoparticles loaded with flavonoids-enriched vegetable extracts (Ginkgo biloba L., Dimorphandra mollis Benth, Ruta graveolens, and Vitis vinifera L.) were produced and characterized for their morphology, mean particle size, zeta potential, and encapsulation efficiency. A final topical formulation was obtained by dispersing chitosan/TPP nanoparticles in an o/w emulsion. Results showed that nanoparticles dispersion exhibited yellowish color, spherical shape, and uniform appearance. Extract-loaded chitosan/TPP nanoparticles showed a mean particle size of 557.11 +/- 3.1nm, polydispersity index of 0.39 +/- 0.27, zeta potential of +11.54 +/- 2.1mV, and encapsulation efficiency of 75.89% of rutin. The recorded texture parameters confirm that the developed formulation is appropriate for skin application. The SPF obtained was 2.3 +/- 0.4, with a Critical Wavelength of 387.0nm and 0.69 UVA/UVB ratio. The developed formulation exhibited photostability, allowing the release of flavonoids from nanoparticles while retaining rutin into the skin in a higher extension201CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São PauloSem informaçãoSem informação2015/25533-7; 2017/14757-
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Flavonoid ‐ enriched plant ‐ extract ‐ loaded emulsion : a novel phytocosmetic sunscreen formulation with antioxidant properties. antioxidants
'MDPI AG', 2020Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Eberlin Samara, Fernandes, Ana Rita, Ilza Maria De ,oliveira Sousa, Da Silva Gonçalves, Fernanda Cristina, Dávila, José Luis, Jozala, Angela Faustino, Chaud, Marco Vinicius, Sánchez-lópez E.Abstract:The aim of this study was to develop a phytocosmetic sunscreen emulsion with antioxidant effect, containing a blend of flavonoid-enriched plant extracts. In vitro sun protection factor, antioxidant activity, skin irritation, photostability, cutaneous permeation, and retention of flavonoids were evaluated. Thermodynamically stable emulsions were obtained and tested for sensorial analysis after loading the blend of extracts. The selected emulsion was stable when stored at low temperatures (5 °C), for which after 120 days the concentration of quercetin and rutin were above their limit of quantification, i.e., 2.8 ± 0.39 μg/mL and 30.39 ± 0.39 μg/mL, respectively. Spreadability, low rupture strength and adhesiveness were shown to be similar to a conventional topical product. Higher brittleness, pseudo-plastic, and viscoelastic behaviors were also recorded for the developed phytocosmetic sunscreen. The product presented a Critical Wavelength of 387.0 nm and ultraviolet rays A and B (UVA/UVB) rate of 0.78, confirming that the developed formulation shows capacity for UVA/UVB protection, protecting skin against damages caused by ultraviolet (UV) radiation. Rutin was shown to permeate the skin barrier and was also quantified in the stratum corneum (3.27 ± 1.92 μg/mL) by tape stripping and retention test (114.68 ± 8.70 μg/mL). The developed flavonoid-enriched phytocosmetic was shown to be non-irritant to skin by an in vitro assay. Our results confirm the antioxidant activity, sun protection, and physical properties of the developed phytocosmetic for topical applicatio
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Evaluation of in vitro solar protection factor (spf), antioxidant activity, and cell viability of mixed vegetable extracts from dirmophandra mollis benth, ginkgo biloba l., ruta graveolens l., and vitis vinifera l.
Suíça, 2020Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Fernandes, Ana Rita, Foglio, Mary Ann, Mazzola, Priscila Gava, Sousa, Ilza Maria De Oliveira, Sanchez-lopez Elena, Figueiredo, Mariana Cecchetto, Ruiz, Ana Lucia Tasca Gois, Souto, Eliana BarbosaAbstract:The aim of this study was to validate a HPLC method for the assay of flavonoids in extracts obtained from natural sources, i.e., from Dirmophandra mollis Benth, Ginkgo biloba L., Ruta graveolens L., and Vitis vinifera L. The potential sun protecting effect, antioxidant activity, and cell viability of the extracts were also determined. Individual extracts (obtained from each individual species) and a mixed extract (containing the four extracts) were analyzed by the validated HPLC method for the identification of flavonoids and quantification of rutin and quercetin. An in vitro cell viability study was carried out using the neutral red method. The in vitro sun protection factor was determined by spectral transmittance and in vitro antioxidant efficacy was evaluated against DPPH, ABTS, and AAPH radicals. The HPLC method used for the identification and quantification of flavonoids in extracts exhibited linearity, precision, accuracy, and robustness. Detection and quantification limits were, respectively, 2.881 +/- 0.9 mu g.mL(-1) and 0.864 +/- 0.9 mu g.mL(-1) for quercetin, and 30.09 +/- 1 mu g.mL(-1) and 9.027 +/- 1.1 mu g.mL(-1) for rutin. All extracts did not affect cell viability at the evaluated concentration range and exhibited a sun protection effect and antioxidant activity. Among the evaluated extracts, Ginkgo biloba L. and the mixed extract depicted the most expressive antioxidant activity. The mixed extract exhibited sunscreen protection against ultraviolet A (UVA) and ultraviolet B (UVB) and a Critical Wavelength of 372.7 +/- 0.1. Our results translate the enhanced flavonoids' composition of the mixed extract, which may be a potential alternative over sunscreens and antioxidants in pharmaceutic/cosmetic formulations811CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São PauloSem informaçãoSem informação2015/25533-7; 2017/14757-
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In vitro SPF and photostability assays of emulsion containing nanoparticles with vegetable extracts rich in flavonoids
American Association of Pharmaceutical Scientists, 2019Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Eberlin Samara, Gonçalves, Fernanda Cristina Da Silva, Fernandes, Ana Rita, Marto Joana, Ribeiro, Helena Margarida, Foglio, Mary Ann, Mazzola, Priscila Gava, Souto, Eliana BarbosaAbstract:The aim of study was to determine the in vitro sun protection factor (SPF) and the photostability profile of a topical formulation composed of nanoparticles loaded with vegetable extracts and to assess its physicochemical properties. Chitosan/tripolyphosphate (TPP) nanoparticles loaded with flavonoids-enriched vegetable extracts (Ginkgo biloba L., Dimorphandra mollis Benth, Ruta graveolens, and Vitis vinifera L.) were produced and characterized for their morphology, mean particle size, zeta potential, and encapsulation efficiency. A final topical formulation was obtained by dispersing chitosan/TPP nanoparticles in an o/w emulsion. Results showed that nanoparticles dispersion exhibited yellowish color, spherical shape, and uniform appearance. Extract-loaded chitosan/TPP nanoparticles showed a mean particle size of 557.11±3.1 nm, polydispersity index of 0.39±0.27, zeta potential of +11.54±2.1 mV, and encapsulation efficiency of 75.89% of rutin. The recorded texture parameters confirm that the developed formulation is appropriate for skin application. The SPF obtained was 2.3±0.4, with a Critical Wavelength of 387.0 nm and 0.69 UVA/UVB ratio. The developed formulation exhibited photostability, allowing the release of flavonoids from nanoparticles while retaining rutin into the skin in a higher extension.The authors acknowledge FAPESP (grant number 2015/25533-7 and 2017/14757-7), CAPES, and CNPq agencies for the financial support of this study. The authors also acknowledge the financial support received from the Portuguese Science and Technology Foundation (FCT/MCT) and from the European Funds (PRODER/COMPETE) under the project reference M-ERA-NET/0004/2015-PAIRED, co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio
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Flavonoid-enriched plant-extract-loaded emulsion: a novel phytocosmetic sunscreen formulation with antioxidant properties
'MDPI AG', 2019Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Eberlin Samara, Gonçalves, Fernanda Cristina Da Silva, Fernandes, Ana Rita, Dávila, José Luis, Jozala, Angela Faustino, Chaud, Marco Vinicius, Sousa, Ilza Maria De Oliveira, Sanchez-lopez ElenaAbstract:The aim of this study was to develop a phytocosmetic sunscreen emulsion with antioxidant effect, containing a blend of flavonoid-enriched plant extracts. In vitro sun protection factor, antioxidant activity, skin irritation, photostability, cutaneous permeation, and retention of flavonoids were evaluated. Thermodynamically stable emulsions were obtained and tested for sensorial analysis after loading the blend of extracts. The selected emulsion was stable when stored at low temperatures (5 C), for which after 120 days the concentration of quercetin and rutin were above their limit of quantification, i.e., 2.8 ± 0.39 µg/mL and 30.39 ± 0.39 µg/mL, respectively. Spreadability, low rupture strength and adhesiveness were shown to be similar to a conventional topical product. Higher brittleness, pseudo-plastic, and viscoelastic behaviors were also recorded for the developed phytocosmetic sunscreen. The product presented a Critical Wavelength of 387.0 nm and ultraviolet rays A and B (UVA/UVB) rate of 0.78, confirming that the developed formulation shows capacity for UVA/UVB protection, protecting skin against damages caused by Ultraviolet (UV) radiation. Rutin was shown to permeate the skin barrier and was also quantified in the stratum corneum (3.27 ± 1.92 µg/mL) by tape stripping and retention test (114.68 ± 8.70 µg/mL). The developed flavonoid-enriched phytocosmetic was shown to be non-irritant to skin by an in vitro assay. Our results confirm the antioxidant activity, sun protection, and physical properties of the developed phytocosmetic for topical application.This research was funded by FAPESP (grant number 2015/25533‐7 and 2017/14757‐7), CAPES and CNPq. The authors also received support from the Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) under the project reference M‐ERA‐NET/0004/2015‐PAIRED, co‐financed by FEDER, under the Partnership Agreement PT2020, and PhD scholarship (SFRH/BD/130555/2017).info:eu-repo/semantics/publishedVersio
J P Meunier - One of the best experts on this subject based on the ideXlab platform.
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Critical Wavelength in the transmission spectrum of sms fiber structure employing geo _ 2 doped multimode fiber
IEEE Photonics Technology Letters, 2010Co-Authors: Saurabh Mani Tripathi, Arun Kumar, Emmanuel Marin, J P MeunierAbstract:We demonstrate and explain the existence of a Critical Wavelength in the transmission spectrum of single-multi-singlemode fiber structures, employing GeO2-doped multimode fibers (MMFs), such that the spectrum shows opposite spectral shift on either side of this Wavelength with increasing temperature. Further, the shift is maximum for peaks/dips nearest to this Wavelength. The variation of Critical Wavelength with temperature is also measured. A theoretical account of the observed behavior has been presented and the results are found to be in excellent agreement with the experiments. It is shown theoretically that for a given MMF there should be two Critical Wavelengths of the opposite nature separated by a large Wavelength difference.
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strain and temperature sensing characteristics of single mode multimode single mode structures
Journal of Lightwave Technology, 2009Co-Authors: Saurabh Mani Tripathi, Arun Kumar, R K Varshney, Y B P Kumar, Emmanuel Marin, J P MeunierAbstract:We present a comprehensive study of the strain and temperature-sensing characteristics of single-mode-multimode-single-mode (SMS) structures based on the modal interference of guided modes of graded index multimode fiber (MMF) section spliced in between two single-mode fibers. A detailed theoretical study of the structures in terms of the refractive index distribution, effect of dopant and their concentrations, and the variation of core diameter has been carried out. Our study shows that for the SMS structure with a GeO2-doped MMF there exists a Critical Wavelength on either side of which the spectrum shows opposite spectral shift with a change in temperature/strain, whereas for structures with a P2O5-doped MMF it shows monotonic red shift with increasing temperature/strain. It has been found that the Critical Wavelength shifts toward higher Wavelengths with decreasing ldquoqrdquo value/doping concentration. Using different MMFs, both the red and blue spectral shifts have been observed experimentally. It has also been found that the SMS structure has higher sensitivity toward this Critical Wavelength. The study should find application in designing strain-insensitive high-sensitive temperature sensors or vice versa.
Ataide, Janaina Artem - One of the best experts on this subject based on the ideXlab platform.
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In vitro SPF and photostability assays of emulsion containing nanoparticles with vegetable extracts rich in flavonoids
Estados Unidos, 2020Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Eberlin Samara, Gonçalves, Fernanda Cristina Da Silva, Fernandes, Ana Rita, Marto Joana, Ribeiro, Helena Margarida, Foglio, Mary Ann, Mazzola, Priscila Gava, Souto, Eliana BarbosaAbstract:The aim of study was to determine the in vitro sun protection factor (SPF) and the photostability profile of a topical formulation composed of nanoparticles loaded with vegetable extracts and to assess its physicochemical properties. Chitosan/tripolyphosphate (TPP) nanoparticles loaded with flavonoids-enriched vegetable extracts (Ginkgo biloba L., Dimorphandra mollis Benth, Ruta graveolens, and Vitis vinifera L.) were produced and characterized for their morphology, mean particle size, zeta potential, and encapsulation efficiency. A final topical formulation was obtained by dispersing chitosan/TPP nanoparticles in an o/w emulsion. Results showed that nanoparticles dispersion exhibited yellowish color, spherical shape, and uniform appearance. Extract-loaded chitosan/TPP nanoparticles showed a mean particle size of 557.11 +/- 3.1nm, polydispersity index of 0.39 +/- 0.27, zeta potential of +11.54 +/- 2.1mV, and encapsulation efficiency of 75.89% of rutin. The recorded texture parameters confirm that the developed formulation is appropriate for skin application. The SPF obtained was 2.3 +/- 0.4, with a Critical Wavelength of 387.0nm and 0.69 UVA/UVB ratio. The developed formulation exhibited photostability, allowing the release of flavonoids from nanoparticles while retaining rutin into the skin in a higher extension201CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São PauloSem informaçãoSem informação2015/25533-7; 2017/14757-
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Flavonoid ‐ enriched plant ‐ extract ‐ loaded emulsion : a novel phytocosmetic sunscreen formulation with antioxidant properties. antioxidants
'MDPI AG', 2020Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Eberlin Samara, Fernandes, Ana Rita, Ilza Maria De ,oliveira Sousa, Da Silva Gonçalves, Fernanda Cristina, Dávila, José Luis, Jozala, Angela Faustino, Chaud, Marco Vinicius, Sánchez-lópez E.Abstract:The aim of this study was to develop a phytocosmetic sunscreen emulsion with antioxidant effect, containing a blend of flavonoid-enriched plant extracts. In vitro sun protection factor, antioxidant activity, skin irritation, photostability, cutaneous permeation, and retention of flavonoids were evaluated. Thermodynamically stable emulsions were obtained and tested for sensorial analysis after loading the blend of extracts. The selected emulsion was stable when stored at low temperatures (5 °C), for which after 120 days the concentration of quercetin and rutin were above their limit of quantification, i.e., 2.8 ± 0.39 μg/mL and 30.39 ± 0.39 μg/mL, respectively. Spreadability, low rupture strength and adhesiveness were shown to be similar to a conventional topical product. Higher brittleness, pseudo-plastic, and viscoelastic behaviors were also recorded for the developed phytocosmetic sunscreen. The product presented a Critical Wavelength of 387.0 nm and ultraviolet rays A and B (UVA/UVB) rate of 0.78, confirming that the developed formulation shows capacity for UVA/UVB protection, protecting skin against damages caused by ultraviolet (UV) radiation. Rutin was shown to permeate the skin barrier and was also quantified in the stratum corneum (3.27 ± 1.92 μg/mL) by tape stripping and retention test (114.68 ± 8.70 μg/mL). The developed flavonoid-enriched phytocosmetic was shown to be non-irritant to skin by an in vitro assay. Our results confirm the antioxidant activity, sun protection, and physical properties of the developed phytocosmetic for topical applicatio
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Flavonoid-enriched plant-extract-loaded emulsion: a novel phytocosmetic sunscreen formulation with antioxidant properties
Suíça, 2020Co-Authors: Cefali, Leticia Caramor, Ataide, Janaina Artem, Eberlin Samara, Gonçalves, Fernanda Cristina Da Silva, Fernandes, Ana Rita, Dávila, José Luis, Jozala, Angela Faustino, Chaud, Marco Vinicius, Sousa, Ilza Maria De Oliveira, Sanchez-lopez ElenaAbstract:The aim of this study was to develop a phytocosmetic sunscreen emulsion with antioxidant effect, containing a blend of flavonoid-enriched plant extracts. In vitro sun protection factor, antioxidant activity, skin irritation, photostability, cutaneous permeation, and retention of flavonoids were evaluated. Thermodynamically stable emulsions were obtained and tested for sensorial analysis after loading the blend of extracts. The selected emulsion was stable when stored at low temperatures (5 degrees C), for which after 120 days the concentration of quercetin and rutin were above their limit of quantification, i.e., 2.8 +/- 0.39 mu g/mL and 30.39 +/- 0.39 mu g/mL, respectively. Spreadability, low rupture strength and adhesiveness were shown to be similar to a conventional topical product. Higher brittleness, pseudo-plastic, and viscoelastic behaviors were also recorded for the developed phytocosmetic sunscreen. The product presented a Critical Wavelength of 387.0 nm and ultraviolet rays A and B (UVA/UVB) rate of 0.78, confirming that the developed formulation shows capacity for UVA/UVB protection, protecting skin against damages caused by ultraviolet (UV) radiation. Rutin was shown to permeate the skin barrier and was also quantified in the stratum corneum (3.27 +/- 1.92 mu g/mL) by tape stripping and retention test (114.68 +/- 8.70 mu g/mL). The developed flavonoid-enriched phytocosmetic was shown to be non-irritant to skin by an in vitro assay. Our results confirm the antioxidant activity, sun protection, and physical properties of the developed phytocosmetic for topical application810CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São PauloSem informaçãoSem informação2015/25533-7; 2017/14757-
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Evaluation of in vitro solar protection factor (spf), antioxidant activity, and cell viability of mixed vegetable extracts from dirmophandra mollis benth, ginkgo biloba l., ruta graveolens l., and vitis vinifera l.
Suíça, 2020Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Fernandes, Ana Rita, Foglio, Mary Ann, Mazzola, Priscila Gava, Sousa, Ilza Maria De Oliveira, Sanchez-lopez Elena, Figueiredo, Mariana Cecchetto, Ruiz, Ana Lucia Tasca Gois, Souto, Eliana BarbosaAbstract:The aim of this study was to validate a HPLC method for the assay of flavonoids in extracts obtained from natural sources, i.e., from Dirmophandra mollis Benth, Ginkgo biloba L., Ruta graveolens L., and Vitis vinifera L. The potential sun protecting effect, antioxidant activity, and cell viability of the extracts were also determined. Individual extracts (obtained from each individual species) and a mixed extract (containing the four extracts) were analyzed by the validated HPLC method for the identification of flavonoids and quantification of rutin and quercetin. An in vitro cell viability study was carried out using the neutral red method. The in vitro sun protection factor was determined by spectral transmittance and in vitro antioxidant efficacy was evaluated against DPPH, ABTS, and AAPH radicals. The HPLC method used for the identification and quantification of flavonoids in extracts exhibited linearity, precision, accuracy, and robustness. Detection and quantification limits were, respectively, 2.881 +/- 0.9 mu g.mL(-1) and 0.864 +/- 0.9 mu g.mL(-1) for quercetin, and 30.09 +/- 1 mu g.mL(-1) and 9.027 +/- 1.1 mu g.mL(-1) for rutin. All extracts did not affect cell viability at the evaluated concentration range and exhibited a sun protection effect and antioxidant activity. Among the evaluated extracts, Ginkgo biloba L. and the mixed extract depicted the most expressive antioxidant activity. The mixed extract exhibited sunscreen protection against ultraviolet A (UVA) and ultraviolet B (UVB) and a Critical Wavelength of 372.7 +/- 0.1. Our results translate the enhanced flavonoids' composition of the mixed extract, which may be a potential alternative over sunscreens and antioxidants in pharmaceutic/cosmetic formulations811CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São PauloSem informaçãoSem informação2015/25533-7; 2017/14757-
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In vitro SPF and photostability assays of emulsion containing nanoparticles with vegetable extracts rich in flavonoids
American Association of Pharmaceutical Scientists, 2019Co-Authors: Cefali, Leticia Caramori, Ataide, Janaina Artem, Eberlin Samara, Gonçalves, Fernanda Cristina Da Silva, Fernandes, Ana Rita, Marto Joana, Ribeiro, Helena Margarida, Foglio, Mary Ann, Mazzola, Priscila Gava, Souto, Eliana BarbosaAbstract:The aim of study was to determine the in vitro sun protection factor (SPF) and the photostability profile of a topical formulation composed of nanoparticles loaded with vegetable extracts and to assess its physicochemical properties. Chitosan/tripolyphosphate (TPP) nanoparticles loaded with flavonoids-enriched vegetable extracts (Ginkgo biloba L., Dimorphandra mollis Benth, Ruta graveolens, and Vitis vinifera L.) were produced and characterized for their morphology, mean particle size, zeta potential, and encapsulation efficiency. A final topical formulation was obtained by dispersing chitosan/TPP nanoparticles in an o/w emulsion. Results showed that nanoparticles dispersion exhibited yellowish color, spherical shape, and uniform appearance. Extract-loaded chitosan/TPP nanoparticles showed a mean particle size of 557.11±3.1 nm, polydispersity index of 0.39±0.27, zeta potential of +11.54±2.1 mV, and encapsulation efficiency of 75.89% of rutin. The recorded texture parameters confirm that the developed formulation is appropriate for skin application. The SPF obtained was 2.3±0.4, with a Critical Wavelength of 387.0 nm and 0.69 UVA/UVB ratio. The developed formulation exhibited photostability, allowing the release of flavonoids from nanoparticles while retaining rutin into the skin in a higher extension.The authors acknowledge FAPESP (grant number 2015/25533-7 and 2017/14757-7), CAPES, and CNPq agencies for the financial support of this study. The authors also acknowledge the financial support received from the Portuguese Science and Technology Foundation (FCT/MCT) and from the European Funds (PRODER/COMPETE) under the project reference M-ERA-NET/0004/2015-PAIRED, co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio