Papers by Valeria Weiss Angeli
Research, Society and Development, 2021
Lignocellulosic nanofibers derived from tobacco stalk can have countless applications in polymers... more Lignocellulosic nanofibers derived from tobacco stalk can have countless applications in polymers composites, textile, cosmetics, and pharmaceuticals. Thus, it is important to evaluate biomass characteristics such as the presence of nicotine. In this study, nanofibers were obtained by mechanical fibrillation while cellulose content (0.5 and 2.0%) and drying methods were varied. Nanofibers were characterized by thin layer chromatography, 1H NMR, morphological analysis, α-cellulose content, Fourier transform infrared spectroscopy, X-ray diffraction and thermal analysis. Results demonstrate the absence of nicotine in tobacco stalk. The grinding mill process was efficient to produce by freeze-drying, nanofibers with fiber’s mean diameter of ~30 nm. Solid concentrations can influence the diameter of obtained fibers. Thermal stability increased and crystallinity decreased when alkali treatment was applied. The characterization techniques applied enable the evaluation of tobacco stalk and ...
Revista de Ciências Farmacêutica Básica e Aplicadas - RCFBA, 2020
The skin is the largest and most exposed organ of the human body, therefore subject to diseases a... more The skin is the largest and most exposed organ of the human body, therefore subject to diseases and alteration of its appearance. Among these alterations, the cutaneous hyperchromia may be cited. Currently, the market offers numerous products with depigmenting action to the treatment of such disorders. The aim of this work was to analyze depigmenting products commercialized in establishments in the city of Bento Gonçalves (RS, Brazil) and websites of cosmetic companies. It was found 45 products with depigmenting action and, from these, 59 different active agents were identified. The main active compounds found were kojic acid, arbutin, ascorbic acid, hydroquinone and glycolic acid. Another observed data was that in 78% of the studied products the active substances were being used in combination. The most used vehicles were also studied as a reference to the use of sunscreen in the treatment of cutaneous hyperchromia. The present work had identified in the market a variety of products with depigmentation action and, because of this, it aims to serve as a reference to the healthcare professionals, especially at the prescribing moment, looking for the best results, with regards to treatment efficiency and safety.
Materials Research, 2020
The clay minerals have characteristics and properties that allow their applicability in the cosme... more The clay minerals have characteristics and properties that allow their applicability in the cosmetic area, being incorporated into formulations as an active principle. Therefore, the aim of this work is characterizing and evaluating the influence of a clay from Miracema do Norte, Tocantins, Brazil, named Clay V, on the physicochemical characteristics of a hydrophilic gel of Aristoflex , a copolymer of the neutralized acryloyldimethyltaurate and vinylpyrrolidone sulphonic acid. Clay V was decontaminated and characterized through microbiological evaluation, crystalline phases present by X-Ray Diffraction (XRD), chemical composition by X-Ray Fluorescence (XRF), thermogravimetric analysis (TGA) and granulometric distribution by sieving. Gels were prepared using Clay V with particles in the range ≤ 180 μm in three different concentrations: 1%, 3% and 5% (w/w) and a standard gel without clay. The formulations were evaluated according to organoleptic characteristics, pH, viscosity, spreadability and the centrifugation test. The microbiological evaluation showed that the clay sample is in compliance with the parameters established by the legislation. The following mineral phases were identified by XRD: kaolinite, illite, vermiculite and quartz, mainly composed of silica and alumina according to XRF. Thermal analysis showed that the clay has two thermal decomposition reactions, the largest being 547.6°C. The granulometric analysis identified that the largest fraction (63.22%) was of particles with sizes greater than 710 μm. The organoleptic characteristics presented by the formulations were suitable, with characteristic gel odor, homogeneous appearance, soft and refreshing texture and staining based on the concentration of Clay V used. The obtained pH values were within the range between 5.5 and 6.5, and it was verified that the gel has high spreadability, distributing evenly on the skin. The values obtained for viscosity showed that the formulations are non-Newtonian fluids with pseudoplastic behavior. The centrifugation test showed that the formulations are stable, with no phase separation. The results obtained with the tests showed that the natural clay V material is beneficial in cosmetic products and can be used for incorporation in cosmetic gel formulations of Aristoflex type.
Evaluation and characterization of Melo Bentonite clay for cosmetic applications
Applied Clay Science, 2019
Abstract Clays are used in cosmetology with different applications, which are conditioned to the ... more Abstract Clays are used in cosmetology with different applications, which are conditioned to the chemical and mineralogical composition and physical-chemical characteristics of these materials. Therefore, the aim of this work was to evaluate the potential application of Melo Bentonite (BEM), clay from Uruguay through different tests. Initially, it was performed the characterization of BEM by X-ray Diffraction (XRD), X-ray fluorescence spectroscopy (XRF), thermal analysis (TGA/DTG), particle size distribution and surface area. The microbial content of natural Melo Bentonite clay was also verified. Two calamine suspensions were formulated with bentonite clay, one containing BEM and the other containing bentonite clay (BE), both at concentration of 5% w/w in glycerin. Bentonite clay was used in accordance to standard. The suspensions were characterized through tests of sedimentation rate, viscosity and pH determination. The physical-chemical characterization of BEM indicated compatible characteristics with those of clay; it was observed only smectite and quartz reflections as crystalline phases and in terms of chemical composition the major presence of silicon, aluminum and magnesium was verified. The microbiological evaluation showed that microbial content of Melo Bentonite presents acceptable limits, according to the Brazilian legislation for cosmetic products. BE was tested by a suspending agent. The sedimentation amount obtained for the suspention that was prepared with BEM was (0.73 mL/min) and with BE (0.63 mL/min). BEM is a better agent suspensor than BE. The viscosity presented by the sample containing BEM was lower than that containing BE; both of them showed non-Newtonian behavior and pseudoplastic flow. The pH of the sample containing BEM was close to neutral (7.72 ± 0.005), while the pH of the sample containing BE was 8.17 ± 0.026. The results showed a possible application of BEM in cosmetic products.
Rev Cienc Farm Basica Apl, Dec 1, 2012
Salvia officinalis (L.), or common sage, is an aromatic herb that has been used in medicine and c... more Salvia officinalis (L.), or common sage, is an aromatic herb that has been used in medicine and cooking since ancient times and has been investigated for the treatment of various diseases, especially infections and skin inflammation. We conducted phytochemical prospecting and quality control with hydroalcoholic extracts of dried sage, to identify active compounds in the plant. The aim was to assess antibacterial and antifungal activity against Staphylococcus aureus, Streptococcus agalactiae, Candida albicans and Candida tropicalis. Antimicrobial susceptibility was investigated in vitro by agar-overlay and well-diffusion techniques, in which disc and well were used. Salvia officinalis (L.) was not effective against Streptococcus agalactiae, Candida albicans or Candida tropicalis, but best results were observed for antibacterial activity against Staphylococcus aureus. Considering the results of the inhibition tests presented here, we suggest that cosmetic formulations containing Salvia officinalis (L.) could contribute to inhibitor of pathogens in the skin microbiota.
Physical and chemical characterization and method for the decontamination of clays for application in cosmetics
Applied Clay Science, 2016
Abstract Clays are materials originated from rock decomposition, made up of clay minerals and non... more Abstract Clays are materials originated from rock decomposition, made up of clay minerals and non-clayish minerals. Their applicability in the field of cosmetics depends on their chemical and mineralogical composition. In view of their huge bioburden there is the need to submit them to effective decontamination before they are incorporated into cosmetics. The present work involved the characterization of four different samples of clays originated from the sand extraction residue of mining activities in the hinterland of Sao Paulo state, Brazil. Characterization was performed with the aid of tools like X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA/DTA), particle size distribution by laser dispersion, surface area (BET method) and Fourier transform infrared spectroscopy (FTIR). Besides, it aims to evaluate the bioburden of these clays, as well as to propose a method for the decontamination of these samples. The average particle diameter varied from 3.6 to 24.1 μm, kaolinite and illite being the main mineralogical phases to be identified. The proposed method for decontamination employed a combination of ethanol 70% and dry heat at 120 °C in an oven for 24 h. The decontamination was effective in reducing samples bioburden, leaving the clays within the limits required for cosmetics application.
Materials Research, 2011
Polymers are often used to coat tablets for controlled drug release. The purpose of this study is... more Polymers are often used to coat tablets for controlled drug release. The purpose of this study is to evaluate the solubility of the HPMC and PVA blend compared to isolated polymers in solutions with a pH of biological fluids (6 and 1.2) and the dissolution of capsules obtained using theophylline granules produced with the HPMC/ PVA 25/75 blend as a matrix and as coating. HPMC is completely solubilized in the medium that simulates the pH of the stomach and intestine, and PVA is the polymer that allows controlling the solubility of the blend in the medium, with a differents pH. The dissolution time was monitored by UV absorbance with maximum theophylline at 269 nm. The theophylline was released immediately in the granules, and in the capsules 78.4% after 30 minutes and 97.4%, after 120 minutes. Thus, PVA can potentially control the drug solubilization, contributing to obtaining modified release systems.
Journal of Pharmacy and Pharmacology, 2010
Objectives This study aimed to investigate the distribution and release profile in the skin of a ... more Objectives This study aimed to investigate the distribution and release profile in the skin of a lipophilic model molecule, octylmethoxycinnamate (OMC), loaded in poly(ε-caprolactone) nanocapsules (NC) by the Franz cell method. Methods Nanocapsules were formulated in a hydroxyethylcellulose gel and compared to the same gel containing 5% of free OMC as control. A new extraction method was used to discriminate the OMC still entrapped in the NC from free OMC released in the skin strata. The OMC extraction from the skin was performed using acetonitrile, which broke the NC, or isopropyl myristate, which kept the NC intact. Key findings When isopropylmyristate was used to determine the OMC released from NC, the results showed that more than 80% of the OMC was released from the NC at the skin surface after 6 h, whereas only 30% was released in the stratum corneum and epidermis. Conclusions It is suggested that the mechanism of release is different at the surface and in viable skin, probabl...
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Papers by Valeria Weiss Angeli