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1.
Braz. J. Pharm. Sci. (Online) ; 56: e18575, 2020. tab, graf
Article in English | LILACS | ID: biblio-1285517

ABSTRACT

Buccal route of administration has many advantages such as improving patient compliance, bypassing the GIT and hepatic first pass effect. The objectives are to formulate mucoadhesive buccal tablet using Mefenamic acid and compatible excipients, and to evaluate the product using quality control tests and in vitro tests. The ingredients were subjected to Differential Scanning Calorimetry and Fourier Transform Infrared Spectroscopy studies for compatibility test and the results showed no interaction. Two batches of mefenamic buccal tablet were prepared. The tablet thickness and diameter are 3.75 mm and 12 mm respectively. All tablets are within the specification of +/- 5%. The in-house tablet hardness is 6.8-15kg and percent friabilation is not more than 0.8%. The disintegration test showed that all tablets disintegrated within 4 hours. The content uniformity showed that tablets are within the range of 85%-115%. The tablet weight is within the 5% range. The percent swelling is 53.83% to 58.86% and moisture absorption is 14.79% to 15.56%. The surface pH of the tablet is close to the salivary pH, which means that it would not irritate the buccal mucosa. The buccal tablet has a mucoadhesiveness of 0.196 to 0.200. There was no change in pH and size after subjecting it to stability studies in human saliva. Drug release studies showed 80.7% to 83.4% after 3 hours. Even after 3 months of subjecting the tablets to 40 ºC and 75% RH, results are within acceptable range. The results show the potential of the formulation as a mucoadhesive buccal tablet.


Subject(s)
Mefenamic Acid/analysis , Mouthwashes/analysis , Quality Control , Tablets/pharmacology , Calorimetry, Differential Scanning/methods , Spectroscopy, Fourier Transform Infrared/methods
2.
J. oral res. (Impresa) ; 8(supl.1): 19-23, ago. 9, 2019. ilus
Article in English | LILACS | ID: biblio-1141501

ABSTRACT

Objectives: The aim of this study was to evaluate chemical and topographical changes in the intaglio zirconia surface induced by chemical conditioning solutions using FTIR and SEM analysis. Material and method: twelve plates for each FTIR and SEM tests from each zirconia materials (UPCERA HT White, BruxZir® Solid Zirconia, and Copran® Multilayer), milled by a Yenadent CAD/CAM system, sintered and divided randomly into a three groups. A different surface conditioning was applied to the intaglio surface of each group: 30% hydrogen peroxide, 30% citric acid and control group. Result and discussion: by using of the FTIR spectroscopy, an evidence of new bands formation appeared at 1637cm-1 and 3352cm-1 due to the high oxidizing effect of hydrogen peroxide, and at 630cm-1 and 1663cm-1 due to the chelating action of citric acid, and simultaneously, SEM assessment of the surface topography took place, to identify lines, scratches, or surface dissociation that appeared on the intaglio zirconia surface after conditioning. Conclusion: such analysis provides an enhancement of new convenient, less expensive, reliable trials to improve micro-bond strength of luting cement to Y-TZP ceramics.


Subject(s)
Humans , Resins, Synthetic , Zirconium/analysis , Spectroscopy, Fourier Transform Infrared/methods , Microscopy, Electron, Scanning , Dental Cements , Hydrogen Peroxide
3.
São Paulo; s.n; s.n; 2018. 206 p. graf, tab.
Thesis in Portuguese | LILACS | ID: biblio-970094

ABSTRACT

O uso de ferramentas estatísticas no ciclo de vida de um produto farmacêutico permite verificar e controlar o processo tendo como objetivo a sua melhoria contínua. No presente estudo foi avaliada a estabilidade e a capacidade estatística do processo de fabricação dos comprimidos revestidos de lamivudina 3TC e zidovudina AZT (150 + 300 mg) fabricados pela Fundação para o Remédio Popular "Chopin Tavares de Lima" (FURP). Esse medicamento, distribuido gratuitamente pelo programa DST/AIDS do Ministério da Saúde, e fabricado por compressão direta, processo rápido que permite a implementação futura da tecnologia analítica de processo (Process Analytical Technology - PAT). No Capítulo I foi realizada avaliação retrospectiva da variabilidade de atributos criticos da qualidade de 529 lotes dos comprimidos fabricados de acordo com a RDC ANVISA 17/2010 e as monografias oficiais, sendo tais atributos: peso médio, uniformidade de dose unitária e % m/v de fármaco dissolvido, antes e após o revestimento. O objetivo foi identificar eventuais causas especiais de variabilidade dos processos que permitam melhorias contínuas. No Capitulo II foi desenvolvida metodologia analítica empregando a espectroscopia no infravermelho próximo com transformada de Fourier para a avaliação da homogeneidade da mistura dos pós. Nesse estudo foram analisadas amostras de misturas dos fármacos lamivudina 3TC e zidovudina AZT e mistura excipiente, empregando como método de referência a CLAE, para a quantificação desses dois fármacos. No Capitulo I, a avaliação do processo para o peso médio revelou a necessidade de investigação das causa especiais de variabilidade, evidenciada por meio das cartas de controle. Os resultados do ano de 2015 indicaram necessidade de centralização e de consistência do processo, com redução de probabilidade de falha. As cartas de controle para uniformidade de dose unitária, no ano de 2013, revelaram menor variabilidade do processo. Porem, nesse ano, a análise estatística para a dissolução revelou processo descentralizado e sem consistência, com maior evidência para o fármaco 3TC que demonstrou menor desempenho, Cpk<1,0. A avaliação da estabilidade e da capacidade do processo de fabricação de comprimidos de lamivudina + zidovudina (150+300 mg), no período de 2012 a 2015, permitiu o maior entendimento de suas fontes de variação. Foi possível detectar e determinar o grau dessa variação e seu impacto no processo e nos atributos críticos de qualidade do produto com evidentes oportunidades de melhoria do processo, reduzindo os riscos para o paciente. No capítulo II, no desenvolvimento do método, as estatísticas de validação revelaram que os menores valores de BIAS foram observados para a 3TC, 0,000116 e 0,0021, respectivamente para validação cruzada e validação. Os valores de BIAS próximos a zero indicaram reduzida porcentagem de variabilidade do método. O presente estudo demonstrou a viabilidade do uso do modelo desenvolvido para a quantificação da 3TC e AZT por FT-NIR apos ajustes que contribuam para a elevação de R, R2 e RPD para valores aceitáveis. Valores de RPD acima de 5,0 que permitem o uso do modelo para uso em controle de qualidade


The use of statistical tools in the life cycle of a pharmaceutical product allows verifying and controlling the process aiming at its continuous improvement. In the present study, the stability and statistical capacity of the lamivudine coated tablets 3TC and zidovudine AZT (150 + 300 mg) manufactured by the Chopin Tavares de Lima Foundation (FURP) were evaluated. This drug, distributed free of charge by the Ministry of Health's DST/AIDS program, is manufactured by direct compression, a rapid process that allows the future implementation of Process Analytical Technology (PAT). In Chapter I, a retrospective evaluation of the variability of critical quality attributes of 529 batches of tablets manufactured was carried out, such attributes being: mean weight, unit dose uniformity and % m/v of dissolved drug substances, before and after coating. The objective was to identify possible special causes of variability of the processes that allow continuous improvements. In Chapter II an analytical methodology was developed employing the near infrared spectroscopy with Fourier transform for the evaluation of the homogeneity of the powder mixture. In this study, samples of mixtures of the drugs lamivudine 3TC and zidovudine AZT and excipient mixture were analyzed, using as reference method the HPLC, for the quantification of these two drugs. In Chapter I, the evaluation of the process for the mean weight revealed the need to investigate the special cause of variability, as evidenced by the charts. The results of the year 2015 indicated the need for centralization and process consistency, with a reduction in the probability of failure. The control charts for unit dose uniformity, in the year 2013, revealed less process variability. However, in that year, the statistical analysis for dissolution revealed a decentralized process with no consistency, with greater evidence for the 3TC drug that showed lower performance, Cpk<1.0. The evaluation of the stability and capacity of the lamivudine + zidovudine tablet manufacturing process (150 + 300 mg) in the period from 2012 to 2015 allowed a better understanding of its sources of variation. It was possible to detect and determine the degree of this variation and its impact on the process and the critical quality attributes of the product with evident opportunities to improve the process, reducing risks for the patient. In Chapter II, in the development of the method, the validation revealed that the lowest values of BIAS were observed for 3TC, 0.000116 and 0.0021, respectively for cross validation and validation. BIAS values close to zero indicated a reduced percentage of variability of the method. The present study demonstrated the feasibility of using the model developed for the quantification of 3TC and AZT by FT-NIR after adjustments that contribute to the elevation of R, R2 and RPD to acceptable values. RPD values above 5.0 that allow the use of the model for use in quality control


Subject(s)
Tablets/analysis , Zidovudine/analysis , Statistical Analysis , Spectroscopy, Fourier Transform Infrared/methods , Lamivudine/analysis , Validation Study , Drug Compounding/instrumentation
4.
São José dos Campos; s.n; 2018. 41 p. il., tab., graf..
Thesis in Portuguese | LILACS, BBO | ID: biblio-1015655

ABSTRACT

Os estudos em laboratório devem ser realizados para verificar e comprovar a eficácia destes novos materiais, equipamentos, técnicas e tecnologias, e sendo considerados aprovados, uma outra etapa in vivo deverá ser realizada. O advento da odontologia adesiva já causou profundas mudanças na prática da odontologia. A proposta deste trabalho foi avaliar in vitro, o efeito da termociclagem, em diferentes temperaturas (5°C, 55°C), soluções (água destilada, óleo mineral), quantidade de ciclos (500, 5.000, 10.000), utilizando um material restaurador universal nanohíbrido fotopolimerizável contendo carga inorgânica em uma matriz de metacrilato e um sistema de cimentação à base de resina composta de polimerização dual. A finalidade da termociclagem é o envelhecimento dos materiais pelo mecanismo do "choque térmico". O objetivo deste trabalho foi demonstrar se a termociclagem interfere ou não nas propriedades físicas e químicas destes materiais. Foram confeccionados 90 corpos de prova (cp) de cada material, cinco de cada grupo, (cpCRc = corpos de prova do cimento resinoso com YTZP, cpCRs= corpos de prova do cimento resinoso sem Y-TZP, e cpRC= corpos de prova da resina composta), que foram armazenados em água destilada, até o início da termociclagem. Estes espécimes receberam o tratamento térmico (nas distintas soluções) e após este evento foram realizadas as mensurações de massa, rugosidade, nanodureza e avaliações em MEV/ EDS, FTIR/UATR. Os dados obtidos foram submetidos ao teste Anova três fatores (α = 0,05). Os grupos cpCRc, cpCRs, cpRC não apresentaram alterações e ou modificações nas propriedades físicas e químicas dos materiais, independentemente do tipo de ciclagem, solução, temperatura e número de ciclos. Portanto, o uso da termociclagem, nas temperaturas de (5°C, 55°C), diferentes soluções (água destilada, óleo mineral), quantidade de ciclos (500, 5.000, 10.000) não foi observado o envelhecimento térmico para estes materiais(AU0


Laboratory studies should be performed to verify and prove the efficacy of these new materials, equipment, techniques and technologies, and being considered approved, another in vivo step should be performed. The advent of adhesive dentistry has already caused profound changes in the practice of dentistry. The determination of bond strength of dentin adhesives is a matter of great importance and interest in our profession. The purpose of this work is to evaluate in vitro the effect of thermocycling at different temperatures (5 °C, 55 °C), solvents (distilled water, mineral oil), number of cycles (500, 5.000, 10.000) and a universal nano-hybrid restorative light-curing material with contains inorganic fillers in a methacrylate matrix and a dual-curing composite-based luting system for permanent adhesive luting. The purpose of thermocycling is thermal and hydrolytic degradation; and the objective of this work is to demonstrate if the thermocycling interferes or not in the study in the physical and chemical properties. A metal matrix was produced to make the specimens (sp). A total of 90 (sp) from each material, five from each group, were prepared (BFX-C = YTZP with resin cement sp, BFX-S = YTZP without resin cement sp, and GRD = composite resin specimens) which were stored in distilled water until the beginning of the thermocycling. The sp received the thermal treatment (the different solvents) and after this event were reached the messages of mass, roughness, hardness. and evaluations in SEM / EDS, FTIR / UATR. Data were obtained from the Anova test (α = 0.05). The groups BFX-C, BFX-S, GRD are the parameters keys and physical properties of the materials, regardless of the type of cycling, solvent, temperature and number of cycles. Therefore, the use of thermocycling, at temperatures of 5 °C, 55 °C, different solvents, mineral oil, amount of heat (500, 5,000, 10,000) was not observed in the thermal heat for these materials(AU)


Subject(s)
Humans , Dental Cements/adverse effects , Spectroscopy, Fourier Transform Infrared/methods , Composite Resins/administration & dosage
5.
Biol. Res ; 51: 49, 2018. tab, graf
Article in English | LILACS | ID: biblio-1011393

ABSTRACT

BACKGROUND: Antarctic bryophytes (mosses and liverworts) are resilient to physiologically extreme environmental conditions including elevated levels of ultraviolet (UV) radiation due to depletion of stratospheric ozone. Many Antarctic bryophytes synthesise UV-B-absorbing compounds (UVAC) that are localised in their cells and cell walls, a location that is rarely investigated for UVAC in plants. This study compares the concentrations and localisation of intracellular and cell wall UVAC in Antarctic Ceratodon purpureus, Bryum pseudotriquetrum and Schistidium antarctici from the Windmill Islands, East Antarctica. RESULTS: Multiple stresses, including desiccation and naturally high UV and visible light, seemed to enhance the incorporation of total UVAC including red pigments in the cell walls of all three Antarctic species analysed. The red growth form of C. purpureus had significantly higher levels of cell wall bound and lower intracellular UVAC concentrations than its nearby green form. Microscopic and spectroscopic analyses showed that the red colouration in this species was associated with the cell wall and that these red cell walls contained less pectin and phenolic esters than the green form. All three moss species showed a natural increase in cell wall UVAC content during the growing season and a decline in these compounds in new tissue grown under less stressful conditions in the laboratory. CONCLUSIONS: UVAC and red pigments are tightly bound to the cell wall and likely have a long-term protective role in Antarctic bryophytes. Although the identity of these red pigments remains unknown, our study demonstrates the importance of investigating cell wall UVAC in plants and contributes to our current understanding of UV-protective strategies employed by particular Antarctic bryophytes. Studies such as these provide clues to how these plants survive in such extreme habitats and are helpful in predicting future survival of the species studied.


Subject(s)
Pigments, Biological/radiation effects , Pigments, Biological/metabolism , Ultraviolet Rays , Cell Wall/radiation effects , Cell Wall/metabolism , Bryophyta/radiation effects , Bryophyta/metabolism , Seasons , Time Factors , Pigmentation/radiation effects , Analysis of Variance , Chromatography, High Pressure Liquid , Spectroscopy, Fourier Transform Infrared/methods , Plant Leaves/radiation effects , Plant Leaves/metabolism , Microscopy, Confocal , Bryophyta/cytology , Antarctic Regions
6.
São Paulo; s.n; s.n; 2017. 105 p. tab, ilus, graf.
Thesis in Portuguese | LILACS | ID: biblio-881629

ABSTRACT

O tratamento farmacológico de patologias bucais é conduzido, geralmente, por via de administração local. No entanto, devido ao pouco tempo de permanência do fármaco no local de ação, esse tratamento pode ser bastante comprometido. Assim, este trabalho teve por objetivo o desenvolvimento de formas farmacêuticas que proporcionem a liberação local de triancinolona na cavidade oral. Foram produzidos filmes e comprimidos mucoadesivos a partir de polímeros naturais como gelana e pectina. Os filmes bucais foram preparados por meio de evaporação do solvente (solvent casting) utilizando diferentes quantidades de polímeros. As matérias-primas e os filmes foram caracterizados fisico quimicamente utilizando espectroscopia vibracional (in-infravermelho com transformada de Fourier e Raman) e difração de raios X. As propriedades físicas e mecânicas dos filmes também foram avaliadas. Além disso, realizou-se os ensaios de mucoadesividade e de dissolução do fármaco. Os comprimidos foram preparados por com-pressão direta usando como base os polímeros naturais. Diferentes parâmetros em relação as misturas e as formulações foram avaliados tais como as propriedades de fluxo dos pós constituintes, peso médio, dureza, friabilidade e desintegração. Em relação aos filmes bucais, estes foram obtidos com sucesso através de um método simples, sem a utilização de agentes reticulantes, ácidos ou solventes orgânicos. Todos apresentaram bons resultados nas propriedades avaliadas, no entanto as formulações com quantidades intermediarias de polímeros foram as melhores. Dentre as formulações de comprimidos preparadas, apenas 4 apresentaram boas características, no entanto, os resultados dos ensaios de dissolução mostraram que estas formulações têm capacidade de agir como sistema de liberação controlada de fármacos


Pharmacological treatment of oral pathologies is usually conducted by local administration. However, due to the short time the drug stays in the site of action, this treatment can be quite compromised. Thus, the objective of this work was to develop pharmaceutical forms that pro-vide the local release of triamcinolone in the oral cavity. Mucoadhesive films and tablets were made from natural polymers such as gellan and pectin. The buccal films were prepared by sol-vent casting using different amounts of polymers. The raw materials and films were characte-rized physically chemically using vibrational spectroscopy (FTIR and Raman) and X-ray diffraction. The physical and mechanical properties of the films were also evaluated. In addi-tion, the mucoadhesive and drug dissolution tests were performed. The tablets were prepared by direct pressing with the natural polymers. Different parameters in relation to mixtures and formulations were evaluated such as the flow properties of the constituent powders, average weight, hardness, friability and disintegration. In relation to oral films, these were successfully obtained by a simple method, without the use of crosslinking agents, acids or organic solvents. All presented good results in the evaluated properties, however the formulations with interme-diate amounts of polymers were the best. Among the tablet formulations prepared, only 4 sho-wed good characteristics, however, the dissolution test results showed that these formulations have the ability to act as a controlled drug delivery system


Subject(s)
Pectins/analysis , Triamcinolone/pharmacology , Microscopy, Polarization/methods , Mouth/immunology , Spectroscopy, Fourier Transform Infrared/methods , Tablets/pharmacokinetics , Technology, Pharmaceutical/instrumentation
7.
Biol. Res ; 50: 14, 2017. tab, graf
Article in English | LILACS | ID: biblio-838965

ABSTRACT

BACKGROUND: Kidney diseases are a global health problem. Currently, over 2 million people require dialysis or transplant which are associated with high morbidity and mortality; therefore, new researches focused on regenerative medicine have been developed, including the use of stem cells. RESULTS: In this research, we generate differentiated kidney cells (DKCs) from mouse pluripotent stem cells (mPSCs) analyzing their morphological, genetic, phenotypic, and spectroscopic characteristics along differentiation, highlighting that there are no reports of the use of Fourier transform infrared (FTIR) spectroscopy to characterize the directed differentiation of mPSCs to DKCs. The genetic and protein experiments proved the obtention of DKCs that passed through the chronological stages of embryonic kidney development. Regarding vibrational spectroscopy analysis by FTIR, bands related with biomolecules were shown on mPSCs and DKCs spectra, observing distinct differences between cell lineages and maturation stages. The second derivative of DKCs spectra showed changes in the protein bands compared to mPSCs. Finally, the principal components analysis obtained from FTIR spectra allowed to characterize chemical and structurally mPSCs and their differentiation process to DKCs in a rapid and non-invasive way. CONCLUSION: Our results indicated that we obtained DKCs from mPSCs, which passed through the chronological stages of embryonic kidney development. Moreover, FTIR spectroscopy resulted in a non-invasive, rapid and precise technic that together with principal component analysis allows to characterize chemical and structurally both kind of cells and also discriminate and determine different stages along the cell differentiation process.


Subject(s)
Animals , Mice , Cell Differentiation/physiology , Spectroscopy, Fourier Transform Infrared/methods , Pluripotent Stem Cells/physiology , Kidney/cytology , Immunohistochemistry , Gene Expression , Cells, Cultured , Fluorescent Antibody Technique , Principal Component Analysis , Pluripotent Stem Cells/cytology , Real-Time Polymerase Chain Reaction
8.
Braz. j. pharm. sci ; 52(4): 645-651, Oct.-Dec. 2016. graf
Article in English | LILACS | ID: biblio-951876

ABSTRACT

ABSTRACT Skin aging causes changes such as wrinkles and flaccidity leading to a large demand for aesthetic procedures, including dermal filling. A key agent in dermal filling is hyaluronic acid (HA), which is a naturally occurring glycosaminoglycan. However, it is a hydrophilic macromolecule that experiences great difficulty in crossing the skin barrier causing most commercial formulations containing it to be injectable, which in turn brings risks since they involve an invasive technique. In that sense, the aim of this study was to develop and characterize nanoparticles obtained from ionic interaction between HA and lysine (Lys) for use as a potential agent of dermal filling for topical application, increasing and improving its applicability and safety. To this end, nanoparticles were obtained by dripping of Lys over HA under magnetic stirring. A nanometric size was confirmed and a suitable surface charge was obtained by zeta potential. Nanoparticles were almost spherical in shape with a smooth surface. Interaction between raw materials for preparing nanoparticles was studied by FTIR and NMR spectroscopy and an ionic interaction was confirmed. These physicochemical features suggest that obtained nanoparticles can be further used as a topical dermal filling.


Subject(s)
Skin Aging/genetics , Nanotechnology/classification , Hyaluronic Acid/analysis , Lysine/analysis , Magnetic Resonance Spectroscopy/methods , Spectroscopy, Fourier Transform Infrared/methods , Dermal Fillers/adverse effects
9.
Braz. j. pharm. sci ; 52(4): 715-725, Oct.-Dec. 2016. tab, graf
Article in English | LILACS | ID: biblio-951884

ABSTRACT

ABSTRACT Zidovudine (AZT) mucoadhesive solid dispersions (SD) were prepared using a sodium starch glycolate (SSG) and hypromellose phthalate (HPMCP) mixtures as carrier to enhance the intestinal permeability and bioavailability of zidovudine. SDs were prepared using the co-precipitation method followed by solvent evaporation and characterized according to their physicochemical properties such as particle size, crystallinity, thermal behavior, and liquid uptake ability. In vitro drug dissolution, mucoadhesiveness and AZT intestinal permeability were also determined. Thermal behavior and X-ray diffraction patterns demonstrated the amorphous state of AZT in SD systems. The HPMCP polymer restricted the liquid uptake ability in the acid medium; however, this property significantly increased with higher pH values. SDs allowed drug dissolution to occur in a controlled manner. HPMCP decreased the dissolution rates in the acid medium. The mucoadhesiveness of SDs was demonstrated and the permeability of AZT carried in solid dispersions was significantly improved. The effect of the SD carrier polymers on blocking efflux pump can be an important approach to improve the bioavailability of AZT.


Subject(s)
Permeability , Zidovudine/analysis , In Vitro Techniques/instrumentation , Spectroscopy, Fourier Transform Infrared/methods , Drug Liberation , Intestines
10.
Braz. j. pharm. sci ; 52(2): 239-250, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-795002

ABSTRACT

ABSTRACT The objective of this research was to design a new colon-targeted drug delivery system based on chitosan. The properties of the films were studied to obtain useful information about the possible applications of composite films. The composite films were used in a bilayer system to investigate their feasibility as coating materials. Tensile strength, swelling degree, solubility, biodegradation degree, Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Scanning electron microscope (SEM) investigations showed that the composite film was formed when chitosan and gelatin were jointly reacted jointly. The results showed that a 6:4 blend ratio was the optimal chitosan/gelatin blend ratio. In vitro drug release results indicated that the Eudragit- and chitosan/gelatin-bilayer coating system prevented drug release in simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). However, the drug release from a bilayer-coated tablet in SCF increased over time, and the drug was almost completely released after 24 h. Overall, colon-targeted drug delivery was achieved by using a chitosan/gelatin complex film and a multilayer coating system.


RESUMO O objetivo desta pesquisa foi planejar um novo sistema de liberação de fármacos direcionado ao cólon, utilizando quitosana. Estudaram-se as propriedades dos filmes a fim de obter informações úteis sobre a aplicação desses filmes compósitos. Utilizaram-se os filmes compósitos em sistema de bicamada para investigar a sua viabilidade como materiais de revestimento. Estudos de resistência à tração, grau de intumescimento, solubilidade, grau de biodegradação, no infravermelho por transformada de Fourier (FTIR), de calorimetria diferencial de varredura (DSC) e de microscopia eletrônica de varredura (SEM) mostraram que o filme compósito se formou quando a quitosana e a gelatina reagiram entre si. Os resultados mostraram que a mistura de proporção ótima foi de 6:4 de quitosana:gelatina. Resultados da liberação do fármaco in vitro indicaram que o sistema de revestimento de Eudragit e bicamada de quitosana/gelatina impediu a liberação de fármaco em fluido intestinal simulado (SIF) e em fluido gástrico simulado (SGF). Entretanto, a liberação de fármaco do comprimido revestido em bicamada no SCF aumentou ao longo do tempo e o fármaco foi quase completamente liberado após 24 h. Em geral, se obteve a forma de liberação dirigida ao cólon, utilizando filme complexo de quitosana/gelatina e sistema de revestimento multicamada.


Subject(s)
Colon/drug effects , Hydrocortisone/pharmacokinetics , Calorimetry, Differential Scanning/methods , Chitosan/pharmacokinetics , Microscopy, Electron, Scanning/methods , Spectroscopy, Fourier Transform Infrared/methods , Tablets/pharmacokinetics
11.
São Paulo; s.n; s.n; 2016. 197 p. graf, tab.
Thesis in Portuguese | LILACS | ID: biblio-881739

ABSTRACT

A nistatina (NYS) é o fármaco de primeira escolha no tratamento da candidíase oral, que frequentemente acomete mais os indivíduos imunocomprometidos e pacientes com outras desordens (diabetes não tratada, neoplasias, imunodeficiências). No mercado brasileiro, a NYS é encontrada na forma de suspensão oral aquosa, onde o procedimento para sua administração consiste em bochechar o medicamento. Apesar de haver a indicação de que se mantenha o contato direto entre fármaco e a mucosa oral, na qual se encontra a Candida spp., o que aumentaria expressivamente o sucesso terapêutico, a suspensão não apresenta tal propriedade. Assim, a NYS que é fármaco com ação efetiva contra a candidíase oral, é considerada pertencente à Classe IV do Sistema de Classificação Biofarmacêutica, ou seja, apresenta baixa solubilidade e baixa permeabilidade. A baixa solubilidade pode comprometer sua disponibilidade na cavidade oral, e consequentemente, sua ação farmacológica. Diante desse quadro, o objetivo do presente trabalho foi o desenvolvimento de dispersões sólidas de NYS para o tratamento da candidíase oral, e sua posterior incorporação em gel mucoadesivo oral, favorecendo a formulação no local de ação. As dispersões sólidas são sistemas farmacêuticos, onde um fármaco pouco solúvel em água encontra-se dispersado em um carreador, no estado sólido. Os carreadores normalmente são hidrofílicos, o que permite que esses sistemas sejam empregados para aumentar a solubilidade aquosa do fármaco. Assim, foram desenvolvidas as dispersões sólidas de NYS, pelo método de eliminação do solvente, empregando como carreadores, lactose, HPMC, poloxamer 407 e poloxamer 188. Essas foram submetidas à caracterização por análise térmica, usando os ensaios de calorimetria exploratória diferencial (DSC) e termogravimetria/termogravimetria derivada (TG/DTG). Dentre essas dispersões sólidas, aquelas que se mostraram com comportamento térmico sugerindo a formação de um novo "sistema", foram analisadas por meio de ensaio de solubilidade. Dessa forma, a formulação NYS DS G2 (49) se destacou, pois apresentou maior solubilidade em água (4,484 mg/mL); em pH 5,5 (4,249 mg/mL) e em pH 7,0 (4,293 mg/mL), ou seja, houve um aumento de 1,426 vezes em água; 4,227 vezes em pH 5,5; e 2,743 vezes em pH 7,0. Essa formulação foi, por fim avaliada por difração de raio-X e espectroscopia de infravermelho com transformada de Fourier, técnicas que corroboraram com a análise térmica quanto à indicação de formação da dispersão sólida. Por sua vez, essa dispersão sólida foi incorporada em 4 bases de géis mucoadesivos de carbopol ® 934 PNF, alterando apenas a concentração do polímero (0,5; 1,0; 1,5; 2,0 %p/p). Foi observado que a liberação de NYS DS G2 (49) foi superior, quando comparada à liberação de NYS MP a partir do gel, e através do ensaio de mucoadesão, percebeu-se que os géis desenvolvidos apresentaram propriedades mucoadesivas compatíveis com relatos na literatura, independentemente da quantidade de carbopol ® empregada. As características reológicas foram distintas, e foi observado que as formulações Gel A e Gel B, que possuem menor quantidade de polímero, tiverem um indicativo de comportamento de fluido newtoniano, diferente dos demais, o que pode não ser desejado para esse tipo de forma farmacêutica tópica e semi-sólida. Ao final desse trabalho, pode-se concluir que foi possível desenvolver um sistema farmacêutico na forma de dispersão sólida com maior solubilidade que a NYS pura, e sua incorporação em uma forma farmacêutica mucoadesiva, e que a liberação da NYS na forma DS foi muito superior que o fármaco na forma "convencional", o que permite que a NYS esteja mais disponível na cavidade oral, e também junto à mucosa bucal, o que levaria a efeito farmacológico mais efetivo do antifúngico


Nystatin (NYS) is the drug of first choice in the treatment of oral candidiasis that most often affect immunocompromised individuals, and patients with other disorders. In the Brazilian market, NYS is found in the form of aqueous oral suspension, a medication used in the form of mouthwash. Although there is an indication to maintain direct contact between the drug and the oral mucosa, where Candida spp. is found, as well as where therapeutic success would significantly be increased, the suspension has no such property. Thus, the NYS is an effective drug against oral candidiasis, and belongs to Class IV of the Biopharmaceutical Classification System, it has low solubility and low permeability. The low solubility can compromise its availability in the oral cavity, and consequently, its pharmacological action. Given this situation, the objective of this work was the development of solid dispersions of NYS for the treatment of oral candidiasis, and its subsequent incorporation into oral mucoadhesive gel, in order to facilitate its action. Solid dispersions are pharmaceutical systems, in which a solid drug poorly soluble in water is dispersed in a carrier. These carriers are usually hydrophilic, and this allows the systems to be employed in order to increase the aqueous solubility of the drug. Thus, the solid NYS dispersions were developed by the solvent evaporation method, employing lactose, HPMC, poloxamer 407 and poloxamer 188 as carrier. These samples were subjected to characterization by thermal analysis, using differential scanning calorimetry (DSC) and thermogravimetry / derivative thermogravimetry (TG / DTG). Among these solid dispersions, those samples which showed a specific thermal behavior suggesting the formation of new "system" were analyzed by solubility test. Thus, the NYS DS G2 formulation (49) stood out, once it showed greater solubility in water (4.484 mg/mL); at pH 5.5 (4.249 mg/mL) and pH 7.0 (4.293 mg/mL), in other words, an increase of 1,426 times in water; 4,227 times at pH 5.5; and 2,743 times at pH 7.0. This formulation was finally evaluated by X-ray diffraction, infrared spectroscopy with Fourier transform, techniques that corroborate the thermal analysis, indicating the formation of the solid dispersion. On the other hand, this solid dispersion was incorporated into 4 Carbopol ® 934 PNF mucoadhesive gels, with a variation of the polymer concentration. It was observed that NYS is improved of delivery from the gels, employing mucoadhesion test, and was also observed that the gels have mucoadhesive properties consistent with reports in the literature. However, the rheological characteristics are different, and it was observed that the Gel A and Gel B formulations, which has a lower amount of polymer behaved as a Newtonian fluid, which may not be desired for this type of topical gel. As conclusion, it was possible to develop a pharmaceutical system in the form of solid dispersion with greater solubility than the pure NYS, and their incorporation in a mucoadhesive dosage form and the release of NYS as DS was far superior wherein the drug in the "conventional" manner, which allows the NYS is longer available in the oral cavity, and also adjacent to the buccal mucosa, leading to more effective pharmacological effect of the antifungal agent


Subject(s)
Candidiasis, Oral/drug therapy , Nystatin/immunology , Differential Thermal Analysis/statistics & numerical data , Mouth Mucosa , Oral Mucosal Absorption , Solubility , Spectroscopy, Fourier Transform Infrared/methods , Thermogravimetry/methods , X-Ray Diffraction/methods
12.
Indian J Biochem Biophys ; 2014 Jun; 51(3): 237-243
Article in English | IMSEAR | ID: sea-154236

ABSTRACT

Urinary calculi constitute one of the oldest afflictions of humans as well as animals, which are occurring globally. The calculi vary in shape, size and composition, which influence their clinical course. They are usually of the mixed-type with varying percentages of the ingredients. In medical management of urinary calculi, either the nature of calculi is to be known or the exact composition of calculi is required. In the present study, two selected calculi were recovered after surgery from two different patients for detailed examination and investigated by using Fourier-Transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), powder X-ray diffraction (XRD), scanning electron microscopy and energy dispersive analysis of X-rays (EDAX) techniques. The study demonstrated that the nature of urinary calculi and presence of major phase in mixed calculi could be identified by FT-IR, TGA and powder XRD, however, the exact content of various elements could be found by EDAX only.


Subject(s)
Aged , Calcium Oxalate/chemistry , Female , Humans , Male , Microscopy, Electron, Scanning/methods , Middle Aged , Powders , Spectrometry, X-Ray Emission/methods , Spectroscopy, Fourier Transform Infrared/methods , Thermogravimetry/methods , Urinary Calculi/chemistry , X-Ray Diffraction/methods
13.
Braz. j. pharm. sci ; 50(1): 195-202, Jan-Mar/2014. tab, graf
Article in English | LILACS | ID: lil-709548

ABSTRACT

To evaluate binding potential of Prunus domestica gum in tablets formulations. Six tablet batches (F-1B to F-6B) were prepared by wet granulation method, containing Avicel pH 101 as diluent, sodium diclofenac as model drug using 10, 15 and 20 mg of Prunus domestica gum as binder and PVP K30 was used as standard binder. Magnesium stearate was used as lubricant. Flow properties of granules like bulk density, tapped density, Carr index, Hausner’s ratio, angle of repose as well as physical parameters of the compressed tablets including hardness, friability, thickness and disintegration time were determined and found to be satisfactory. The FTIR spectroscopic analysis showed that the formulation containing plant gum is compatible with the drug and other excipients used in tablets formulation. Hence the plant gum has role as a potential binder in tablets formulations. The dissolution profile showed that tablets formulations containing Prunus domestica gum 15 mg/200 mg of total weight of tablet as binder showed better results as compared to PVP K30.


Para avaliar a propriedade aglutinante da goma Prunus domestica em formulações de comprimidos, seis lotes (F-1B para F-6B) foram preparados pelo método de granulação úmida, contendo Avicel pH 101 como diluente e diclofenaco de sódio como fármaco modelo, usando 10, 15 e 20 mg de goma de Prunus domestica como agente aglutinante e PVP K30 como aglutinante padrão. O estearato de magnésio foi utilizado como lubrificante. Propriedades de fluxo dos grânulos, como a densidade, índice de Carr, razão de Hausner, ângulo de repouso, bem como parâmetros físicos dos comprimidos, incluindo o tempo de dureza, friabilidade, espessura e desintegração foram determinados e se mostraram satisfatórios. A análise espectroscópica no FTIR mostrou que a formulação contendo goma vegetal é compatível com o fármaco e outros excipientes utilizados na formulação dos comprimidos. Assim, a goma vegetal tem papel potencial como aglutinante em formulações de comprimidos. O perfil de dissolução das formulações que contêm 15 mg/200 mg do peso total do comprimido em goma de Prunus domestica como aglutinante mostrou melhores resultados comparativamente ao PVP K30.


Subject(s)
Plant Gums/pharmacokinetics , Prunus domestica/chemistry , Diclofenac/pharmacokinetics , Dissolution/analysis , Spectroscopy, Fourier Transform Infrared/methods , Tablets/analysis
14.
Rev. bras. ciênc. saúde ; 18(3): 219-224, 2014. ilus, tab, graf
Article in Portuguese | LILACS | ID: lil-780233

ABSTRACT

O leite é um dos alimentos mais consumidos no mundo,principalmente por crianças e idosos. Em 2007, a Polícia Federal realizou uma operação que apontou um gigantesco esquema de fraudes em leites comercializados no Brasil, constatou-se ainda que 1/3 do leite consumido no Brasil não passava por fiscalização. Muitas são as adulterações: adição de água, soda cáustica, cloreto de sódio, entre outros. No entanto, ainda há outro problema, o da contaminação por fármacos veterinários. Estes podem estar presentes em altas concentrações no leite caso este tenha sido ordenhado dentro do período de carência da vaca. O leite contaminado pode causar sérios dados à saúde do consumidor ou então causar prejuízos para a produção de seus derivados. Objetivo: Desenvolver uma técnica complementar para detectar a presença de resíduos de medicamentosveterinários em amostras de leites. Material e Métodos: Atualmente,com o desenvolvimento tecnológico há muitas técnicas de análisemultielementar que permitem estudar os componentes químicos dedeterminadas amostras. O presente trabalho utiliza a técnica deEspectroscopia no Infravermelho Próximo por Transformada de FourierFT-NIR e a Análise de Componentes Principais PCA para detectar apresença de resíduos do medicamento veterinário em leites. Paraisto, simulou-se adulteração do leite com percentuais de (0,1; 0,5 e10)% de fármaco no leite. Resultados: Crioscopia: 0,539 ºH com0,18% de água; leite não ácido pelo teste do Alizarol; pH 6,71; Gordura:3,25%; Proteína: 3,01%; Lactose: 4,55%; Sólidos: 10,80%. Resíduosdo fármaco foram observados via derivada primeira de espectros derefletância, e análise de PCA em níveis inferiores a 1%. Conclusão:o sistema FT-NIR pôde detectar os resíduos dos fármacos estudadosdentro dos percentuais simulados...


Milk is one of most consumed food by human beings,especially children and elderly. In 2007, the Federal Police conductedan operation that showed an enormous fraud scheme in industrializedmilk in Brazil. In addition, they found out that 1/3 of the milk consumedin Brazil did not pass by inspection. There are several ways to adulteratemilk, such as with addition of water, caustic soda, sodium chlorideand others. However, there is another issue, that is, milk contaminationwith veterinary drugs. These drugs may be present in highconcentrations in milk, in case the cow was milked in the clearanceperiod. Contaminated milk can cause damages to consumers’ healthor injury to the production of derivates. Objective: To develop acomplementary technique to detect the presence of residues ofveterinary drugs in milk samples. Material and Methods: currently,given the technological development, there are many techniquesbased on multielement analysis for studying the chemical componentsof different samples. This paper uses the technique of FourierTransform Near Infrared Spectroscopy and the Principal ComponentsAnalysis (PCA) to detect the evidence of residues of veterinarydrugs in milk. To this end, we simulated adulteration in milk withpercentages of 0.1%, 0.5% and 10% drugs in milk. Results: cryoscopy:0.539 ºH with 0.18% water; non-acid milk according to Alizarol test; pH6.71; Fat: 3.25%; Protein: 3.01%; Lactose: 4.55%; Solids: 10.80%.Drug residues were observed via the first derivative of reflectancespectra and PCA analysis at levels below 1%. Conclusion: The resultwas positive indicating that the FT-NIR system can detected theresidues of studied drugs within the simulated percentage...


Subject(s)
Humans , Female , Cattle , Breast-Milk Substitutes , Diclofenac/pharmacology , Spectroscopy, Fourier Transform Infrared/statistics & numerical data , Spectroscopy, Fourier Transform Infrared/methods , Spectroscopy, Fourier Transform Infrared/veterinary
15.
Pakistan Journal of Pharmaceutical Sciences. 2013; 26 (3): 629-636
in English | IMEMR | ID: emr-142628

ABSTRACT

Solid dispersion technique has been developed many years for improving solubility of water-insoluble drugs, aiming to achieve a better oral bioavailability. However, this technique exhibits many inconveniences when used for large-scale tableting procedures. The objective of current research work was to develop cilnidipine solid dispersions [SDs] to improve the dissolution behaviors of this water-insoluble drug. Moreover, an innovative granulation method was designed to simplify the traditional tableting technology used in solid dispersion technique. Three different kinds of polymers, polyethylene glycol [PEG], polyvinylpyrrolidone [PVP] and poloxamer, were used as carriers to prepare solid dispersions. The interactions in the solid state were characterized by differential scanning calorimetry [DSC], powder Xray diffraction [PXRD] and FT-IR spectroscopy. The designed granulation method was employed to prepare solid dispersion tablets and the formulation was optimized through investigating the dissolution behaviors. The results indicated PEG solid dispersion showed the best effect both on physical characterizations and dissolution studies. Furthermore, all type of solid dispersions significantly improved the dissolution rates when compared to pure drug and its corresponding physical mixture [PM]. The solid dispersion tablets prepared in simplified tableting method exhibited better operability, stability and dissolution behavior than the tablets prepared in traditional ways, which brought more opportunities to solid dispersion technique for industrial production


Subject(s)
Tablets/chemistry , Technology, Pharmaceutical/methods , Water/chemistry , X-Ray Diffraction/methods , Spectroscopy, Fourier Transform Infrared/methods , Poloxamer/chemistry , Polyethylene Glycols/chemistry , Polymers/chemistry , Povidone/chemistry , Powders , Solubility , Dihydropyridines/chemistry , Drug Carriers/chemistry
16.
Arq. bras. med. vet. zootec ; 64(5): 1360-1366, out. 2012. ilus, tab
Article in English | LILACS | ID: lil-655911

ABSTRACT

The objective of this study was to evaluate the CombiScope FTIR equipment based on Fourier Transform Infrared methodology (FTIR), to assess the content of milk urea nitrogen (MUN) in Brazil. Repeatability and reproducibility of CombiScopeTM FTIR (Delta Instruments), and comparison with an enzymatic automated method (Chemspec® 150; Bentley Instruments) were tested to measure raw milk urea nitrogen (MUN). Additionally, MUN levels stability after storage of raw milk samples at 4ºC, and 20ºC for up to 15 days, and capability and precision to detect extraneous urea added as an adulterant to the milk were evaluated by FTIR equipment. There was a high correlation coefficient for the analysis of MUN by FTIR equipment, when compared with the automated enzymatic method, with no significant difference between both. MUN concentration in raw milk remained stable at temperatures of 4ºC for up to 15 days of storage, but after 3 days of storage at 20ºC there was an increase in the MUN levels. The CombiScope FTIR equipment proved to be a reliable method for analysis of MUN content in raw milk. However, results for MUN were not linear with the amount of extraneous urea added to raw milk, having a significant difference for samples when 40mg/dL of urea was added to milk.


O objetivo deste estudo foi realizar a avaliação do CombiScopeTM FTIR (Delta Instruments), um equipamento baseado na espectroscopia de infravermelho por metodologia em Transformada Fourier (FTIR) para a avaliação do teor de nitrogênio uréico no leite (NUL) cru produzido no Brasil. A repetibilidade e reprodutibilidade do CombiScopeTM FTIR (Delta Instruments) e a comparação com um método enzimático automatizado (ChemSpec® 150; Bentley Instruments) foram testados para a medição do nitrogênio uréico no leite (NUL) cru. Adicionalmente, os níveis de NUL após armazenamento das amostras de leite a 4ºC e 20ºC por até 15 dias, e a capacidade e precisão para detectar uréia adicionada de forma fraudulenta ao leite foram avaliados por FTIR. Houve alta correlação entre os métodos FTIR e enzimático automatizado para a análise de uréia, sem diferença significativa entre ambos (p>0,05). A concentração de uréia no leite cru manteve-se estável durante o armazenamento das amostras a 4ºC por até 15 dias. No entanto, após três dias à temperatura de 20ºC houve um aumento nos níveis de uréia. Os resultados obtidos evidenciam que o equipamento CombiScopeTM FTIR é um método confiável para a análise do teor de uréia no leite cru. Entretanto, a detecção de uréia adicionada de forma fraudulenta ao leite cru não foi linearmente proporcional, com diferença significativa para adição de uréia em níveis de 40mg/dL.


Subject(s)
Spectroscopy, Fourier Transform Infrared/methods , Milk/metabolism , Nitrogen/analysis , Urea
17.
Article in English | LILACS | ID: lil-655411

ABSTRACT

Clonazepam (CLZ) is an anticonvulsant benzodiazepine widely used in the treatment of epilepsy. CLZ is a BCS Class II drug and its bioavailability is thus dissolution limited. The objective of the present study was to prepare solid dispersions (SDs) of CLZ by various techniques, using the amphiphilic carrier Gelucire 50/13 in various proportions, to increase its water solubility. Drug-polymer interactions were investigated by Fourier-transform infrared (FTIR) and Ultra-Violet (UV) spectroscopy. The SDs were characterized physically by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A phase solubility study was performed and the stability constant (Ks) was found to be 275.27, while the negative Gibbs free energy (?Gotr) indicated spontaneous solubilization of the drug. The dissolution study showed that the SDs considerably enhanced the dissolution rate of the drug. The FTIR and UV spectra revealed no chemical incompatibility between the drug and Gelucire 50/13. XRD patterns and the DSC profiles indicated the CLZ was in the amorphous form, which explains the improved dissolution rate of the drug from its SDs. Finally, mouth dissolving tablets (MDTs) were prepared from the optimized batches (kneading method) of solid dispersion, using crospovidone and Doshion P544 resin as superdisintegrants. The tablets were characterized by in-vitro disintegration and dissolution tests. The study of the MDTs showed disintegration times in the range 32.0±0.85 to 20.0±1.30 sec and dissolution was faster than for the commercial preparation. In conclusion, this investigation demonstrated the potential of solid dispersions of a drug with Gelucire 50/13 for promoting the dissolution of the drug and contributed to the understanding of the effect of a superdisintegrant on mouth dissolving tablets containing a solid dispersion of a hydrophobic drug.


Subject(s)
Clonazepam , Drug Compounding , Spectroscopy, Fourier Transform Infrared/methods , Solubility , Tablets
18.
Acta cir. bras ; 25(4): 351-356, July-Aug. 2010. graf, tab, ilus
Article in English | LILACS | ID: lil-553243

ABSTRACT

Cutaneous melanoma is the most aggressive type of skin cancer and Ft-Raman spectroscopy has been studied as a potential method that could be a real alternative for early diagnosis of neoplasms. PURPOSE: To qualify the spectral FT-Raman data, in order to differentiate cutaneous melanoma and pigmented nevus. METHODS: For this study, 10 samples of cutaneous melanoma, 9 samples of pigmented nevi, and 10 samples of normal skin were obtained by incisional biopsies performed during plastic surgeries ex vivo, immediately after removing the surgical sample. RESULTS: The FT-Raman spectra of each group presented a high correlation between the elements of the same group, thus favoring the elaboration of spectral averages. When analyzing the spectral standard of each group, the normal skin standard did not show a significant variation between the spectra; the standard of the pigmented nevi group showed significant variation, and the cutaneous melanoma group also showed variation. Through univariate analysis, specific bands were detected for each vibrational mode identified. The discriminatory analysis of the data showed a 75.3 percent efficiency of the differentiation between the three groups studied. CONCLUSION: The vibrational modes Polysaccharides, Tyrosine and Amide-I differentiated the melanoma from the pigmented nevus.


O melanoma cutâneo é o câncer de pele mais agressivo, e a espectroscopia FT-Raman tem sido estudada como um método em potencial que pode ser uma verdadeira alternativa no diagnóstico precoce de neoplasias. OBJETIVO: Qualificar os dados espectrais FT-Raman de modo a diferenciar melanoma cutâneo de nevo pigmentado. MÉTODOS: Foram utilizadas 10 amostras de melanoma cutâneo, obtidas por meio de biopsias incisionais realizadas "ex-vivo"; nove amostras de nevo pigmentado e 10 amostras de pele normal foram coletadas durante cirurgias plásticas. RESULTADOS: Os espectros FT-Raman de cada grupo diagnóstico apresentaram alta correlação entre os elementos do mesmo grupo, o que favoreceu a realização das médias espectrais. Analisando o padrão espectral de cada grupo, o de pele normal não mostrou grande variação entre os espectros; o de nevo pigmentado apresentou variação notável e, o grupo melanoma primário também indicou variação. Por meio de análise univariada foram identificadas bandas específicas para cada modo vibracional identificado. A análise discriminante aos dados mostrou 75,3 por cento de eficiência na diferenciação entre os três grupos estudados. CONCLUSÃO: Os modos vibracionais Polissacarídeos (Banda I), Tirosina (Banda 6) e Amida I (Banda 10) diferenciaram o melanoma do nevo pigmentado.


Subject(s)
Humans , Melanoma/pathology , Nevus, Pigmented/pathology , Skin Neoplasms/pathology , Analysis of Variance , Biopsy , Diagnosis, Differential , Spectroscopy, Fourier Transform Infrared/methods , Spectrum Analysis, Raman/methods
19.
Braz. j. pharm. sci ; 45(3): 423-428, July-Sept. 2009. ilus, graf
Article in English | LILACS | ID: lil-533168

ABSTRACT

Recently, there has been an interest in the use of shed snake skin as alternative model biomembrane for human stratum corneum. This research work presented as objective the qualitative characterization of alternative model biomembranes from Bothrops jararaca and Spilotis pullatus by FT-Raman, PAS-FTIR and DSC. The employed biophysical techniques permitted the characterization of the biomembranes from shed snake skin of B. jararaca and S. pullatus by the identification of vibrational frequencies and endothermic transitions that are similar to those of the human stratum corneum.


Existe atualmente interesse no uso da muda de pele de cobra como modelos alternativos de biomembranas da pele humana. O presente trabalho apresentou como objetivo a caracterização qualitativa de modelos alternativos de biomembranas provenientes de mudas de pele de cobra da Bothrops jararaca e Spilotis pullatus por espectroscopia Raman (FT-Raman), espectroscopia fotoacústica no infravermelho (PAS-FTIR) e calorimetria exploratória diferencial (DSC). As técnicas biofísicas FT-Raman, PAS-FTIR e DSC permitiram caracterizar qualitativamente os modelos alternativos de biomembranas provenientes das mudas de pele de cobra da B. jararaca e S. pullatus e identificar freqüências vibracionais e transições endotérmicas similares ao estrato córneo humano.


Subject(s)
Animals , Spectrum Analysis, Raman/methods , Bothrops , Membranes/chemistry , Skin Physiological Phenomena , Spectroscopy, Fourier Transform Infrared/methods , Snakes
20.
J. appl. oral sci ; 16(2): 145-149, Mar.-Apr. 2008. graf, tab
Article in English | LILACS | ID: lil-479761

ABSTRACT

Infrared spectroscopy is one of the most widely used techniques for measurement of conversion degree in dental composites. However, to obtain good quality spectra and quantitative analysis from spectral data, appropriate expertise and knowledge of the technique are mandatory. This paper presents important details to use infrared spectroscopy for determination of the conversion degree.


Subject(s)
Humans , Composite Resins/chemistry , Dental Materials/chemistry , Spectroscopy, Fourier Transform Infrared , Absorption , Algorithms , Calibration , Chemical Phenomena , Carbon/chemistry , Methacrylates/chemistry , Methylmethacrylate/chemistry , Optical Phenomena , Polymers/chemistry , Polymethyl Methacrylate/chemistry , Spectroscopy, Fourier Transform Infrared/methods , Spectroscopy, Fourier Transform Infrared/standards
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