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ABSTRACT Introduction: Acute paracetamol poisoning is confirmed by the determination of its serum level and allows assessing the risk of hepatotoxicity, which can be monitored by the Rumack-Matthew nomogram for the administration of the N-Acetylcysteine antidote, as well as for the prognosis of intoxication. Objective: Because of its analytical importance, we evaluated the influence of different matrices (ultrapure water, serum, and plasma) on the construction of the paracetamol calibration curve, aiming to reduce the analytical cost and facilitate its implementation in clinical and emergency laboratories. Material and methods: A standard stock solution of paracetamol of 1 mg ml-1 was obtained, from which appropriate dilutions originated the following concentrations 20, 50, 100, 150, 200, 250, and 300 mg l-1 in the different matrices, in triplicate, reading at complete after 430 nm in spectrophotometer and reproduced after three months. The results were statistically analyzed (p < 0.05). Results and discussion: Good laboratory practices include remaking the calibration curve when stock reagents are remade aiming to readjust the line equation indicated by a measuring instrument. The biological samples indicated as matrices on a calibration curve are usually serum and plasma. However, these biological products, when commercially purchased, are of high cost. Ultrapure water can replace serum and plasma in the paracetamol calibration curve according to the linearity of the curve, which showed the same trend line for the three matrices. Conclusion: The three matrices can be used in the construction of the paracetamol calibration curve, but the use of ultrapure water reduces the analysis costs.
RESUMEN Introducción: La intoxicación aguda por paracetamol se confirma mediante la determinación de su nivel sérico y permite evaluar el riesgo de hepatotoxicidad, que puede ser monitorizado mediante el nomograma de Rumack-Matthew para la administración del antídoto N-acetilcisteína, así como para el pronóstico de intoxicación. Objetivos: Por su importancia analítica, se evaluó la influencia de diferentes matrices (agua ultrapura, suero y plasma) en la construcción de la curva de calibración del paracetamol, con el objetivo de reducir el costo analítico y facilitar su implementación en laboratorios clínicos y de emergencia. Material y métodos: Se obtuvo una solución madre del estándar (stock) de paracetamol de 1 mg ml-1, de la cual se originaron diluciones adecuadas para obtener las siguientes concentraciones de 20, 50, 100, 150, 200, 250 y 300 mg l-1 con las diferentes matrices, por triplicado, con lectura a 430 nm en epectrofotômetro, reproduciéndose a los tres meses. Los resultados se analizaron estadísticamente (p < 0,05). Resultados y discusión: Las buenas prácticas de laboratorio incluyen rehacer la curva de calibración cuando se rehacen los reactivos del estándar con el fin de reajustar la ecuación lineal indicada por un instrumento de medición. Las muestras biológicas indicadas como matrices en una curva de calibración suelen ser suero y plasma. Sin embargo, estos productos biológicos cuando se compran comercialmente son de alto costo. El agua ultrapura puede reemplazar el suero y el plasma en la curva de calibración de paracetamol de acuerdo con la linealidad de la curva, que mostró la misma línea de tendencia para las tres matrices. Conclusión: Las tres matrices pueden usarse en la construcción de la curva de calibración de paracetamol, pero el uso de agua ultrapura reduce los costos de análisis.
RESUMO Introdução: A intoxicação aguda pelo paracetamol é confirmada pela determinação de seu nível sérico e permite avaliar o risco de hepatotoxicidade, que pode ser monitorado pelo nomograma Rumack-Matthew para a administração do antídoto N-acetilcisteína, bem como para o prognóstico da intoxicação. Objetivos: Diante de sua importância analítica, avaliamos a influência de diferentes matrizes (água ultrapura, soro e plasma) na construção da curva de calibração do paracetamol, visando diminuir o custo analítico e facilitar a sua implantação em laboratórios clínicos e de urgência. Material e métodos: Obtivemos uma solução estoque padrão de paracetamol de 1 mg ml-1, da qual originaram diluições apropriadas para se obter as concentrações de 20, 50, 100, 150, 200, 250 e 300 mg l-1 com as diferentes matrizes, em triplicata, com leituras em espectrofotômetro a 430 nm, sendo reproduzidas após três meses. Os resultados foram analisados estatisticamente (p < 0,05). Resultados e discussão: Nas boas práticas de laboratório, inclui-se o refazimento da curva de calibração quando os reagentes estoques são refeitos visando ao reajuste da equação de reta indicado por um instrumento de medição. As amostras biológicas indicadas como matrizes em uma curva de calibração são, usualmente, soro e plasma. Porém, esses produtos biológicos quando adquiridos comercialmente são de custo elevado. A água ultrapura pode substituir soro e plasma na curva de calibração do paracetamol em função da linearidade da curva, a qual mostrou a mesma linha de tendência para as três matrizes. Conclusão: As três matrizes podem ser utilizadas na construção da curva de calibração do paracetamol, mas o uso de água ultrapura diminui os custos da análise.
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A highly sensitive and selective method was developed for both UV-vis spectrophotometric and fluo-rimetric determination of organophosphorus pesticides(OPs).This method used silver nanoparticles(AgNPs)modified with graphitic carbon nitride(g-C3N4).The AgNPs reduced the fluorescence intensity of g-C3N4.Acetylthiocholine(ATCh)could be catalytically hydrolyzed by acetylcholinesterase(AChE)to form thiocholine,which induces aggregation of the AgNPs.This aggregation led to the recovery of the blue fluorescence of g-C3N4,with excitation/emission peaks at 310/460 nm.This fluorescence intensity could be reduced again in the presence of OPs because of the inhibitory effect of OPs on the activity of AChE.The degree of reduction was found to be proportional to the concentration of OPs,and the limit of fluorometric detection was 0.0324 μg/L(S/N = 3).In addition,the absorption of the g-C3N4/AgNPs at 390 nm decreased because of the aggregation of the AgNPs,but was recovered in presence of OPs because of the inhibition of enzyme activity by OPs.This method was successfully applied to the analysis of parathion-methyl in real samples.
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Objective To establish a method for content determination of total flavones and polysaccharides in Fangshu Qingre mixture by UV-Vis Spectrophotometry. Methods The contents of total flavones and polysaccharides in Fangshu Qingre mixture were determined by UV-Vis spectroscopy with rutin and anhydrous glucose as reference substance, and the wavelength was set at 508 nm and 487 nm. Results The contents were from 0.00 to 59.20 μg/ml for total flavones and from 10.92 to 109.20 μg/ml for total polysaccharides in Fangshu Qingre mixture. The recoveries of total flavones and total polysaccharides were 104.4% and 104.8% respectively. Conclusion The method of using ultraviolet spectroscopy was simple, reproducible, accurate and reliable, which could be preferably used as the method for content determination of total flavones and polysaccharides in Fangshu Qingre mixture.
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In this study, methods based on UV-Vis spectrophotometry (Sandell-Kolthoff reaction) and inductively coupled plasma optical emission spectrometry (ICP OES) were developed in order to determine iodine in pharmaceuticals. A simple preparation of samples, which consisted in the solubilization by means of ultrasound, was performed using pure water as solvent. The developed analytical methods were validated employing limit of detection, precision and accuracy. The recovery range is 101.0% - 104.0% for the expectorant solutions, and 98.0% - 102.0% for the supplements using the ICP OES technique. For the UV-Vis spectrophotometric method, the recovery range is 96.0% - 98.0% for the expectorant solutions, and 96.0% - 98.3% for the supplements. These methods are simple and accessible, and might be used in the pharmaceutical field.
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Aims: This study was undertaken to compare the quality and efficacy of six brands of antibacterial discs that are commercially available in Nigeria. Methodology: The brands evaluated include two foreign brands (Oxoid and Abtek) and four local brands (Optudisc, Polydisc, Maxidisc and Jirehdisk). The brands were analyzed by antibiotic susceptibility testing (AST) using laboratory isolates of Staphylococcus aureus and Escherichia coli to measure the antimicrobial performances of the brands; and UV-Vis spectrophotometry to measure the absorbances of antibiotics extracted from antibiotic discs of the various brands. Results: All of the brands of antibacterial discs of under study exhibited variations in their antimicrobial performances and UV-absorbances. This was observed where some of the discs with lower stated potencies produced inhibition zones and absorbances far greater than similar discs from other brands with higher stated potencies. Also, discs of the same stated potencies showed variable results in both the antibiotic susceptibility testing (AST) and UV-Vis spectrophotometric analyses. Coefficients of variation greater than 5%, which indicates high disc-to-disc variation and unsatisfactory reproducibility, were recorded highest among the local brands during the AST. All the brands with multidisc panels, except the Abtek and Polydisc brands, produced some zones of inhibition that are unreadable. Of all the zones of inhibition that were unreadable, Optudisc brand recorded the highest rate (36·7%), while 6·7% of discs of Jirehdisk brand and 6·7% of discs of Maxidisc brand produced inhibition zones that were unreadable. Conclusion: All brands of susceptibility discs evaluated in this study except the Oxoid and Abtek brands manifested poor quality and performed below expected standard, though one of the local brands (Polydisc) performed closest to the foreign brands. With further improvement in quality, these brands may be recommended for use in Nigeria.
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Objective: To express a cost efficacious and environment friendly method for the green synthesis of silver nanoparticles (AgNPs) from Catharanthus roseus var. alba (C. roseus var. alba) callus extract. Methodology: The aqueous solution of sliver nitrate containing Ag+ ions (1 mM) are integrating 100 μL of aqueous extract of callus of C. roseus var. alba and 10 mL of 1% w/v aqueous solution of polyethylene glycol 4000 to 90 mL. This was then alkalized with 0.1 NaOH (20 μL) and treated in a microwave oven (800 W) for 40 sec for the reduction of metal ion and the reaction takes place at room temperature (250C). The reduction of the Ag+ ions by aqueous callus extract of C. roseus var. alba in the solutions was monitored by UV–Visible spectrum and further characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and x-ray diffraction (XRD). Antibacterial activity was assessed on bacterial strain of Staphylococcus aureus and Pseudomonas aeruginosa (S. aureus and P. aeruginosa) by using the disc-diffusion assay method. Results: Characterization of AgNPs was done DLS, TEM and XRD methods. The Dynamic Light Scattering (DLS) showed the particle size distribution of the AgNPs synthesized from C. roseus var. alba callus extract was found 86.95 nm with polydispersity index (PDI) value of = 0.304. TEM images showed the formation of AgNPs with an average size of 10 nm to 20 nm. And the XRD analysis showed that the AgNPs were crystalline in nature with face-centered-cubic (FCC). For the assessment of antibacterial activity the concentration of AgNPs 25 μL, 50 μL, 100 μL and 150 μL were used against both the bacterial strain S. aureus and P. aeruginosa, the zone of inhibition found 4 mm, 7 mm, 16 mm and 23 mm as well as 5 mm, 9 mm, 19 mm and 26 mm respectively. Conclusions: Aseptically engendered callus of C. roseus var. alba demonstrates vigorous potential for synthesis of silver nanoparticles by rapid reduction of Ag+ to Ag. The biologically synthesized AgNPs showed more preponderant antibacterial effect against S. aureus and P. aeruginosa.
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En este trabajo se propone y se valida una metodología analítica por espectrofotometría UV aplicada al estudio de la solubilidad de algunas sulfonamidas en mezclas cosolventes. Los parámetros evaluados fueron: especificidad, linealidad, precisión y límites de detección y cuantificación, así como la estabilidad de los fármacos bajos las condiciones de análisis de solubilidad. El método propuesto es útil para determinar la solubilidad de estas sulfonamidas en función de la temperatura y la composición cosolvente.
An analytical method by UV-spectrophotometry has been proposed and validated to study the solubility of some sulfonamides in cosolvent mixtures. The parameters evaluated were specificity, linearity, precision, and detection and quantification limits, as well as the drug stability under the solubility analysis conditions. The developed method was useful to determine the solubility of these drugs as a function of temperature and cosolvent concentration.
Neste trabalho propomos é validamos uma metodologia analítica ultravioleta para o estudo da solubilidade de alguns sulfamidas em misturas dos solventes. Os parâmetros avaliados foram: especificidade, linearidade, precisão, exatidão e limites de detecção e quantificação, e a estabilidade dos fármacos nas condições de estúdio. O método proposto é útil para a determinação da solubilidade destes sulfamidas em função da temperatura e da composição do cosolvente.
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En este trabajo se propone y se valida una metodología analítica por espectrofotometría UV aplicada al estudio de la solubilidad de algunas sulfonamidas en mezclas cosolventes. Los parámetros evaluados fueron: especificidad, linealidad, precisión y límites de detección y cuantificación, así como la estabilidad de los fármacos bajos las condiciones de análisis de solubilidad. El método propuesto es útil para determinar la solubilidad de estas sulfonamidas en función de la temperatura y la composición cosolvente.
An analytical method by UV-spectrophotometry has been proposed and validated to study the solubility of some sulfonamides in cosolvent mixtures. The parameters evaluated were specificity, linearity, precision, and detection and quantification limits, as well as the drug stability under the solubility analysis conditions. The developed method was useful to determine the solubility of these drugs as a function of temperature and cosolvent concentration.
Neste trabalho propomos é validamos uma metodologia analítica ultravioleta para o estudo da solubilidade de alguns sulfamidas em misturas dos solventes. Os parâmetros avaliados foram: especificidade, linearidade, precisão, exatidão e limites de detecção e quantificação, e a estabilidade dos fármacos nas condições de estúdio. O método proposto é útil para a determinação da solubilidade destes sulfamidas em função da temperatura e da composição do cosolvente.
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OBJECTIVE: To prepare and in vitro evaluate the shell vaginal ring(VR)containing mifepristone. METHODS: The solid dispersion of mifepristone with PVPK30 as a carrier was prepared and characterized by the methods of differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD). The shell vaginal ring containing mifepristone was prepared by the method of mold molding process, the inner layer of vaginal ring is the blank silastic skeleton, the middle layer of vaginal ring is the part containing drug, the outermost layer is a non-active silicon rubber membrane. In vitro drug release test was conducted in a dissolution apparatus, release medium was 200 mL PBS (pH 4.0) meeting with sink conditions, and release samples were determined by the UV-vis spectrophotometry. RESULTS: The shell vaginal ring containing mifepristone had a steady drug release rate in vitro during 21 d. The daily release of mifeprisotne was about 1 mg, which sustained two weeks at least at this release rate, and the variance intra- batch was very small. CONCLUSION: The shell vaginal ring containing mifepristone exhibits the sustained and controlled release characteristics in vitro, and the preparation method is stable. The developed UV-vis method is rapid, accurate and convenient.
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Este artigo descreve o desenvolvimento e a validação de método espectrofotométrico UV-Visível para quantificação de derivados do ácido o-hidroxicinâmico em folhas de Echinodorus grandiflorus. O método demonstrou ser linear (r² = 0,9974), preciso (DPR < 15%) na análise de matriz complexa e exata (recuperação = 107,56%).
This paper describes the development and the validation of an UV-Vis spectrophotometric method for the quantification of derivatives of o-hydroxycinnamic acid in leaves of Echinodorus grandiflorus. The method showed to be linear (r² = 0.9974), precise (RSD < 15%) in the analysis of complex matrix and accurate (recovery = 107.56%).
Subject(s)
Coumaric Acids/analysis , Validation Study , Methodology as a Subject , Quality Control , Spectrophotometry, Ultraviolet/methods , Alismataceae/metabolismABSTRACT
Triamcinolone (TRI), a drug widely used in the treatment of ocular inflammatory diseases, is practically insoluble in water, which limits its use in eye drops. Cyclodextrins (CDs) have been used to increase the solubility or dissolution rate of drugs. The purpose of the present study was to validate a UV-Vis spectrophotometric method for quantitative analysis of TRI in inclusion complexes with beta-cyclodextrin (B-CD) associated with triethanolamine (TEA) (ternary complex). The proposed analytical method was validated with respect to the parameters established by the Brazilian regulatory National Agency of Sanitary Monitoring ANVISA). The analytical measurements of absorbance were made at 242nm, at room temperature, in a 1-cm path-length cuvette. The precision and accuracy studies were performed at five concentration levels (4, 8, 12, 18 and 20µg.mL-1. The B-CD associated with TEA did not provoke any alteration in the photochemical behavior of TRI. The results for the measured analytical parameters showed the success of the method. The standard curve was linear (r2 > 0.999) in the concentration range from 2 to 24 µg.mL-1. The method achieved good precision levels in the inter-day (relative standard deviation-RSD <3.4%) and reproducibility (RSD <3.8%) tests. The accuracy was about 80% and the pH changes introduced in the robustness study did not reveal any relevant interference at any of the studied concentrations. The experimental results demonstrate a simple, rapid and affordable UV-Vis spectrophotometric method that could be applied to the quantitation of TRI in this ternary complex.
A triancinolona (TRI) é um fármaco amplamente utilizado no tratamento de doenças inflamatórias do globo ocular e é praticamente insolúvel em água, o que limita sua utilização na forma de colírio. As ciclodextrinas (CDs) têm sido utilizadas com sucesso para aumentar a solubilidade ou velocidade de dissolução de fármacos. O presente estudo teve como objetivo a validação de uma metodologia analítica para a TRI a partir de complexos de inclusão com beta-ciclodextrina (B-CD) associada com a trietanolamina (TEA) (complexo ternário) por espectrofotometria de UV-Vis. A validação do método proposto foi realizada de acordo com os parâmetros analíticos estabelecidos pela Agência Nacional de Vigilância Sanitária (ANVISA). As análises quantitativas foram realizadas a 242nm a temperatura ambiente, utilizando cubeta de quartzo de 1cm. Os estudos de precisão e exatidão foram realizados para cinco níveis de concentração (4, 8, 12, 18 e 20µg.mL-1). A B-CD associada a TEA não alterou o comportamento fotoquímico da TRI. Os resultados da avaliação dos parâmetros analíticos demonstraram o sucesso da metodologia. A curva padrão apresentou linearidade (r2 > 0.999) na faixa de concentração de 2 a 24µg.mL-1. A metodologia apresentou bons níveis de precisão para o estudo inter dia (desvio padrão relativo-DPR <3.4%) e reprodutibilidade (DPR<3.8%). A exatidão ficou em torno de 80% e a variação de pH inserida no estudo de robustez não revelou uma interferência significativa em todas as concentrações estudadas. Os resultados experimentais demonstraram um simples, rápido e viável método de espectrofotometria de UV-Vis com aplicabilidade para a análise quantitativa da TRI a partir do complexo ternário.