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Braz. J. Pharm. Sci. (Online) ; 53(1): e15181, 2017. tab, graf
Article in English | LILACS | ID: biblio-839459


Sildenafil citrate (SILC) is a potent phosphodiesterase-5 inhibitor used for erectile dysfunction and pulmonary hypertension. This study shows two simple, fast and alternative analytical methods for SILC determination by non-aqueous titration and by derivative ultraviolet spectrophotometry (DUS) in active pharmaceutical ingredient and/or dosage forms. The quantitation method of SILC active pharmaceutical ingredient by non-aqueous acid-base titration was developed using methanol as solvent and 0.1 mol/L of perchloric acid in acetic acid as titrant. The endpoint was potentiometrically detected. The non-aqueous titration method shows satisfactory repeatability and intermediate precision (RSD 0.70-1.09%). The neutralization reaction occurred in the stoichiometric ratio 1:1 in methanol. The determination of SILC active pharmaceutical ingredient or dosage forms by DUS was developed in the linear range from 10 to 40 µg/mL, in 0.01 mol/L HCl, using the first order zero-peak method at λ 256 nm. The DUS method shows selectivity toward tablets excipients, appropriate linearity (R2 0.9996), trueness (recovery range 98.86-99.30%), repeatability and intermediate precision in three concentration levels (RSD 1.17-1.28%; 1.29-1.71%, respectively). Therefore, the methods developed are excellent alternatives to sophisticated instrumental methods and can be easily applied in any pharmaceutical laboratory routine due to simple and fast executions.

Spectrophotometry, Ultraviolet/methods , Titrimetry/methods , Sildenafil Citrate/analysis , Tablets/pharmacology , Vasodilator Agents/classification
Rev. cuba. farm ; 50(1)ene.-mar. 2016. ilus, graf, tab
Article in Spanish | LILACS, CUMED | ID: biblio-844862


Introducción: la colchicina es una alternativa terapéutica indicada por vía oral para las crisis agudas de la gota. Se formula en tabletas de baja dosificación debido a su elevada toxicidad. Los Laboratorios Dr.A. Bjarner C.A producen las tabletas de Artrichine y se requiere de un método sencillo, pero a la vez confiable para realizar el control de calidad de este producto terminado, que considere la solubilidad en etanol, la presencia de cromóforos y la composición de la formulación de la colchicina. Objetivo: se propuso validar un método por espectrofotomería UV útil para el control de rutina. Métodos: se aplicó un método simple, que se modifica del método establecido en la Farmacopea Británica del 2009 para las tabletas, por espectrofotometría UV directa. Se basa en la extracción del analito en etanol absoluto y su posterior determinación a 350 nm. La validación del método se realizó a través de los parámetros linealidad, precisión, exactitud y especificidad frente a los componentes de la formulación. Resultados: se estableció una metodología analítica muy sencilla para obtener una solución transparente a partir de la forma terminada, de igual concentración a la solución de referencia. El cumplimiento satisfactorio de todos los criterios de aceptación establecidos para los parámetros evaluados permitió demostrar la validez del método en estudio para el control de calidad en el rango de 50 a 150 por ciento (5-15 µg/mL). Conclusiones: el método por espectrofotometría UV resultó específico, lineal, exacto y preciso para su aplicación al control de calidad de la colchicina en Artrichine tabletas(AU)

Introduction: colchicine is a therapeutic alternative orally prescribed for acute gout. It is formulated as low dose tables due to its high toxicity. Dr A. Bjarner C.A laboratories manufacture Artrichine tablets and it requires a simple and reliable method to conduct quality control of the finished product that will consider ethanol-soluble characteristics, presence of chromophores and composition of colchicine formulation. Objective: to validate an ultraviolet spectrophotometry-based method for the routine quality control. Methods: a simple method by direct UV spectrophotometry which is modified from the set method of the British Pharmacopeia 2009 for tablets. It is based on the analyte extraction in absolute ethanol and the estimation at 350 nm. The method was validated on account of linearity, precision, accuracy and specificity against the formulation components. Results: a very simple analytical methodology was established to obtain a transparent solution from the finished form, with the same concentration as that of the reference solution. The satisfactory compliance with all the acceptance criteria for the evaluated parameters allowed proving the validity of the study method for the quality control in the 50 to 150 percent range (5-15 ug/ml). Conclusions: the UV spectrophotometry-based method proved to be specific, linear, accurate and precise for the quality control of colchicine in Artrichine tablets(AU)

Humans , Colchicine/therapeutic use , Reference Drugs , Validation Studies as Topic , Gout/therapy , Spectrophotometry, Ultraviolet/methods
Braz. j. pharm. sci ; 52(2): 251-264, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-794999


ABSTRACT This study aimed to obtain and characterize a microemulsion (ME) containing phenobarbital (PB). The PB was incorporated in the proportion of 5% and 10% in a microemulsion system containing Labrasol(r), ethanol, isopropyl myristate and purified water. The physicochemical characterization was performed and the primary stability of the ME was evaluated. An analytical method was developed using spectrophotometry in UV  = 242 nm. The kinetics of the in vitro release (Franz model) of the ME and the emulsion (EM) containing PB was evaluated. The incorporation of PB into ME at concentrations of 5 and 10% did not change pH and resistance to centrifugation. There was an increase in particle size, a decrease of conductivity and a change in the refractive index in relation to placebo ME. The ME remained stable in preliminary stability tests. The analytical method proved to be specific, linear, precise, accurate and robust. Regarding the kinetics of the in vitro release, ME obtained an in vitro release profile greater than the EM containing PB. Thus, the obtained ME has a potential for future transdermal application, being able to compose a drug delivery system for the treatment of epilepsy.

RESUMO O objetivo deste trabalho foi obter e caracterizar uma microemulsão (ME) contendo fenobarbital (FEN). O FEN foi incorporado na proporção de 5% e 10% em um sistema microemulsionado composto por labrasol(r), etanol, miristato de isopropila e água purificada. Foi realizada a caracterização físico-química e avaliada a estabilidade preliminar da ME. Desenvolveu-se um método analítico por espectrofotometria em UV  = 242 nm. Foi avaliada a cinética de liberação in vitro (em modelo de Franz) da ME e da emulsão (EM) contendo FEN. A incorporação do FEN em ME nas concentrações de 5 e 10% não alterou o pH e a resistência à centrifugação. Houve aumento do tamanho da partícula, redução da condutividade e alteração do índice de refração em relação à ME placebo. A ME manteve-se estável nos ensaios de estabilidade preliminar. O método analítico demonstrou ser específico, linear, preciso, exato e robusto. Na cinética de liberação in vitro, a ME obteve um perfil de liberação in vitro superior a EM contendo FEN. Desta forma, a ME obtida tem potencial para uma futura aplicação transdérmica, podendo compor um sistema de liberação de fármacos para tratamento da epilepsia.

Phenobarbital/pharmacokinetics , Emulsions/analysis , Quality Control , Spectrophotometry, Ultraviolet/methods , Kinetics , Nanotechnology/methods , Drug Liberation/drug effects
Braz. j. pharm. sci ; 51(1): 183-191, Jan-Mar/2015. tab, graf
Article in English | LILACS | ID: lil-751370


The aim of this study was to develop and validate a UV spectrophotometric method for determination of LPSF/AC04 from inclusion complex and encapsulated into liposomes. The validation parameters were determined according to the International Conference on Harmonisation (ICH) and National Health Surveillance Agency (ANVISA) guidelines. LPSF/AC04 was determined at 250 nm in methanol by a UV spectrophotometric method, exhibiting linearity in the range from 0.3 to 2 µg.mL−1 (Absorbance=0.18068 x [LPSF/AC04 µg.mL-1] + 0.00348), (r2=0.9995). The limits of detection and quantification were 0.047µg.mL−1 and 0.143µg.mL−1, respectively. The method was accurate, precise, reproducible and robust since all the samples analyzed had coefficient of variation of less than 5% and no statistically significant difference between theoretical and practical concentrations was detected. Thus, a rapid, simple, low cost and sensitive spectrophotometric method was developed and validated for determining the content of inclusion complex and liposomes containing LPSF/AC04.

O objetivo deste estudo foi desenvolver e validar um método espectrofotométrico para determinação do LPSF/AC04 em complexo de inclusão e encapsulado em lipossomas. Os parâmetros de validação foram determinados de acordo com o International Conference on Harmonisation (ICH) e Agência Nacional de Vigilância Sanitária (ANVISA). OLPSF/AC04 foi determinado a 250 nm em metanol pelo método espectrofotométrico UV, que apresenta linearidade na faixa de 0,3 a 2 µg/mL (Absorbância = 0,18068 x [LPSF/AC04 µg/mL] + 0,00348), (r2 = 0,9995). Os limites de detecção e quantificação foi 0,047 µg/mL e 0,143 µg/mL, respectivamente. O método foi exato, preciso, reprodutível e robusto e todas as amostras analisadas apresentaram coeficiente de variação menor que 5% e não houve diferença estatisticamente significante entre a concentração teórica e a prática. Assim, um método espectrofotométrico rápido, simples, sensível e de baixo custo foi desenvolvido e validado para determinar o conteúdo do LPSF/AC04 em complexos de inclusão e encapsulados em lipossomas.

Spectrophotometry, Ultraviolet/methods , Validation Study , Liposomes/pharmacokinetics , /analysis
Indian J Exp Biol ; 2014 Nov; 52(11): 1071-1081
Article in English | IMSEAR | ID: sea-153790


Most of the phenol compounds are toxic and have been considered as hazardous pollutants. Several physicochemical and biological methods are available to detect and monitor the phenol pollutants in water and soil. In the present study, phenol constituents of winery, paper and plastic industrial effluents were successfully detected employing tyrosinase-gold nanoparticles bioconjugate. The synthesis of extracellular tyrosinase and gold nanoparticles was achieved by a single isolate of Streptomyces sp. DBZ-39. Enhanced production (369.41 IU) of tyrosinase was produced in submerged bioprocess employing response surface method with central composite design. Extracellular gold nanoparticles synthesized (12-18 nm) by Streptomyces sp. DBZ-39 were characterized with TEM, EDAX and FTIR analysis. A rapid detection (within 10 min) of phenol constituents from winery effluents was achieved by bioconjugate, when compared to tyrosinases and gold nanoparticles independently. Streptomyces tyrosinase could exhibit relatively a better performance than commercially available mushroom tyrosinase in the detection of phenol constituents. Winery effluent has shown much higher content (0.98 O.D) of phenol constituents than paper and plastic effluents based on the intensity of color and U.V absorption spectra.

Agaricales/enzymology , Biosensing Techniques , Colorimetry/methods , Culture Media/pharmacology , Environmental Pollutants/analysis , Ferrocyanides , Fungal Proteins/isolation & purification , Fungal Proteins/metabolism , Gold , Industrial Waste/analysis , Monophenol Monooxygenase/isolation & purification , Monophenol Monooxygenase/metabolism , Mycology/methods , Nanoparticles , Paper , Phenols/analysis , Plastics , Soil Microbiology , Species Specificity , Spectrophotometry, Ultraviolet/methods , /enzymology , /growth & development , /isolation & purification , Tyrosine/metabolism , Wine
Rev. cuba. farm ; 48(2)abr.-jun. 2014. Ilus, tab
Article in Spanish | LILACS, CUMED | ID: lil-731955


INTRODUCCCIÓN: las quinolonas son un grupo de agentes antimicrobianos de gran importancia en la clínica. El clorhidrato de ciprofloxacina monohidrato es una fluoroquinolona antibacterial de segunda generación que se indica en el tratamiento de diversas infecciones y se comercializa en forma de colirio, inyectable, cápsulas y tabletas. OBJETIVO: desarrollar y validar un método analítico por espectrofotometría ultravioleta, con vistas a su aplicación al control de calidad del clorhidrato de ciprofloxacina en tabletas Ciprecu recién elaboradas. MÉTODOS: se desarrolló el método en el laboratorio y se realizó una validación exhaustiva atendiendo a los parámetros de la categoría I. El método se seleccionó teniendo en cuenta la presencia de grupos cromóforos en la estructura del compuesto analizado. Se determinó la longitud de onda de máxima absorción a 273 nm de 5 µg/mL en ácido clorhídrico 0,1 mol/L. RESULTADOS: a partir del proceso de validación realizado, se demostró la adecuada especificidad frente a los componentes de la matriz en estudio, así como su linealidad, exactitud y precisión en el rango de 2,5 a 7,5 µg/mL. Los resultados de la aplicación de este método fueron similares a los obtenidos por el método oficial propuesto con iguales propósitos en USP 33, 2010. CONCLUSIONES: el método fue válido con el objetivo propuesto, lo cual constituye una nueva alternativa simple, rápida y económica para el control de calidad de clorhidrato de ciprofloxacina en tabletas Ciprecu(AU)

INTRODUCTION: quinolones are a group of antimicrobials of high clinical significance. Ciprofloxacin hydrochloride monohydrate is a second-generation antibacterial fluoroquinolone for treatment of several infections and is marketed as eye drops, injections, capsule and tablets. OBJECTIVE: to develop and to validate an ultraviolet spectrophotometric analytical method to be used in the quality control of ciprofloxacin hydrochloride monohydrate in newly manufactured Ciprecu tablets. METHODS: this method was devised at the laboratory and thoroughly validated pursuant to the category I parameters. The method was selected on account of the existence of chromophore groups in the structure of the analyzed compound. The maximum absorption wavelength was set at 273 nm of 5 µg/mL in 0.1 mol/L hydrochloric acid. RESULTS: based on the validation process, it was demonstrated that this method has adequate specificity against the study matrix components, as well as its linearity, accuracy and precision in the range of 2.5 to 7.5 µg/mL. The results of the application of this method were similar to those of the official procedure suggested for the same purposes in USP 33, 2010. CONCLUSIONS: The analytical method was valid for the suggested purposes, so it is a new simple, rapid and economic alternative for the quality control of Ciprofloxacin hydrochloride in Ciprecu tablets(AU)

Humans , Quality Control , Spectrophotometry, Ultraviolet/methods , Ciprofloxacin/therapeutic use , Tablets , Validation Studies as Topic
Braz. j. pharm. sci ; 50(1): 137-146, Jan-Mar/2014. tab, graf
Article in English | LILACS | ID: lil-709546


We compared the impregnation techniques for globules according to the Manual of Technical Norms for Homeopathic Pharmacies (MNTFH) of the Association of Homeopathic Pharmacists (ABFH), Brazilian Homeopathic Pharmacopoeia (FHB) and variations of these techniques. The variables were evaluated in this procedure, three different sizes of globules (N o . 3, 5 and 7), the hydroalcoholic solution of 70% (v/v) Minoxidil 2% (w/v) was used to impregnate the globules in concentrations of 2, 3, 4, 5% (v/w) and the impregnation at 10 %(v/w) was used hydroalcoholic solutions at 70, 80 and 90% (v/v), and four impregnation techniques various ( A -glass, B -paper, C -cup and D -FHB). As the results of content uniformity did not demonstrate a normal distribution, the one way ANOVA and a nonparametric statistical model were used for evaluation. Considering the average, the standard deviation (SD), the individual variance of each group and the principal components analysis graphs (PCA), it was observed that the “A” impregnation of globules technique, with 5% (v/w) of the impregnation concentrations and the No.5 globule presented the best uniformity of dose. As to the drying, there was a need to use a heat source.

Compararam-se as técnicas de impregnação para glóbulos segundo o Manual de Normas Técnicas para Farmácias Homeopáticas (MNTFH) da Associação Brasileira de Farmacêuticos Homeopatas (ABFH), Farmacopeia Homeopática Brasileira (FHB) e variações destas técnicas. As variáveis avaliadas neste processo foram: três tamanhos diferentes de glóbulos (n.º 3, 5 e 7); a solução hidroalcóolica a 70% (v/v) de minoxidil a 2% (p/v) foi utilizada para impregnar os glóbulos nas concentrações de 2, 3, 4, 5% (v/p) e na impregnação a 10% (v/p) utilizaram-se as soluções hidroalcóolicas a 70, 80 e 90% (v/v); e quatro técnicas de impregnação diferentes ( A -vidro, B -papel, C -copo e D -FHB). A impregnação foi validada através da uniformidade de dose por conteúdo, sendo o minoxidil a substância quantificada. Como os resultados da uniformidade de dose por conteúdo não demonstraram distribuição normal, utilizaram-se o One way ANOVA e um modelo estatístico não paramétrico para sua avaliação. Considerando-se a média, o desvio padrão (DP), a variância individual de cada grupo e os gráficos de análise de componentes principais (ACP), observou-se que a impregnação que utilizou o glóbulo nº5, a concentração para impregnação de 5% (v/p), graduação alcoólica de 70% (v/v) e técnica “A” apresentou a melhor uniformidade de dose. Quanto à secagem, verificou-se a necessidade do uso de uma fonte de calor.

Spectrophotometry, Ultraviolet/methods , Homeopathic Vehicles , Globules , Analysis of Variance
Braz. j. pharm. sci ; 50(1): 83-89, Jan-Mar/2014. tab, graf
Article in English | LILACS | ID: lil-709549


Ranitidine is an antisecretory drug with H2 antagonist action useful in treating gastric and duodenal disorders. The dissolution test is used to obtain and compare dissolution profiles and establish similarities of pharmaceutical forms. The aim of this study was to compare the dissolution profiles of 150-mg coated ranitidine tablets of a reference drug (product A) and a generic (product B) and a similar (product C) drug marketed in Bahia, Brazil using a simple, fast and inexpensive ultraviolet method. Dissolution was determined using a USP type 2 apparatus at 50 rpm with 900 mL of distilled water at 37.0 ± 0.5 oC for 1h. The dissolution test was performed in compliance with the American Pharmacopoeia (USP-32). Dissolution efficiency and difference (f1) and similarity (f2) factors were calculated and evaluated. The proposed quantification methodology for drug dissolution test was validated, presenting accuracy, linearity and precision within the acceptance criteria. Products A, B and C showed dissolution efficiency values of 59.29, 73.59 and 66.67%, respectively. Factors f1 and f2 were calculated and showed that the profiles of products A, B and C were dissimilar. However, all the products released ranitidine satisfactorily, with at least 80% of the drug dissolved within 30 min.

A ranitidina é um fármaco antissecretor, antagonista H2, usado no tratamento de desordens gástricas e duodenais. O teste de dissolução é utilizado para obter e comparar perfis de dissolução, estabelecendo semelhança de formas farmacêuticas. Este estudo tem por objetivo comparar perfis de dissolução de comprimidos revestidos contendo 150 mg de ranitidina, em medicamentos de referência (produto A), genérico (produto B) e similar (produto C) comercializados na Bahia-Brasil, usando um método ultravioleta simples, rápido e de baixo custo. As condições que permitiram a determinação da dissolução foram: aparelho USP tipo 2 a 50 rpm, contendo 900 mL de água destilada mantida a 37,0 ± 0,5 °C, durante 1 h. O teste de dissolução foi realizado em conformidade com a Farmacopeia Americana (USP-32). Cálculo da eficiência de dissolução e fatores de diferença (f1) e semelhança (f2) foram avaliados. A metodologia proposta para a quantificação do fármaco no ensaio de dissolução foi validada apresentando precisão, linearidade e exatidão dentro dos critérios de aceitação. Os produtos A, B e C mostraram eficiência de dissolução de 59,29, 73,59 e 66,67%, respectivamente. Calcularam-se os fatores f1 e f2 e mostrou-se que os perfis não foram semelhantes para os comprimidos de produtos A, B e C. No entanto, todos os produtos liberaram o fármaco satisfatoriamente, pois, pelo menos, 80% de ranitidina foram dissolvidos em 30 min.

Ranitidine/pharmacokinetics , Tablets, Enteric-Coated/pharmacokinetics , Spectrophotometry, Ultraviolet/methods , Tablets/pharmacokinetics , Brazil , Dissolution/analysis
Braz. j. pharm. sci ; 50(3): 457-465, Jul-Sep/2014. tab, graf
Article in English | LILACS | ID: lil-728704


New, simple and cost effective UV-spectrophotometric method was developed for the estimation of orbifloxacin in pharmaceutical formulation. Orbifloxacin was estimated at 290 nm in 0.5 M hydrochloric acid. Linearity range was found to be 1.0-6.0 μg mL-1. The method was tested and validated for various parameters according to main guidelines. The proposed method was successfully applied for the determination of orbifloxacin in tablets. The results demonstrated that the procedure is accurate, precise and reproducible, while being simple, economical and less time consuming. It can be suitably applied for the estimation of orbifloxacin in routine quality control and dissolution studies.

Um método espectrofotométrico novo, simples e de baixo custo foi desenvolvido para a determinação de orbifloxacino em formulação farmacêutica. O orbifloxacino foi determinado em 290 nm utilizando ácido clorídrico 0,5 M como solvente. O intervalo de linearidade usado foi de 1,0 a 6,0 μg mL-1. O método foi testado e validado em vários parâmetros de acordo com os principais guias. O método proposto foi aplicado com sucesso para a determinação de orbifloxacino em comprimidos. Os resultados demonstraram que este procedimento é exato, preciso e reprodutível, ao mesmo tempo em que é simples, barato e de mais rápida execução e pode ser adequadamente aplicado para a determinação de orbifloxacino na rotina do controle de qualidade e em estudos de dissolução de comprimidos contendo este fármaco.

Spectrophotometry, Ultraviolet/methods , Validation Study , Anti-Bacterial Agents/analysis , Chemistry, Pharmaceutical , Dissolution
Article in Portuguese | LILACS | ID: lil-658490


Este trabalho teve como objetivo desenvolver e validar metodologia analítica por espectrofotometria no UV para a quantificação de flavonóides totais, expressos em vitexina, em cápsulas contendo extrato seco de Passiflora incarnata L. O método foi desenvolvido a partir da metodologia de doseamento de flavonóides totais descrita na monografia do extrato seco de P. incarnata L, disponível na Farmacopeia Britânica (2010). A validação da metodologia analítica de doseamento foi realizada de acordo com a Anvisa RE N° 899/2003 e diretrizes da International Conference on Harmonization. O método mostrou-se seletivo, pois não houve interferência dos adjuvantes na leitura das absorbâncias nas soluções analisadas. Apresentou coeficiente de correlação linear (r) de 0,9999, confirmando a linearidade do método. Os valores de desvio padrão relativo, obtidos tanto para precisão, nos níveis de repetibilidade e precisão intermediária, quanto para exatidão não excederam o máximo de 15% determinado nos critérios de aceitação para métodos bioanalíticos, considerando a complexidade da matéria-prima vegetal.

The aim of this study was to develop and validate an analytical method using UV spectrophotometry to determine total flavonoids, expressed in vitexin, in capsules containing a dry extract of Passiflora incarnata L. The analytical method was based on the spectrophotometric assay described in the British Pharmacopoeia (2010), for the dry extract of P. incarnata L. The validation of this method of quantitation was done in accordance with ANVISA resolution 899/2003 and the International Conference on Harmonization guidelines. The method was selective, because there was no interference from additives in the reading of the absorbance of solutions analyzed. It showed a linear regression correlation coefficient (r) of 0.9999, confirming the linearity of the method. The values of relative standard deviation calculated for precision (both repeatability and intermediate precision) and for accuracy did not exceed the maximum of 15% allowed in the acceptance criteria for bioanalytical methods, considering the complexity of the plant raw material.

Flavonoids , Passiflora , Spectrophotometry, Ultraviolet/methods
Article in Portuguese | LILACS | ID: lil-658493


This article reports a study of the influence of sodium starch glycolate (SSG) on the dissolution of nimesulide carried in hard gelatin capsules. Some physicochemical parameters of nimesulide were characterized and formulations containing three different contents of SSG were prepared, to compound the hard gelatin capsules of nimesulide. The capsules obtained, as well as the reference drug, were subjected to in vitro dissolution tests. During the maximum pharmacopoeial dissolution time, the amount of drug substance dissolved was determined and the dissolution profile was traced from the amount of drug dissolved in each time interval. The dissolution profiles were compared by the simple Model-Independent Method, by statistical assessment of the dissolution profile data for each time interval and by the dissolution efficiency (DE). The results show that SSG, used as a disintegrant, has a positive influence on the dissolution of nimesulide, facilitating the disintegration of the dosage form, increasing the contact surface of the drug with water and with it the dissolution rate. The N3 capsules, which had the highest content of SSG, 13% (w/w), complied with the pharmacopoeial specification for dissolution tests and the comparative tests of dissolution profiles showed that the N3 capsules exhibited rapid dissolution and an in vitro dissolution profile similar to that of the reference drug. Thus, the N3 capsules can be considered as a pharmaceutical alternative to the reference drug.

O presente trabalho avaliou a influência do Amido Glicolato de Sódio (AGS) na dissolução da nimesulida veiculada em cápsulas gelatinosas duras. Para tanto, foram caracterizados alguns parâmetros físico-químicos da nimesulida; e formulações, contendo diferentes concentrações de AGS, foram preparadas para compor as cápsulas gelatinosas duras de nimesulida. As cápsulas obtidas, bem como o medicamento referência, foram submetidos aos ensaios de dissolução in vitro. Determinou-se, para o tempo de dissolução máximo farmacopeico, a quantidade da substância ativa dissolvida, bem como traçou o perfil de dissolução a partir da quantidade de substância dissolvida em cada intervalo de tempo. A comparação dos perfis de dissolução foi realizada pelo Método Modelo Independente Simples, pela avaliação estatística dos dados dos perfis de dissolução para cada intervalo de tempo e pela Eficiência de Dissolução (ED). Os resultados mostram que o AGS, utilizado como desintegrante, tem características que interferem positivamente na dissolução da nimesulida, facilitando a desintegração da forma farmacêutica, aumentando a superfície de contato do ativo com a água e, com isso, a velocidade de dissolução. As cápsulas N3, que possuem 13% (p/p) de AGS, cumprem com as especificações farmacopeicas para os testes de dissolução, e ensaios comparativos de perfis de dissolução mostram que as cápsulas N3 apresentam dissolução rápida e perfil de dissolução in vitro semelhante ao medicamento referência. Logo, as cápsulas N3 podem ser consideradas como alternativas farmacêuticas aos comprimidos referência.

Anti-Inflammatory Agents, Non-Steroidal , Dissolution , Spectrophotometry, Ultraviolet/methods , Pharmaceutical Preparations , Solubility
Rev. bras. plantas med ; 14(3): 500-505, 2012. graf, tab
Article in Portuguese | LILACS | ID: lil-658131


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%).

Coumaric Acids/analysis , Validation Study , Methodology as a Subject , Quality Control , Spectrophotometry, Ultraviolet/methods , Alismataceae/metabolism
Braz. j. pharm. sci ; 46(2): 179-186, Apr.-June 2010. ilus, tab
Article in English | LILACS | ID: lil-564883


A dissolution test for tablets containing 100 mg of lamotrigine was developed and validated. The dissolution test was applied to compare the dissolution profile of Neural® with the reference product Lamictal®. The analysis procedure was carried out using a simple ultraviolet method at 267 nm. After the determination of solubility and sink conditions, the parameters selected were paddles at 50 rpm, 900 mL of 0.01 M hydrochloric acid, and 30 minutes duration (single point). This method was validated for specificity, linearity, accuracy, precision and robustness. Lamotrigine stability was also evaluated in dissolution medium.

A finalidade deste estudo foi desenvolver e validar um método de dissolução para o fármaco lamotrigina na forma farmacêutica comprimido. Este método também foi utilizado para comparar o perfil de dissolução entre o Neural® e o produto de referência Lamictal®. O procedimento analítico foi realizado utilizando-se espectrofotometria de absorção no ultravioleta (267 nm) como forma de quantificação do fármaco. Após a determinação da solubilidade e das condições sink, os parâmetros selecionados foram: pás (50 rpm), 900 mL de ácido clorídrico 0.01 M e o tempo de 30 minutos (único ponto). Este método foi validado através da especificidade, linearidade, exatidão, precisão e robustez. A estabilidade da lamotrigina também foi avaliada no meio de dissolução.

Anticonvulsants/analysis , Tablets/chemistry , Technological Development/analysis , Dissolution/methods , Spectrophotometry, Ultraviolet/methods , Pharmaceutical Preparations , Quality Control
Braz. j. pharm. sci ; 46(2): 265-272, Apr.-June 2010. ilus, tab
Article in English | LILACS | ID: lil-564893


Oxcarbazepine (OXC) is an important anticonvulsant and mood stabilizing drug. A pharmacopoeial monograph for OXC is not yet available and therefore the development and validation of a new analytical method for quantification of this drug is essential. In the present study, a UV spectrophotometric method for the determination of OXC was developed. The various parameters, such as linearity, precision, accuracy and specificity, were studied according to International Conference on Harmonization Guidelines. Batches of 150 mg OXC capsules were prepared and analyzed using the validated UV method. The formulations were also evaluated for parameters including drug-excipient compatibility, flowability, uniformity of weight, disintegration time, assay, uniformity of content and the amount of drug dissolved during the first hour.

Oxcarbazepina (OXC) é um fármaco anticonvulsivante e estabilizante do humor. O desenvolvimento e validação de método analítico para quantificação da OXC são de fundamental importância devido à ausência de monografias farmacopéicas oficiais para esse fármaco. Nesse trabalho, um método espectrofotométrico UV para determinação da OXC foi desenvolvido. O método proposto foi validado seguindo os parâmetros de linearidade, precisão, exatidão e especificidade de acordo com as normas da Conferência Internacional de Harmonização. Cápsulas de OXC 150 mg foram preparadas e analisadas utilizando-se o método analítico validado. As formulações foram avaliadas com relação à compatibilidade fármaco-excipientes, fluidez, determinação de peso, tempo de desintegração, doseamento, uniformidade de conteúdo e quantidade do fármaco dissolvido após 60 minutos.

Anticonvulsants/analysis , Methods , Validation Studies as Topic , Analysis of Variance , Capsules , Spectrophotometry, Ultraviolet/methods , Regression Analysis
Braz. j. pharm. sci ; 45(4): 723-727, Oct.-Dec. 2009. ilus, tab
Article in English | LILACS | ID: lil-543668


Acetylsalicylic acid (AAS) is a drug utilized as analgesic, anti-inflammatory, and antipyretic medication, available worldwide and commonly used in Brazil. Salicylic acid (AS) is a precursor in AAS synthesis and is also produced during its degradation. The official United States Pharmacopoeia (USP) suggests the determination of these drugs by high performance liquid chromatography (HPLC), with ultraviolet detection, but this method has neither a high sensitivity (S AAS=0.12 mAbs/(μg/mL) and S AS=0.48 mAbs/(μg/mL)) nor resolution (Rs=1.61). The purpose of this study was to develop a new more adequate, accurate method by liquid phase chromatography than the current official methodology, and to use this new method in the determination of the tenors of acetylsalicylic, as of salicylic acids in tablets. The parameters of the chromatographic system for both the AAS and AS were satisfactory. Selectivity was verified by absorption spectra comparison in the ultraviolet (UV) range, during and after substance retention time. The linear range for AAS was 0.21 to 0.39 mg/mL, and that for AS was 6.3 to 11.7 μg/mL. The correlation coefficients (r) of the analytical curves of AAS and AS were 0.9995 and 0.9988, respectively; and the detection and quantification limits for the AS were 0.23 and 0.69 μg/mL. The sensitivity (S AAS=1.88 mAbs/(μg/mL) and S AS=1.84 mAbs/(μg/mL)) and the resolution (Rs =5.06) show the improvement obtained using this method over that described by the USP.

O ácido acetilsalicílico (AAS) é um fármaco utilizado como analgésico, antiinflamatório, antipirético, sendo amplamente comercializado e consumido no Brasil e no mundo. Como precursor de sua síntese utiliza-se o ácido salicílico (AS) que também é produzido através de sua degradação. A metodologia oficial da Farmacopéia Americana (USP) preconiza a determinação destes fármacos por cromatografia líquida de alta eficiência (CLAE) com detecção por ultravioleta, mas este método não possui boa sensibilidade (S AAS=0,12 mAbs/(μg/mL) e S AS=0,48 mAbs/(μg/mL)) e resolução (Rs =1,61). O objetivo deste trabalho, visando a melhor adequação do sistema cromatográfico em relação à metodologia oficial, foi o desenvolvimento e otimização de um novo método por cromatografia em fase líquida para determinar os teores tanto do ácido acetilsalicílico quanto do salicílico em comprimidos. Os parâmetros da adequação do sistema cromatográfico para o AAS e para o AS foram satisfatórios. A seletividade foi verificada por comparações dos espectros de absorção no ultravioleta (UV) antes, durante e depois do tempo de retenção da substância. A faixa linear de trabalho para o AAS foi de 0,21 a 0,39 mg/mL e a do AS foi de 6,3 a 11,7 μg/mL. Os coeficientes de correlação (r) das curvas analíticas do AAS e do AS foram de 0,9995 e 0,9988, respectivamente e os limites de detecção e quantificação para o AS foram 0,23 e 0,69 μg/mL. A sensibilidade (S AAS=1,88 mAbs/(μg/mL) e S AS=1,84 mAbs/(μg/mL)) e a resolução (Rs=5,06) atestam a melhoria em relação ao método descrito na USP.

Analytic Sample Preparation Methods , Aspirin/analysis , Tablets/analysis , Chromatography, High Pressure Liquid/methods , Technological Development/analysis , Diagnosis/methods , Salicylates , Spectrophotometry, Ultraviolet/methods , Pharmacokinetics
Rev. cuba. farm ; 43(3)sept.-dic. 2009.
Article in Spanish | LILACS | ID: lil-531374


El clorhidrato de metformina es un derivado de la biguanida usado en la diabetes mellitus no insulina dependiente, reduce la concentración de glucosa sanguínea sin incrementar la secreción de insulina, se considera un agente antihiperglucemiante y no un fármaco hipoglucemiante. El desarrollo tecnológico requiere de métodos analíticos confiables que permitan la cuantificación del fármaco en diferentes etapas de la investigación. El objetivo de este trabajo fue la validación del método analítico, reportado en la Farmacopea de los Estados Unidos (USP 31, 2008), por espectrofotometría ultravioleta y la adaptación del método analítico, reportado en la misma farmacopea, para el análisis de los compuestos relacionados en la determinación del principio activo en el producto terminado, por cromatografía líquida de alta resolución, validados para el control de la calidad y estudio de estabilidad de las tabletas de metformina 500 mg. A las técnicas validadas, por métodos cromatográficos y espectrofotométricos se le determinaron los parámetros de desempeño, especificidad, linealidad, exactitud y precisión. Las curvas de calibración para cada método, se realizaron en el intervalo de 60 al 140 por ciento, donde fueron lineales con coeficientes de correlación igual a 0,9994 y 0,99903, respectivamente; la prueba estadística para el intercepto y la pendiente se consideró no significativa. Se obtuvieron recobrados de 100,01 y 99,1 por ciento, respectivamente, en el intervalo de concentraciones estudiados y las pruebas de Cochran´(G) y Student´s (t) resultaron no significativas. Los coeficientes de variación en los estudios de la repetibilidad fueron iguales a 1,4 y 0,8 por ciento, respectivamente, para las 6 réplicas ensayadas, mientras que en los análisis de la precisión intermedia las pruebas de Fischer y Student fueron no significativas. Los resultados permiten concluir que ambos métodos cumplen con los requisitos establecidos como aceptables para cada uno de los casos...

Metformin hydrochloride is a biguanide-derivative used in non-dependent insulin diabetes mellitus reducing the blood glucose concentration without increases insulin secretion, and it is considered a anti-hyperglycemia agent and not a hypoglycemia one. Technological development requires of a reliable analytical methods allowing drug quantification in different stages of research. The aim of present paper was the analytical method validation, reported in USA Pharmacopeia (USP 31,2008) by UV-spectrophotometry and the adaptation of abovementioned method reported in the same pharmacopeia, for analysis of compound related in determination of active principle in end product, by high-performance liquid chromatography validated for quality control and study of Metformin (500-mg) tablets stability. In validated techniques by chromatographic spectrophtometric methods we determined performance parameter, specificity, linearity, accuracy, and precision. Calibration curves for each method was performed in intervals of 60to 140 percent, where they were linear with correlation coefficients equal to 0.9994 and 0.99903, respectively. Statistical test for interceptor and slope was considered as non-significant. We achieved recoveries of 100.01 and 99.1, respectively during interval of study concentrations, and the Cochran (G) and Student's (t) tests were not significant. Variation coefficients in studies of repetition were equal to 1.4 and 0.8, respectively for the 6 assayed replica, whereas in average precision analysis, Fischer and Student tests were not significant. Results allow concluding that both methods fulfill the established requirements as acceptable for each of cases during the concentration interval established.

Chromatography, High Pressure Liquid/methods , Spectrophotometry, Ultraviolet/methods , Metformin/analysis , Validation Studies as Topic
Article in Portuguese | LILACS | ID: lil-535416


Cetoconazol é um antifúngico sintético, derivado imidazólico de amplo espectro de ação, efetivo no tratamento de infecções superficiais e sistêmicas. Foram estudadas diferentes metodologias para análise do cetoconazol em especialidades farmacêuticas diversas usando espectrofotometria no ultravioleta, no infravermelho e análise térmica. Os resultados mostram que a espectrofotometria ultravioleta é um método rápido, prático e econômico e apontam que outros métodos como a espectrofotometria no infravermelho e análise térmica são uma alternativa à análise do cetoconazol em diferentes especialidades farmacêuticas.

Ketoconazole is a synthetic broad-spectrum oral and topical antifungal drug derived from imidazole, effective in the treatment of superficial mycoses and systemic infections. In this study we have tested several methods to analyze ketoconazole in various pharmaceutical products containing this drug, employing techniques such as UV and IR spectrophotometry and thermal analysis. The results showed that UV spectrophotometryis a fast, practical and economical method and indicated that other methods, such as IR spectrophotometry and thermal analysis, could be good alternative methods for ketoconazole analysis in certain pharmaceutical forms.

Antifungal Agents , Pharmaceutical Preparations , Differential Thermal Analysis/methods , Spectrophotometry, Infrared/methods , Spectrophotometry, Ultraviolet/methods
Egyptian Journal of Chemistry. 2009; 52 (2): 153-165
in English | IMEMR | ID: emr-135665


The absorption spectra of some 4-arylhydrazo-2-phenyl-2-oxazoline-5-one derivatives, have been studied in organic solvents of different polarity. The diagnostic IR spectral bands are assigned and discussed in relation to molecular structure and hydrogen bond existing in the stable compounds in the hydrazo form. The presence of electron withdrawing group in the phenyl ring facilitates the charge migration and hence the proton transfer, thus the azohydrazo form may appear in these compounds, but the major compounds were in the hydrazo form. The fact that these compounds show evidence for intramolecular hydrogen bonding is in favor of the hydrazone structure, this fact excludes the possibility of azo structure. The electronic absorption bands are assigned to the corresponding electronic transitions and the effect of solvent parameters on the charge transfer energy [ECT] is investigated. Four absorbance bands appeared for hydrazones in the range 443-221 nm, the first band has Amax within the range 222-237 nm corresponding to the medium energy transition of the phenyl group e [1]La-[1]A]. The second band with [lambda]max at 243-257 nm is attributed to the low energy mm transition of the phenyl rings representing the [[1]Lb-[1]A] electronic state. The third band at 278-314 nm lies within the energy region for the mm excitation of the electrons of the hydrazo groups. The last band in the visible which has [lambda]max within the range 422-443 nm is considered as being due to an intramolecular charge transfer involving the whole molecule. Finally, the substitution effect was also studied

Spectrophotometry, Ultraviolet/methods , Spectrophotometry, Infrared/methods , Comparative Study
Egyptian Journal of Chemistry. 2009; 52 (2): 193-216
in English | IMEMR | ID: emr-135668


UV-visible and infrared absorption spectra of some selected commercial soda - lime - silicate glasses mixed with varied amounts of municipal glass cullet and doped with oxides of tin, manganese, and ceric before and after exposure to a high dose of gamma irradiation [5MR] were studied. XRF analysis showed that the municipal cullet contains high iron concentration and the results revealed that additions of [Mn + Ce + Sn] oxides produce colorless glasses even when containing high municipal cullet contents. It is generally observed that increasing the cullet content resulted in an optical spectrum consisting of three UV bands instead of two UV bands in case of low cullet content. The visible spectra reveal the resolution of two radiation induced bands at about 423 and 540 nm. Gamma irradiation also causes some of the absorption bands to be shifted in their positions. Experimental data are interpreted on the basis of current views on the spectroscopy of glasses

Sodium Hydroxide/chemistry , Glass/analysis , Spectrophotometry, Ultraviolet/methods , Spectrophotometry, Infrared/methods , Gamma Rays
RBCF, Rev. bras. ciênc. farm. (Impr.) ; 44(4): 621-628, out.-dez. 2008. ilus, graf, tab
Article in Portuguese | LILACS | ID: lil-507912


O ácido úsnico (AU) é um composto de origem liquênica e tem demonstrado importantes atividades biológicas, tais como: antitumoral, antimicrobiano, antiviral, antiproliferativo e antiinflamatório. Os lipossomas são vesículas lipídicas contendo espaço aquoso interno e têm sido utilizados como carreadores coloidais de fármacos, principalmente na terapêutica de câncer e infecções bacterianas e fúngicas. O objetivo desse trabalho foidesenvolver e validar um método espectrofotométrico UV para determinação de ácido úsnico em lipossomas. Os parâmetros de validação linearidade, precisão, exatidão, robustez, limites de detecção e quantificação foram determinados segundo diretrizes internacionais de padronização e Farmacopéia Americana. A faixa de linearidade foi de 3 a 15 μg.mL-1, a equação de regressão:absorbância = 0,070 x [AU] (μg.mL-1) + 0,013 e r = 0,9997. A repetibilidade (coeficiente de variação) do método foi 1,96% e a precisão intermediária indicou que a diferença entre as médiasfoi estatisticamente insignificante (P < 0,05). A exatidão revelou média percentual de recuperação de 100,4%. O método foi robusto apesar da variação de temperatura e solventes. Os limites de detecção e quantificação do ácido úsnico foram de 0,34 e 1,13 μg.mL-1, respectivamente. O doseamento do ácido úsnico nos lipossomas foi de 96,8% (± 0,2). O método proposto é exato, preciso e reprodutível sendo capaz de quantificar o ácido úsnicoem matéria-prima e em preparações farmacêuticas.

The secondary lichen metabolite usnic acid [2,6-diacetyl- 7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzofuran]has demonstrated pharmacological potential activities such as antitumor, antimicrobial, antiviral, antiproliferative, and anti-inflammatory. Liposomes arevesicles composed of phospholipid bilayers surrounding aqueous compartments and they have been used as colloidal drug carriers. The aim of this study was to develop and validate a quantitative UV spectrophotometric method for determination of usnicacid in liposomal formulations. The validation parameters were assessed according to The International Conference on Harmonization (ICH) and American Pharmacopoeia guidelines. The linearity range was of 3-15 μg.mL-1,regression equation: absorbance = 0.070 x UA concentration (μg.mL-1) + 0.013, and r = 0.9997. The repeatability (relative standard deviation) of the method was 1.96% and intermediate precision indicated that the difference among mean was statistically insignificant (P < 0.05). The accuracy revealed a mean percentage recovery of 100.4% of usnic acid. The method was robust for the variation of temperature and solvent. The detection and quantization limits were found to be 0.34 and 1.13 μg.mL-1, respectively. The content of usnic acid in liposomes was of 96.8% (± 0.2). The proposed method is accurate, precise and reproducible for estimation of usnic acid as raw material and in pharmaceutical dosage forms such as liposomes.

Liposomes , Pharmaceutical Preparations , Chromatography, High Pressure Liquid/methods , Spectrophotometry, Ultraviolet/methods