RESUMO
A simple HPLC method for determination of mefloquine hydrochloride in tablets was developed and validated. The separation was carried out on an Xterra RP18 (250 x 4.6 mm id, 5 pm particle size) analytical column. The mobile phase was 0.05 M monobasic potassium phosphate buffer (pH 3.5)-methanol (40 + 60, v/v). The flow rate and wavelength were set to 1 mL/min and 283 nm, respectively. The method was specific for mefloquine hydrochloride in the presence of hydrolytic, oxidative, and photolytic degradation products. It was also linear, precise, accurate, and robust, being suitable for routine QC analyses and stability studies. The developed HPLC method was compared to a previously described spectrophotometric method.
Assuntos
Antimaláricos/química , Cromatografia Líquida de Alta Pressão/métodos , Mefloquina/química , Estrutura Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Comprimidos/químicaRESUMO
Soy phytoestrogens, isoflavones, are a primary class of plant-based estrogen alternatives being sold over the counter nowadays. Genistein, daidzein and glycitein are the major isoflavones found in soybeans, as aglycones and glycosides. Each isoflavone shows distinctive estrogenic activity and pharmacokinetics. Soy dry extracts, employed as pharmaceutical raw material for manufacturing isoflavone supplements, are standardized to contain 40% of total isoflavones, but the amount of each isoflavone is highly diverse. The influence of these compositional differences on the estrogenic potency of soy extracts was evaluated by uterotrophic bioassay. Five commercial samples of standardized soy dry extract, homogeneously suspended in arachis oil, were administered per os in serial doses (125-4150 mg/kg bw/day) to immature female rats for 3 days. Soy extract samples with considerable diversity in isoflavone composition revealed different estrogenic potencies. Our results indicate a need of standardization of the individual isoflavone content in soy extracts.
Assuntos
Bioensaio/métodos , Glycine max/química , Isoflavonas/farmacologia , Fitoestrógenos/farmacologia , Extratos Vegetais/farmacologia , Útero/efeitos dos fármacos , Administração Oral , Animais , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Estrogênios/farmacologia , Feminino , Fulvestranto , Isoflavonas/análise , Tamanho do Órgão/efeitos dos fármacos , Fitoestrógenos/análise , Extratos Vegetais/química , Extratos Vegetais/normas , Ratos , Ratos Wistar , Útero/crescimento & desenvolvimentoRESUMO
A simple procedure for obtaining and purifying two degradation products of efavirenz (amino alcohol and quinoline derivatives) from drug substance hydrolysis is described. These impurities are known to exhibit very different UV absorbance properties from those of the parent compound, making determination using a quantitation factor (QF) inaccurate. The obtained hydrolysis products were characterized by physicochemical methods to assure identity, purity and strength. Quinoline derivative was of high purity degree (100%) and amino alcohol was 98.74% pure. Both were set as reference standards in chromatographic related compounds test for efavirenz drug substance and tablets analyses.
Assuntos
Fármacos Anti-HIV/análise , Oxazinas/análise , Alcinos , Amino Álcoois/análise , Benzoxazinas , Fenômenos Químicos , Físico-Química , Cromatografia em Camada Fina , Ciclopropanos , Hidrólise , Espectroscopia de Ressonância Magnética , Quinolinas/análise , Padrões de Referência , Análise de Regressão , Espectrofotometria Infravermelho , ComprimidosRESUMO
A comparison of different methods for dissolution test used by five different manufacturer laboratories of lamivudine tablets is made, evaluated, and discussed. Dissolution medium (water and hydrochloric acid pH 1.2), apparatus (paddles and baskets) and time (30 and 60 min) were analyzed. The determination was accomplished by spectrophotometry at 270 nm. Analysis of variance (ANOVA) factorial design 5 x 2 x 2 x 2 with six repetitions, with post hoc multiple comparisons between means conducted by Duncan test at 0.05 significance level was used. After the comparative analysis of the results, optimal dissolution conditions were determined as follows: water as dissolution medium, paddles at the stirring speed of 50 rpm as apparatus and time of 30 min. The method was applied to the dissolution test of samples from eleven batches of tablets, produced by five different laboratories.
Assuntos
Fármacos Anti-HIV/química , Lamivudina/química , Análise de Variância , Fármacos Anti-HIV/normas , Ácido Clorídrico/química , Concentração de Íons de Hidrogênio , Lamivudina/normas , Controle de Qualidade , Solubilidade , Comprimidos , Água/químicaRESUMO
Isoflavones are widely used as an alternative treatment to hormone replacement therapy and also for prevention of several chronic diseases, including cancers. Genistein, daidzein and glycitein are the most abundant isoflavone aglycones found in soy extracts, where they also occur as glycosides. This paper describes the development and validation of an isocratic reversed-phase HPLC (RP-HPLC) method for the analysis of isoflavone aglycones, released after acid hydrolysis of soy dry extracts, used as pharmaceutical raw material. The quantification was carried out in a C(18) endcapped column, using a mobile phase composed of 0.1% acetic acid and methanol (52:48), at a flow rate of 1.0 ml/min and diode array detection (DAD) at 254 nm. The method showed to be linear (r(2)>0.99), precise (R.S.D.<2%), accurate (recovery of 98.88% for daidzein and 98.12% for genistein), robust and specific.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Glycine max/química , Isoflavonas/análise , Extratos Vegetais/química , Hidrólise , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
A lamivudina é um fármaco indicado para o tratamento de infecção por HIV, tipos 1 e 2. Tem sido extensivamente utilizada no Brasil, em programa público do Ministério da Saúde. Visando à verificação da qualidade dos medicamentos contendo este fármaco foi estabelecida e validada metodologia para determinação do teor da lamivudina. Foi também realizado estudo de equivalência farmacêutica frente ao medicamento referência. Parâmetros físicos e físico-químicos de comprimidos de liberação imediata de diferentes lotes de quatro laboratórios (G, A, B e C) foram avaliados. O método proposto para o doseamento, por cromatografia líquida de alta eficiência, mostrou precisão, exatidão, linearidade e especificidade...
Assuntos
HIV , Lamivudina , Comprimidos , Cromatografia Líquida/métodos , Equivalência TerapêuticaRESUMO
Foram investigadas as atividades antibacteriana e antifúngica dos extratos éter de petróleo e alcaloídico de folhas de Aristolochia gigantea Mart e Zucc, pelo método de difusäo em agar. O extrato éter de petróleo mostrou atividade contra uma bactéria Gram-positiva. O extrato alcaloídico apresentou atividade contra duas bactérias Gram-positivas. Uma Gram-negativa, näo apresentando qualquer atividade antifúngica.
Assuntos
Antígenos de Bactérias/imunologia , Antígenos de Fungos/imunologia , Antifúngicos/imunologia , Aspergillus niger/imunologia , Bacillus subtilis/imunologia , Candida/imunologia , Escherichia coli/imunologia , Extratos Vegetais/imunologia , Pseudomonas aeruginosa/imunologia , Saccharomyces cerevisiae/imunologia , Staphylococcus aureus/imunologia , Bactérias Gram-Negativas/imunologia , Bactérias Gram-Positivas/imunologiaRESUMO
Foram testadas as atividades antibacterianas de extratos de folhas, flores, caule e raizes de Aristolochia gigantea Mart e Zucc e de Aristolochia glandulosa Ferrari, frente a bactérias Gram-positivas e Gram-negativas, pelo método de difusäo em placa. Cinco extratos mostraram-se ativos.
