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ABSTRACT: An alternative methodology for simultaneous analysis of ethambutol, isoniazid, rifampicin and pyrazinamide in pharmaceutical formulations by capillary zone electrophoresis under UV direct detection with an analysis time of 8.0 min is proposed. Background running was based on the effective mobility curve of the analytes and an optimum separation condition was achieved using a 3(3) Box-Behnken design, with Brij 35, Cu(2+) and acetic acid/sodium acetate buffer as factors. An electrolyte consisting of 50.0 mmol L(-1) of acetic acid/sodium acetate buffer, 12.5 mmol L(-1) of CuSO(4), and standard and sample solutions prepared in 2.00 mmol L(-1) of Brij 35 and 12.5 mmol L(-1) of CuSO(4) were optimized. After evaluating validation parameters, the method was successfully applied to the analysis of samples in the form of tablets and sachets.
Talanta 06/2010; 82(1):333-9. · 3.79 Impact Factor
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ABSTRACT: A method for the determination of ethambutol (EMB), a first-line drug against tuberculosis, based on CE with capacitively coupled contactless conductivity detection is proposed. The separation of EMB and its main product of degradation were achieved in less than 3 min with a resolution of 2.0 using a BGE composed of 50 mmol/L histidine and 30 mmol/L MES, pH 6.30. By raising the pH to 8.03, the analysis time was reduced to 1.0 min, but with a significant loss of resolution (0.7). Using the best separation conditions, linearity of 0.9976 (R(2), five data points), sensitivity of 1.26x10(-4) V min mumol(-1) L, and LOD and quantification of 23.5 and 78.3 mumol/L, respectively, were obtained. Recoveries at four levels of concentration ranged from 95 to 102% and the concentration range studied ranged from 100 to 500 mumol/L. The results obtained for the determination of EMB in pharmaceutical formulations were compared with those obtained by using CE with photometric detection.
Electrophoresis 01/2010; 31(3):570-4. · 3.30 Impact Factor
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ABSTRACT: An alternative methodology for the determination of ethambutol by capillary zone electrophoresis (CZE) under direct UV detection at 262 nm, using acetic acid/sodium acetate buffer solution (pH 4.6) containing copper(II) sulphate to form the ethambutol-copper(II) complex, within analysis time of 2.5 min is proposed. The optimum CE conditions for the background electrolyte were established performing experiments of a 3(2) factorial design. Complex formation was evidenced by the UV batochromic shift and the [CuETB](0) and [CuETB](2+) chemical structures were indicated by LC-MS analysis. After some validation parameters have been performed, such as linearity (r=0.999), selectivity (comparison between slope of the calibration curve of the external standard and calibration curve of the standard addition), area precision (RSD%: <2.13 for ETB and <1.94 for 2A1B), recovery mean (101.7% for ETB and 99.95% for 2A1B) and quantification limit (mg L(-1): 10.17 for ETB and 19.70 for 2A1B), the method was successfully applied to ETB analysis in pharmaceutical formulation samples. It is possible to determine the presence of the 2A1B impurity at concentrations of less than 1% ETB content.
Journal of Chromatography 08/2008; 1202(2):224-8. · 4.53 Impact Factor
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ABSTRACT: b Instituto de Tecnologia em Fármacos-Far Manguinhos, Fundação Oswaldo Cruz, 21041-250 Rio de Janeiro-RJ, Brazil Um método alternativo por eletroforese capilar de zona (CZE) para determinação de ciprofloxacina (CPFLX), gatifloxacina (GTFLX), moxifloxacina (MFLX) e ofloxacina (OFLX) foi validado. O sistema de eletrólito utilizado consistiu da mistura de 25 mmol L -1 de TRIS/ HCl e 15 mmol L -1 de tetraborato de sódio em meio aquoso resultando em pH 8,87. A análise foi realizada sob detecção direta por UV em 282 nm com tempo de análise de 3 min. Os parâmetros analíticos de validação avaliados foram: linearidade (r > 0,998), seletividade (comparação entre a inclinação da curva de calibração de padronização externa e curva de calibração de adição de padrão), repetitividade em área para amostras (RSD %: < 3,94% para CPFLX, < 3,87% para GTFLX, 1,30% para MFLX e < 1,88% para OFLX), precisão intermediária em área para amostras (RSD%: < 3,59% para CPFLX, < 3,09% para GTFLX, 2,67% para MFLX e < 2,25% para OFLX), exatidão (média da faixa de recuperação: 101,2% para CPFLX, 101,0% para GTFLX, 101,3% para MFLX e 99,9% para OFLX), limite de detecção (mg L -1 : 2,72 para CPFLX, 1,92 para GTFLX, 0,795 para MFLX e 1,05 para OFLX), limite de quantificação (mg L -1 : 9,06 para CPFLX, 6,40 para GTFLX, 2,65 para MFLX e 3,50 para OFLX) e robustez. Devido à simplicidade, seletividade, precisão, exatidão e rapidez, o método pode ser uma alternativa interessante para auxiliar o controle da qualidade dessas drogas na indústria farmacêutica. An alternative capillary zone electrophoresis (CZE) method for the determination of ciprofloxacin (CPFLX), gatifloxacin (GTFLX), moxifloxacin (MFLX) and ofloxacin (OFLX) through a simple aqueous electrolyte system consisting of 25 mmol L -1 of TRIS/ hydrochloride and 15 mmol L -1 of sodium tetraborate buffer mixture (pH 8.87) using direct UV detection at 282 nm within 3 min was validated. The analytical parameters of validation evaluated were: linearity (r > 0.998), selectivity (comparison between slope of the calibration curve of external standard and calibration curve of standard addition), repeatability in area for sample (RSD%: < 3.94% for CPFLX, < 3.87% for GTFLX, 1.30% for MFLX and < 1.88% for OFLX), intermediate precision in area for sample (RSD%: < 3.59% for CPFLX, < 3.09% for GTFLX, 2.67% for MFLX and < 2.25% for OFLX), accuracy (mean of recovery range: 101.2% for CPFLX, 101.0% for GTFLX, 101.3% for MFLX and 99.9% for OFLX), limit of detection (mg L -1 : 2.72 for CPFLX, 1.92 for GTFLX, 0.795 for MFLX and 1.05 for OFLX), limit of quantification (mg L -1 : 9.06 for CPFLX, 6.40 for GTFLX, 2.65 for MFLX and 3.50 for OFLX) and robustness. Due to its simplicity, selectivity, precision, accuracy and rapidity, the methodology can be an interesting alternative for quality assurance in the pharmaceutical industry of these drugs.
Article J. Braz. Chem. Soc. J. Braz. Chem. Soc. 01/2008; 19(390):389-396.
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ABSTRACT: Uma metodologia alternativa por eletroforese capilar de zona (ECZ) é proposta para a análise de losartan potássio (LOS) associado com clortalidona (CTD) ou hidroclorotiazida (HCT) em cápsulas, usando 50 mmol L -1 de tampão carbonato de sódio com detecção em 226 nm. O sistema de eletrólito foi otimizado, levando em consideração o perfil do pico, resolução, tempo de análise, estabilidade da linha base e repetibilidade (ausência de adsorção). O método foi aplicado com sucesso na análise de formulações farmacêuticas adquiridas em farmácias de manipulação. Os analitos apresentaram boa separação na linha base em menos de 5 min. Os resultados obtidos não apresentaram diferença signicativa no intervalo de 95% de confiança em relação ao valor de referência. O método pode ser aplicado para a análise destes compostos ou empregado em outros formulações framacêuticas similares contendo estas drogas. An alternative methodology by capillary zone electrophoresis (CZE) is proposed for the determination of losartan potassium (LOS) associated with chlorthalidone (CTD) or hydrochlorothiazide (HCT) in capsules, using 50 mmol L -1 of sodium carbonate buffer with detection at 226 nm. The electrolyte system was optimized, taking into account peak profiles, resolution, run times, baseline stability and repeatability (adsorption absence). The method was successfully applied to the analysis of pharmaceutical formulations purchased in manipulation drugstores. The analytes were baseline separated in less than 5 min. The results did not present significant difference in the 95% confidence interval in relation to the label claim values. The method can be applied to analyze these compounds and could also be employed in other similar formulated products containing these drugs.
J. Braz. Chem. Soc. 01/2007; 18:554-558.
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ABSTRACT: A novel methodology has been developed for simultaneous separation of ciprofloxacin (CPFLX), gatifloxacin (GTFLX), levofloxacin (LVFLX), moxifloxacin (MFLX) and sparfloxacin (SPFLX) fluoroquinolone antibiotics (FQs), using capillary zone electrophoresis (CZE) with UV detection at 282 nm. Electrolyte composition was optimized through the variation of the Tris/hydrochloride and sodium tetraborate buffer mixture. The electrolyte consisted of a 25 mmol L(-1) Tris/hydrochloride and 15 mmol L(-1) sodium tetraborate buffer mixture resulting in pH 8.87. All analytes were separated in less than 3 min. The proposed method was applied to the separation of FQs in pharmaceutical formulations, and the assay results were within 95-105% of the label claim.
Analytica chimica acta 11/2006; 579(2):185-92. · 4.31 Impact Factor
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ABSTRACT: An alternative methodology for simultaneous analysis of ethambutol, isoniazid, rifampicin and pyrazinamide in pharmaceutical formulations by capillary zone electrophoresis under UV direct detection with an analysis time of 8.0 min is proposed. Background running was based on the effective mobility curve of the analytes and an optimum separation condition was achieved using a 33 Box-Behnken design, with Brij 35, Cu2+ and acetic acid/sodium acetate buffer as factors. An electrolyte consisting of 50.0 mmol L−1 of acetic acid/sodium acetate buffer, 12.5 mmol L−1 of CuSO4, and standard and sample solutions prepared in 2.00 mmol L−1 of Brij 35 and 12.5 mmol L−1 of CuSO4 were optimized. After evaluating validation parameters, the method was successfully applied to the analysis of samples in the form of tablets and sachets.
Talanta.
