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Made available in DSpace on 2014-12-17T15:42:17Z (GMT). No. of bitstreams: 1 SeverinaDSO_DISSERT.pdf: 2512071 bytes, checksum: 12a15e7529d5b018959d5e9c644f10cf (MD5) Previous issue date: 2013-07-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work a study was done using electrochemical cyclic voltammetry and differential pulse voltammetry for isoniazida (INH), ethambutol (EMB), rifampicina (RIF) and pyrazinamide (PZA) using the electrode boron-doped diamond (BDD) as working electrode. It also verified the applicability of the technique of differential pulse voltammetry in the quantification of the active compounds used in the treatment of tuberculosis, subsequently applying in samples of pharmaceutical formulation. Among the four active compounds studied, isoniazid showed the best results for the detection and quantification using differential pulse voltammetry. At pH 4 and pH 8, for the calibration curves to INH showed good linearity, with quantification limits of 6.15 mmol L-1 (0,844 ppm) and 4.08 mmol L-1 (0.560 ppm) for the respective pH. The proposed method can be used to determine drug isoniazid, for recovery values were obtained in approximately 100% / Neste trabalho foi feito um estudo eletroqu?mico utilizando a voltametria c?clica e voltametria de pulso diferencial para os f?rmacos isoniazida (INH), etambutol (EMB), rifampicina (RIF) e pirazinamida (PZA) usando o eletrodo de diamante dopado com boro (BDD) como eletrodo de trabalho. Foi tamb?m verificado a aplicabilidade da t?cnica de voltametria de pulso diferencial na quantifica??o dos princ?pios ativos usados no tratamento da tuberculose, posteriormente aplicando em amostras de formula??o farmac?utica. Dentre os quatro princ?pios ativos estudados, a isoniazida apresentou os melhores resultados de detec??o e quantifica??o com o uso da voltametria de pulso diferencial. Em pH 4 e pH 8, as curvas de calibra??o para a INH apresentaram boa linearidade, apresentando os limites de quantifica??o de 6,15 μmol L-1 (0,844 ppm) e 4,08 μmol L-1 (0,560 ppm), para os respectivos pH. O m?todo proposto pode ser usado para a determina??o de isoniazida em f?rmacos, pois foram obtidos valores de recupera??o em torno de 100%

Submitted by Alexandre Sousa (alexandre.sousa@incqs.fiocruz.br) on 2014-10-21T17:51:39Z No. of bitstreams: 1 Dissertação PatríciaCondéde Lima.pdf: 2501003 bytes, checksum: ae9bd16a44582c654071a25e36e5497e (MD5) / Made available in DSpace on 2014-10-21T17:51:39Z (GMT). No. of bitstreams: 1 Dissertação PatríciaCondéde Lima.pdf: 2501003 bytes, checksum: ae9bd16a44582c654071a25e36e5497e (MD5) Previous issue date: 2014 / Fundação Oswaldo Cruz. Instituto Nacional de Controle de Qualidade em Saúde. Departamento de Química. Rio de Janeiro, RJ, Brasil. / Oscomprimidosutilizadosno tratamento da tuberculose possuem quatro fármacos associados, Isoniazida(INH), Pirazinamida(PYA), Etambutol(EMB) e Rifampicina(RMP) e são distribuídos gratuitamente pelo Sistema Único de Saúde. Até o momento, os métodos analíticos oficiais para a análise dos teores dos fármacos presentes neste medicamento de dose fixa combinada são aqueles especificados na Farmacopeia Americana 36ª edição e na Farmacopeia Internacional 4ª edição. Porém, nenhum destes compêndios oficiais possui monografias para análise simultânea dos quatro fármacos. O desenvolvimento de métodos analíticos adequados para determinar simultaneamente as concentrações dos quatro fármacos em comprimidos dose fixa combinada é de grande importância para o controle da qualidade do medicamento em questão. O objetivo deste estudo foi desenvolver um método analítico para determinar simultaneamente todos os princípios ativos do comprimido para o tratamento da tuberculose por cromatografia a líquido de alta eficiência com detector de ultravioleta-visível. O método desenvolvido utilizou uma coluna cromatográfica com fase estacionária octadecilsila no, 250mm de comprimento, 4,6mm de diâmetro e5 μm de tamanho de partícula e fase móvel constituída de uma fase aquosa(85% tampão formiato de amônio 0,3 mol/L pH 5, 15%metanol e 0,005 mol/L de Cu2+ou 250 mg/L de CuSO4.5H2O) e fase orgânica(metanol, 0,1% de trietilamina e 0,2% de ácido fórmico). O fluxo empregado foi de 1,0 mL/min e comprimento de onda265 nm, quando o software do equipamento permitiu, para a INH, PYA e o EMB um comprimento de onda de 265 e de 335 nm para a RMP. Este estudo demonstrou que o método desenvolvido apresentou linearidade entre 0,05 a 0,10 mg/mL para INH, 0,27 a 0,52 mg/mL para PYA, 0,19 a 0,36 mg/mL para EMB e 0,05 a 0,1 mg/mL para RMPe mostrou-se satisfatório quanto ao parâmetro de precisão, com desvio padrão relativo inferior a 2,0% para os quatro fármacos estudados. / Tablets used to treat tuberculosis contain four drugs, isoniazid (INH), pyrazinamide (PYA), ethambutol (EMB) and rifampicin (RMP) and are freely distributed by the National Health System. So far, the official analytical methods for testing the amount of the ingredients present in the fixed-dose combination tablet are those described in the 36th editionof U.S. Pharmacopeia and in the 4th editionof International Pharmacopoeia. However, none of these official compendium present monographs for the simultaneous analysis of the four drugs. The development of suitable analytical methods for simultaneously determining the concentrations of the four drugs in fixed-dose combination tablets is of great importance to the quality control of the medicinal product concerned. The aim of this study was to develop an analytical method to simultaneously determine all the active ingredients of the tablet for tuberculosis treatment by high-performance liquid chromatography with ultraviolet-visible detector. The developed method used a chromatographic column with octadecylsilane stationary phase, with 250mm length, 4,6mm diameter and 5 μm particle size. The mobile phase was aqueous (85% ammonium formate buffer 0,3 mol/LpH 5, 15% methanol and 0,005 mol/Lof Cu2+or250 mg/LCuSO4.5H2O), and the organic phase(methanol, 0,1% triethylamine and 0,2 % formic acid). The used flow was 1,0mL/min, at a wavelength of 265 nm or when the equipment alloweda wavelength of 265 nm for INH, EMB, and PYA and 335nmfor RMP. This study showned that the developed method was linear from 0,05 to 0,10 mg/mL for INH, 0,27 to 0,52 mg/mL for PYA, 0,19 to 0,36 mg/mL for EMB and 0,05 to0,1 mg/mL for RMP and was satisfactory regarding the precision parameter, with relative standard deviation lower than 2,0 % for the four studied drugs.

Made available in DSpace on 2014-12-17T14:16:26Z (GMT). No. of bitstreams: 1 EdilenePL_DISSERT.pdf: 1151865 bytes, checksum: 7a412187753da50d4030404745c567f7 (MD5) Previous issue date: 2010-02-26 / According to the global framework regarding new cases of tuberculosis, Brazil appears at the 18th place. Thus, the Ministry of Health has defined this disease as a priority in the governmental policies. As a consequence, studies concerning treatment and prevention have increased. Fixed-dose combination formulations (FDC) are recognized as beneficial and are recommended by WHO, but they present instability and loss on rifampicin bioavailability. The main purpose of this work was to carry out a pre-formulation study with the schedule 1 tuberculosis treatment drugs: rifampicin, isoniazid, pyrazinamide and ethambutol and pharmaceutical excipients (lactose, cellulose, magnesium stearate and talc), in order to develop an FDC product (150 mg of rifampicin + 75 mg of isoniazid + 400 mg of pyrazinamide + 250 mg of ethambutol). The studies consisted of the determination of particle size and distribution (Ferret s diameter) and shape through optical microscopy, as well as rheological and technological properties (bulk and tapped densities, Hausner Factor, Carr s Index, repose angle and flux rate) and interactions among drugs and drug excipient through thermal analysis (DSC, DTA, TG and your derivate). The results showed that, except isoniazid, the other drugs presented poor rheological properties, determined by the physical characteristics of the particles: small size and rod like particles shape for rifampicin; rectangular shape for pyrazinamide and ethambutol, beyond its low density. The 4 drug mixture also not presented flowability, particularly that one containing drug quantity indicated for the formulation of FDC products. In this mixture, isoniazid, that has the best flowability, was added in a lower concentration. The addition of microcrystalline cellulose, magnesium stearate and talc to the drug mixtures improved flowability properties. In DSC analysis probable interactions among drugs were found, supporting the hypothesis of ethambutol and pyrazinamide catalysis of the rifampicin-isoniazid reaction resulting in 3- formylrifamycin isonicotinyl hydrazone (HYD) as a degradation product. In the mixtures containing lactose Supertab? DSC curves evidenced incompatibility among drugs and excipient. In the DSC curves of mixtures containing cellulose MC101?, magnesium stearate and talc, no alterations were observed comparing to the drug profiles. The TG/DTG of the binary and ternary mixtures curves showed different thermogravimetrics profiles relating that observed to the drug isolated, with the thermal decomposition early supporting the evidences of incompatibilities showed in the DSC and DTA curves / De acordo com o quadro mundial da tuberculose, o Brasil ocupa o 18? lugar em n?mero de casos novos, assim o Minist?rio da Sa?de definiu a doen?a como prioridade entre as Pol?ticas Governamentais de Sa?de. Desde ent?o se intensificaram os estudos relacionados ao tratamento e preven??o desta doen?a. As formula??es em dose fixa combinada (DFC) s?o reconhecidas como ben?ficas e apoiadas pela OMS, mas apresentam problemas de instabilidade e queda na biodisponibilidade da rifampicina. O objetivo principal desse trabalho foi realizar estudo de pr?-formula??o com os f?rmacos que integram o esquema 1 para o tratamento da tuberculose: rifampicina, isoniazida, pirazinamida e etambutol e excipientes farmac?uticos (lactose, celulose, estearato de magn?sio e talco), visando o desenvolvimento de um produto em dose fixa combinada (150 mg de rifampicina + 75 mg de isoniazida + 400 mg de pirazinamida + 250 mg de etambutol). Os estudos consistiram na determina??o do tamanho e distribui??o das part?culas (di?metro de Ferret) e forma por microscopia ?ptica, al?m das propriedades reol?gicas e tecnol?gicas (densidades aparente e de compacta??o, Fator de Hausner, ?ndice de Carr, ?ngulo de repouso e velocidade de escoamento) e das intera??es entre os f?rmacos e f?rmacos-excipientes por an?lise t?rmica (DSC, DTA, TG e sua derivada). Os resultados mostraram que ? exce??o da isoniazida, os demais f?rmacos apresentaram propriedades reol?gicas pobres, determinadas pelas caracter?sticas f?sicas das part?culas: tamanho reduzido e forma de agulhas da rifampicina; forma retangular da pirazinamida e etambutol, al?m da baixa densidade deste ?ltimo. A mistura dos quatro ativos tamb?m n?o apresentou fluxo, especialmente a prepara??o contendo a quantidade de f?rmacos preconizada para a formula??o de produtos em dose fixa combinada, uma vez que nessa mistura, a isoniazida, que possui o melhor fluxo, foi adicionada a uma concentra??o menor. A adi??o de celulose microcristalina, estearato de magn?sio e talco ?s misturas dos f?rmacos, melhorou as propriedades de fluxo. Nas an?lises por DSC foram encontradas prov?veis intera??es entre as subst?ncias ativas, refor?ando a hip?tese de cat?lise por etambutol e pirazinamida para a rea??o entre rifampicina e isoniazida que resulta no produto de degrada??o 3-(isonicotinoilhidrazinometil)rifamicina. Nas curvas de DSC das misturas contendo lactose Supertab? foi evidenciada a ocorr?ncia de incompatibilidade entre os f?rmacos e o excipiente. As curvas de DSC das misturas contendo celulose MC101?, estearato de magn?sio e talco n?o apresentaram altera??es em rela??o ao perfil dos f?rmacos. As curvas de TG/DTG das misturas bin?rias e tern?rias apresentaram perfis termogravim?tricos diferentes em rela??o ao observado para os f?rmacos isoladamente, com in?cio da decomposi??o t?rmica antecipada, dando suporte as evid?ncias de incompatibilidades encontradas nas curvas de DSC e DTA

Tuberculosis is an ancient infectious disease and a leading cause of death globally. Preclinical research is important for defining drugs and regimens which should be carried forward to human studies. This thesis aims to characterize the population pharmacokinetics and exposure-response relationships of anti-tubercular drugs alone and in combinations, and to suggest experimental designs for preclinical settings. The population pharmacokinetics of rifampicin, isoniazid, ethambutol and pyrazinamide were described for the first time in two mouse models. This allowed for linking the population pharmacokinetic model to the Multistate Tuberculosis Pharmacometric (MTP) model for biomarker response, which was used to characterize exposure-response relationships in monotherapy. Pharmacodynamic interactions in combination therapies were quantitatively described by linking the MTP model to the General Pharmacodynamic Interaction (GPDI) model, which provided estimates of single drug effects together with a quantitative model-based evaluation framework for evaluation of pharmacodynamic interactions among drugs in combinations. Synergism (more than expected additivity) was characterized between rifampicin and ethambutol, while antagonism (less than expected additivity) was characterized between rifampicin and isoniazid in combination therapies. The new single-dose pharmacokinetic design with enrichened individual sampling was more informative than the original design, in which only one sample was taken from each mouse in the pharmacokinetic studies. The new oral zipper design allows for informative pharmacokinetic sampling in a multiple-dose administration scenario for characterizing pharmacokinetic-pharmacodynamic relationships, with similar or lower bias and imprecision in parameter estimates and with a decreased total number of animals required by up to 7-fold compared to the original design. The optimized design for assessing pharmacodynamic interactions in the combination therapies, which was based on EC20, EC50 and EC80 of the single drug, provided lower bias and imprecision than a conventional reduced four-by-four microdilution checkerboard design at the same total number of samples required, which followed the 3Rs of animal welfare. In summary, in this thesis the population pharmacokinetic-pharmacodynamic models of first-line drugs in mice were characterized through linking each population pharmacokinetic model to the MTP model. Pharmacodynamic interactions were quantitatively illustrated by the MTP-GPDI model. Lastly, experimental designs were optimized and recommended to both pharmacokinetic and pharmacodynamic studies for preclinical settings.

With approximately nine million new cases and the attributable cause of death of an estimated two millions people every year there is an urgent need for new and effective drugs and treatment regimens targeting tuberculosis. The tuberculosis drug development pathway is however not ideal, containing non-predictive model systems and unanswered questions that may increase the risk of failure during late-phase drug development. The aim of this thesis was hence to develop pharmacometric tools in order to optimize the development of new anti-tuberculosis drugs and treatment regimens. The General Pulmonary Distribution model was developed allowing for prediction of both rate and extent of distribution from plasma to pulmonary tissue. A distribution characterization that is of high importance as most current used anti-tuberculosis drugs were introduced into clinical use without considering the pharmacokinetic properties influencing drug distribution to the site of action. The developed optimized bronchoalveolar lavage sampling design provides a simplistic but informative approach to gathering of the data needed to allow for a model based characterization of both rate and extent of pulmonary distribution using as little as one sample per subject. The developed Multistate Tuberculosis Pharmacometric model provides predictions over time for a fast-, slow- and non-multiplying bacterial state with and without drug effect. The Multistate Tuberculosis Pharmacometric model was further used to quantify the in vitro growth of different strains of Mycobacterium tuberculosis and the exposure-response relationships of three first line anti-tuberculosis drugs. The General Pharmacodynamic Interaction model was successfully used to characterize the pharmacodynamic interactions of three first line anti-tuberculosis drugs, showing the possibility of distinguishing drug A’s interaction with drug B from drug B’s interaction with drug A. The successful separation of all three drugs effect on each other is a necessity for future work focusing on optimizing the selection of anti-tuberculosis combination regimens. With a focus on pharmacokinetics and pharmacodynamics, the work included in this thesis provides multiple new methods and approaches that individually, but maybe more important the combination of, has the potential to inform development of new but also to provide additional information of the existing anti-tuberculosis drugs and drug regimen.

This study firstly reports the development and characterization of PVP-AgNPs, PANSA and PVPAgNPs/ PANSA nanocomposite on gold. AFM and TEM analyses revealed highly electroactive nanocomposites whose morphogy and properties were essential for the immobilization of CYP2E1. Secondly, the development and characterization of Au/PVPAgNPs/ PANSA/CYP2E1, Au/PVP-AgNPs/PANSA/SA-CYP2E1 and Au/PVPAgNPs/ PANSA/EG-CYP2E1 nanobiosensors are reported. AFM studies displayed globular morphologies with large roughness for the enzyme modified electrodes as opposed to those electrodes without enzymes. Finally, the biotransformation of standard solutions of TB drugs (isoniazid, ethambutol, pyrazinamide and rifampicin) in pH 7.4, 0.1 M phosphate buffer solution is reported. The biotransformations of the TB drugs were successfully studied using cyclic voltammetry (CV), square wave voltammetry (SWV), differential voltammetry (DPV) and steady state amperometry under aerobic conditions. Very good detection limits were obtained for the standard solutions of TB drugs and were found to be in the micromolar range. The detection limit values for the individual TB drugs were 0.55 μM (isoniazid), 0.7 μM (ethambutol), 0.054 μM (pyrazinamide) and 0.05 μM (rifampicin). The detection limit results showed that the nanobiosensors were more sensitive and suitable for the determination of the respective drugs in plasma and serum.

This study firstly reports the development and characterization of PVP-AgNPs, PANSA and PVPAgNPs/ PANSA nanocomposite on gold. AFM and TEM analyses revealed highly electroactive nanocomposites whose morphogy and properties were essential for the immobilization of CYP2E1. Secondly, the development and characterization of Au/PVPAgNPs/ PANSA/CYP2E1, Au/PVP-AgNPs/PANSA/SA-CYP2E1 and Au/PVPAgNPs/ PANSA/EG-CYP2E1 nanobiosensors are reported. AFM studies displayed globular morphologies with large roughness for the enzyme modified electrodes as opposed to those electrodes without enzymes. Finally, the biotransformation of standard solutions of TB drugs (isoniazid, ethambutol, pyrazinamide and rifampicin) in pH 7.4, 0.1 M phosphate buffer solution is reported. The biotransformations of the TB drugs were successfully studied using cyclic voltammetry (CV), square wave voltammetry (SWV), differential voltammetry (DPV) and steady state amperometry under aerobic conditions. Very good detection limits were obtained for the standard solutions of TB drugs and were found to be in the micromolar range. The detection limit values for the individual TB drugs were 0.55 μM (isoniazid), 0.7 μM (ethambutol), 0.054 μM (pyrazinamide) and 0.05 μM (rifampicin). The detection limit results showed that the nanobiosensors were more sensitive and suitable for the determination of the respective drugs in plasma and serum.

Philosophiae Doctor - PhD / This study firstly reports the development and characterization of PVP-AgNPs, PANSA and PVPAgNPs/ PANSA nanocomposite on gold. AFM and TEM analyses revealed highly electroactive nanocomposites whose morphogy and properties were essential for the immobilization of CYP2E1. Secondly, the development and characterization of Au/PVPAgNPs/ PANSA/CYP2E1, Au/PVP-AgNPs/PANSA/SA-CYP2E1 and Au/PVPAgNPs/ PANSA/EG-CYP2E1 nanobiosensors are reported. AFM studies displayed globular morphologies with large roughness for the enzyme modified electrodes as opposed to those electrodes without enzymes. Finally, the biotransformation of standard solutions of TB drugs (isoniazid, ethambutol, pyrazinamide and rifampicin) in pH 7.4, 0.1 M phosphate buffer solution is reported. The biotransformations of the TB drugs were successfully studied using cyclic voltammetry (CV), square wave voltammetry (SWV), differential voltammetry (DPV) and steady state amperometry under aerobic conditions. Very good detection limits were obtained for the standard solutions of TB drugs and were found to be in the micromolar range. The detection limit values for the individual TB drugs were 0.55 μM (isoniazid), 0.7 μM (ethambutol), 0.054 μM (pyrazinamide) and 0.05 μM (rifampicin). The detection limit results showed that the nanobiosensors were more sensitive and suitable for the determination of the respective drugs in plasma and serum. / South Africa

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No. of bitstreams: 1 adrianaferreirafaria.pdf: 20849316 bytes, checksum: 511836cab839ebb39105bd682c987241 (MD5) Previous issue date: 2010-08-13 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo principal da tese em questão foi o desenvolvimento, otimização e validação de metodologias analíticas para análise de formulações farmacêuticas utilizadas no tratamento da tuberculose, as quais contêm como princípio ativo etambutol (ETB), isoniazida (ISO), rifampicina (RIF) e pirazinamida (PIR), isolados ou em associação. Inicialmente, duas metodologias analíticas para análise de ETB em comprimidos foram desenvolvidas: a primeira permitiu a análise simultânea de ETB e da impureza 2-amino-1-butanol por eletroforese capilar de zona (CZE) utilizando um eletrólito de corrida contendo 60,0 mmol L-1 de tampão ácido acético/acetato de sódio e 5,0 mmol L-1 de Cu2+, polaridade normal (+25 kV) e detecção UV em 262 nm. A segunda foi realizada por espectrofotometria com diluição dos padrões e amostras em 5,0 mmol L-1 de tampão ácido acético/acetato de sódio e 0,5 mmol L-1 de Cu2+ e detecção UV em 262 nm. A formação do complexo CuETB foi necessária em ambas as metodologias desenvolvidas, uma vez que ETB apresenta baixa absortividade molar. Algumas figuras de mérito, tais como, linearidade, repetitividade, exatidão, limite de detecção e limite de quantificação foram avaliadas para as duas metodologias. Os dois métodos foram comparados e não apresentaram diferenças significativas no intervalo de 95% usando o teste t não pareado com variância agrupada. Em um segundo momento, um novo método para análise simultânea de dose fixa combinada (DFC), contendo ETB, ISO, RIF e PIR por CZE com detecção UV foi desenvolvido, otimizado e validado. A condição experimental consistiu em um eletrólito contendo 50,0 mmol L-1 de tampão ácido acético/acetato de sódio e 12,5 mmol L-1 de Cu2+ e polaridade normal (+22 kV). Essa metodologia foi aplicada com sucesso na análise de 2-DFC (ISO e PIR) em comprimidos e 4-DFC (ETB, ISO, RIF e PIR) em sache. Finalmente, uma metodologia por CZE utilizando detecção UV para a análise simultânea de ISO, suas impurezas e produtos de degradação, como o ácido isonicotínico, isonicotinato de etila, 4-cianopiridina e isonicotinamida foi otimizada. A condição experimental consistiu em um eletrólito contendo 50,0 mmol L-1 de tampão ácido acético/acetato de sódio e 12,5 mmol L-1 de Cu2+, polaridade normal (+20 kV) e detecção UV em 270 nm. É importante ressaltar que planejamentos de experimentos, tais como, planejamento fatorial completo 32 e Box-Behnken 33 foram utilizados como ferramenta auxiliar no desenvolvimento e otimização das metodologias analíticas (CZE e espectofotométrica) e na avaliação da robustez para a análise de 4-DFC. / The main focus of this thesis was the development, optimization and validation of analytical methodologies for analysis of pharmaceutical preparations used for tuberculosis treatment, which contain as active ingredients, ethambutol (ETB), isoniazid (ISO), rifampicin (RIF) and pyrazinamide (PYR) isolated or in association. Two analytical methodologies for ETB analysis in tablets were developed initially: the first one took into account the capillary zone electrophoresis (CZE) approach for simultaneous analysis of ETB and its impurity 2-amino-1-butanol using an electrolyte consisting of 60.0 mmol L-1 of acetic acid/acetate buffer, 5.0 mmol L-1 of Cu2+, under normal polarity (+25 kV) and UV detection at 262 nm. The second one was performed by spectrophotometry using 5.0 mmol L-1 of acetic acid/acetate buffer and 0.5 mmol L-1 of Cu2+ for standards and sample dilutions under UV detection at 262 nm. The CuETB complex was necessary for the two methodologies, since ETB presents low molar absorptivity. Some merit figures such as linearity, repeatability, accuracy, limit of detection and limit of quantification were evaluated for both methodologies. These methodologies were compared and they did not present significant differences at the 95% confidence level using the parametric independent sample t test. In a second phase a novel method for the simultaneous analysis of fixed dose combination (FDC) containing ETB, ISO, RIF and PYR by CZE under UV detection was developed, optimized and validated. The experimental condition optimized consisted of an electrolyte containing 50.0 mmol L-1 of acetic acid/acetate buffer and 12.5 mmol L-1 of Cu2+ under normal polarity (+22 kV). This methodology was successfully applied to the analysis of 2-FDC (ISO and PYR) in tablet samples and 4-FDC (ETB, ISO, RIF and PYR) in a sachet sample. Finally, a CZE methodology using UV detection for simultaneous analysis of ISO, its impurities and degradation products such as isonicotinic acid, ethyl isonicotinate, 4-cyanopyridine and isonicotinamide was ptimized. The optimized experimental condition consisted of an electrolyte containing 50.0 mmol L-1 of acetic acid/acetate buffer and 12.5 mmol L-1 of Cu2+ under normal polarity (+20 kV) and UV detection at 270 nm. It is important to stress that design of experiment such as 32 full factorial design and 33 Box-Behnken design were used as auxiliary tools in the development and optimization of the analytical methodologies (CZE and spectrophotemetric) and robustness evaluation for 4-FDC analysis.