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DESENVOLVIMENTO E VALIDAÇÃO DE METODOLOGIA PARA AVALIAÇÃO DE RUPATADINA POR CROMATOGRAFIA LÍQUIDA E ELETROFORESE CAPILAR / DEVELOPMENT AND VALIDATION OF METHODOLOGY FOR THE EVALUATION OF RUPATADINE BY LIQUID CHROMATOGRAPHY AND CAPILLARY ELECTROPHORESISNogueira, Daniele Rubert 12 March 2009 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Rupatadine is a second generation antihistamine H1, from the pyperidinic group, which inhibits both the histamine and platelet activating factor effects, and is clinically used for the treatment of allergic rhinitis and chronic urticaria. The methods for the evaluation of rupatadine in pharmaceutical products were developed and validated in the present work. The reversed-phase liquid chromatography (RP-LC) analysis was carried out using a Gemini C18
column (150 mm x 4.6 mm), maintained at 30 oC. The mobile phase consisted of ammonium acetate buffer 0.01 M, pH 3.0 with 0.05% of 1-heptanosulfonic acid/acetonitrile (71.5:28.5 v/v), run at a flow rate of 1.0 mL/min with detection at 242 nm. The chromatographic separation was obtained within 7 min and it was linear in the concentration range of 0.5-400 μg/mL (r2=0.9999). The capillary electrophoresis method was developed and validated, using the micellar electrokinetic chromatography (MEKC) as the separation mode, and nimesulide as internal standard (IS). The analysis were performed on a fused-silica capillary (50 μm id,
effective length, 40 cm), maintained at 35ºC, using electrolyte solution consisted of 15 mM borate buffer and 25 mM anionic detergent SDS solution at pH 10, with detection by photodiode array detector set at 205 nm. The injection was performed using the hydrodynamic mode at 50 mbar for 5 s, and a constant voltage of 25 kV was applied during the analysis. The electrophoretic separation was obtained within 6 min and it was linear in the oncentration range of 0.5-150 μg/mL (r2=0.9996). The procedures were validated evaluating parameters such as the specificity, linearity, precision, accuracy, limits of detection and quantitation, robustness, and system suitability test, giving results within the acceptable range. The proposed methods were applied for the analysis of pharmaceutical products, showing significant correlation (P>0.05) of the results. Therefore, the procedures can be applied to improve the quality control of pharmaceutical products and to assure the safety and
therapeutic efficacy of the drug. / A rupatadina é um anti-histamínico H1 de segunda geração pertencente ao grupo piperidínico, que inibe os efeitos da histamina e do fator ativador plaquetário, sendo utilizada
clinicamente no tratamento de rinite alérgica e urticária crônica. No presente trabalho foram desenvolvidos e validados métodos para avaliação de rupatadina em produtos farmacêuticos. As análises por cromatografia líquida em fase reversa (CL-FR) foram realizadas utilizando coluna Gemini C18 (150 mm x 4,6 mm), mantida a 30 oC. A fase móvel foi composta de tampão acetato de amônio 0,01 M, pH 3,0 com 0,05% de ácido 1-heptanosulfônico/acetonitrila (71,5:28,5, v/v), eluída na vazão de 1,0 mL/min com detecção no ultravioleta a 242 nm. A separação cromatográfica foi obtida no tempo de 7 min, sendo linear na faixa de concentração de 0,5-400 μg/mL (r2=0,9999). Paralelamente, desenvolveu-se e validou-se método por eletroforese capilar, utilizando modo de separação por cromatografia eletrocinética micelar (MEKC) e nimesulida como padrão interno (PI). Executaram-se as
análises em capilar de sílica fundida (50 μm id, comprimento efetivo de 40 cm), mantido a 35ºC, utilizando solução eletrolítica composta de tampão borato 15 mM e tensoativo aniônico SDS 25 mM, pH 10, com detecção no ultravioleta a 205 nm. A injeção foi realizada no modo hidrodinâmico a 50 mbar durante 5 s e voltagem constante de 25 kV foi aplicada durante as análises. A separação eletroforética foi obtida em 6 min, sendo linear na faixa de concentração de 0,5-150 μg/mL (r2=0,9996). Os procedimentos foram validados, avaliando-se os parâmetros de especificidade, linearidade, precisão, exatidão, limite de detecção e quantificação, robustez e teste de adequabilidade do sistema, cujos resultados cumpriram os requisitos preconizados. Os métodos propostos foram aplicados na análise de produtos farmacêuticos, demonstrando correlação significativa dos resultados (P>0,05). Desse modo, estabeleceram-se procedimentos que podem ser aplicados para aprimorar o controle da qualidade de medicamentos, bem como garantir a segurança e eficácia no uso terapêutico.
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Rejection and critical flux of calcium sulphate in a ceramic titanium dioxide nanofiltration membraneAhmed, Amer Naji January 2013 (has links)
This thesis describes the rejection efficiency and the fouling behaviour of calcium sulphate solutes in a 1 nm tubular ceramic titanium dioxide nanofiltration membrane. Calcium sulphate is considered as one of the greatest scaling potential inorganic salts that responsible for membrane fouling which represents a main challenge in the expansion of membrane processes for desalination of brackish and saline water. The surface charge type and magnitude for the composite amphoteric TiO_2 membrane were characterised using streaming potential measurements. Electrokinetic membrane experiments were conducted in a background electrolyte comprising 0.01 M (NaCl). The zeta potential was estimated from the measured streaming potential using the Helmoholtz-Smoluchowski equation and the surface charge density was subsequently calculated using the Gouy-Chapman and Graham equations. The experimental results showed that the membrane was negatively charged at neutral pH and its iso-electrical point (i.e.p) was at pH of 4.0. The rejection behaviour of calcium sulphate at three different initial concentrations (0.001, 0.005 and 0.01 M) were investigated compared to other naturally occurring minerals (NaCl, Na_2 SO_4, CaCl_2) in single salt solutions. The rejection experiments were conducted at five different applied trans-membrane pressures ranged from 1.0 to 5.0 bars. Salt retention measurements showed that the rejection sequence was R (CaSO_4) > R (Na_2 SO_4) > R (CaCl_2) > R (NaCl). This rejection sequence behaviour showed an inverse relationship with the diffusion coefficients of the four salts. The salt with the lowest diffusion coefficient (CaSO_4) showed the highest rejection (43.3%), whereas that with the highest diffusion coefficient showed the lowest rejection. The rejection of calcium sulphate solution at saturation concentration was also conducted after a suspension solution of 0.015 M (CaSO_4) was prepared and filtered. The ionic analysis for calcium sulphate permeates indicated that, for the negatively charged TiO_2 membrane, the rejection for bivalent anion (SO_4^(2-) ) was higher than that of the bivalent cation (Ca^(2+) ).The critical flux (CF) experiments were carried out at six trans-membrane pressure ranged from 1.0 to 6.0 bars to identify the form and the onset of calcium sulphate fouling (as gypsum) using different concentrations below saturation concentration (0.001, 0.005, 0.01 M) and at saturation concentration. Two different flux-pressure techniques have been applied and compared to determine the critical flux values; these are: step by step technique and standard stepping technique. The obtained critical flux results from both measuring techniques (for all the four sessions) confirmed that the critical flux was reached and exceeded. The present work indicated that the resulting critical flux values from both measuring procedures were decreased as the ionic strengths of the calcium sulphate solutes were increased. A mathematical model has been proposed to identify the key parameters that affect the transport performance inside the TiO_2 nanofiltration membrane. The original Donnan steric pore model (DSPM) was used to simulate the rejection of 0.01 M sodium chloride as a reference solution. The membrane effective pore radius was estimated using two different transport models, both of these models depend on the permeation test of uncharged solute (glucose). The Donnan potential was determined based on the membrane effective fixed charge density which was determined by supposing that the membrane surface charge was uniformly distributed in the void volume of cylindrical pores. The theoretical rejection of NaCl solute for the present DSPM model was found to be in agreement with the experimental data.
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Nelineární jevy v elektrokinetické chromatografii / Nonlinear phenomena in electrokinetic chromatographyDovhunová, Magda January 2019 (has links)
Capillary electrophoresis often uses complexing agents since the interaction between the analyte and the complexing agent can result in achieving or improving the separation. Examples of such methods can be electrokinetic chromatography or affinity capillary electrophoresis (ACE). ACE is used to determine the complexing parameters. In case of chiral separation, this issue gets complicated, since the parameters of the two analytes (enantiomers) are not completely independent to one another. Therefore, a procedure has been proposed in this thesis, that should always be used to evaluate the complexing parameters of two enantiomers. Statistical evaluation of these parameters was assessed as well. This work also proposes a method that allows to determine the relative migration order of two enantiomers in two different complexing separation systems. The mathematical description of electrophoresis is based on continuity equations, that are inherently nonlinear. However, these equations can be linearized to obtain an approximate analytical solution. There was recently presented a generalized model, that enables inclusion of complete complexing equilibria in the theoretical description of electromigration. Thus, various phenomena, including nonlinear ones, associated with complexation can be predicted. This...
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Electrodialytic Remediation of PFAS-Contaminated SoilNiarchos, Georgios January 2018 (has links)
Per- and polyfluoroalkyl substances (PFASs) are a group of anthropogenic aliphatic compounds, widelyknown for their environmental persistence and toxicity to living beings. While they are ubiquitous in theenvironment, interest has been focused on contaminated soil, which can act as a primary recipient andsource of groundwater contamination. Electrokinetic technology is based on the movement of ionsunder the effect of an electric field. This could be a promising remediation solution, since PFASs areusually present in their anionic form. The contaminants can then be concentrated towards the anode,thus reducing a plume’s volume and possibly extracting the substances from soil. The preliminary aimof the present study was to evaluate the potential of using electrodialysis for the remediation of PFAScontaminatedsoil for the first time. Experiments were run with natural contaminated soil samples,originating from a fire-fighting training site at Arlanda Airport, and at Kallinge, Sweden, as well as inartificially spikedsoil. Electrodes were placed in electrolyte-filled chambers and separated by the soilwith ion-exchange membranes for pH-control. In total, five experiments were conducted. Two differentsetups were tested, a typical 3-compartment EKR cell and a 2-compartment setup, to allow for pHincrease and facilitate PFAS desorption. Two different current densities were tested; 0.19 mA cm-2 and0.38 mA cm-2. After twenty-one days, soil was cut in ten parts lengthwise and triplicate samples wereanalysed for PFAS concentrations, with HPLC-MS/MS. Sixteen out of the twenty-six screened PFASswere detected above MDL in the natural soil samples. The majority of the detected PFASs showed apositive trend of electromigration towards the anode, under both current densities, with only longerchainedcompounds (c>8) being immobile. This can be attributed to the stronger sorption potential oflong-chained PFAS molecules, as has been reported in previous sorption studies. Mass balancedistribution for a high current density (0.38 mA cm-2) experiment revealed that 73.2% of Σ26PFAS wasconcentrated towards the anode, with 59% at the soil closer to the anode, 5.7% at the anion exchangemembrane and 8.5% at the anolyte. It also showed higher mobility for short-chained molecules (c≤6),as they were the only compounds to be extracted from soil and be concentrated in the anolyte. Highercurrent densities were not directly correlated with higher electromigration rates, as to the lack of massbalance data for the low current density experiments. Regardless, electrodialysis could be a viable optionfor PFAS soil remediation and further research to encourage the understanding of the migrationmechanism, as well as combination with other treatment methods is encouraged. / Per- och polyfluoralkylsubstanser (PFAS) är en grupp av antropogena alifatiska föreningar, allmäntkända för sin miljöpåverkan och toxicitet för levande varelser. Medan de är allestädes närvarande imiljön har intresset varit inriktat på förorenad mark, som kan fungera som primär mottagare och källatill grundvattenförorening. Elektrokinetisk teknik är baserad på jonernas rörelse under effekten av ettelektriskt fält. Detta kan vara en lovande lösningsmedel, eftersom PFAS är vanligtvis närvarande i sinanjoniska form. Föroreningarna kan sedan koncentreras mot anoden, vilket reducerar en plums volymoch eventuellt extraherar ämnena från jorden. Det preliminära målet med den föreliggande studien varatt utvärdera potentialen att använda elektrodialys för sanering av PFAS-förorenad jord för förstagången. Experimenten kördes med naturliga förorenade jordprover, härrörande från enbrandbekämpningsplats vid Arlanda flygplats, och i Kallinge, Sverige, samt i konstgjort spikedsol.Elektroder placerades i elektrolytfyllda kamrar och separerades av jorden med jonbytesmembran förpH-kontroll. Totalt genomfördes fem experiment. Två olika inställningar testades, en typisk 3-facksEKR-cell och en 2-facksinställning, vilket möjliggör pH-ökning och underlättar PFAS-desorption. Tvåolika strömtätheter testades; 0,19 mA cm-2 och 0,38 mA cm-2. Efter tjugo dagar skärs jorden i tio delari längdriktningen och trippelprover analyserades för PFAS-koncentrationer, med HPLC-MS / MS.Sexton av de tjugosex screenade PFAS: erna detekterades över MDL i de naturliga markproverna.Majoriteten av de upptäckta PFAS-värdena visade en positiv trend av elektromigration mot anodenunder båda strömtätheten, varvid endast längre kedjiga föreningar (c> 8) var immobila. Detta kanhänföras till den starkare sorptionspotentialen hos långkedjiga PFAS-molekyler, vilket har rapporteratsi tidigare sorptionsstudier. Massbalansfördelning för ett experiment med hög strömtäthet (0,38 mA cm-2) visade att 73,2% av Σ26PFAS koncentrerades mot anoden, med 59% vid jorden närmare anoden, 5,7%vid anjonbytarmembranet och 8,5% vid anolyten. Det visade också högre rörlighet för kortkedjigamolekyler (c≤6), eftersom de var de enda föreningarna som skulle extraheras från jord och koncentrerasi anolyten. Högre strömtätheter var inte direkt korrelerade med högre elektromigrationshastigheter,avseende bristen på massbalansdata för experimenten med låg strömtäthet. Oavsett elektrodialys kandet vara ett lönsamt alternativ för PFAS-markrening och ytterligare forskning för att uppmuntraförståelsen för migrationsmekanismen, liksom kombinationen med andra behandlingsmetoder främjas.
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METHOD DEVELOPMENT AND INVESTIGATION OF FLUORESCENT PHOSPHOINOSITIDE CELL SIGNALING PROPERTIES BY CAPILLARY ELECTROPHORESISQuainoo, Emmanuel W0bil 21 April 2010 (has links)
No description available.
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Electrokinetic flow in micro- and nano-fluidic componentsZheng, Zhi 19 November 2003 (has links)
No description available.
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Multiplexed Optofluidics for Single-Molecule AnalysisStott, Matthew Alan 01 April 2018 (has links)
The rapid development of optofluidics, the combination of microfluidics and integrated optics, since its formal conception in the early 2000's has aided in the advance of single-molecule analysis. The optofluidic platform discussed in this dissertation is called the liquid core anti-resonant reflecting optical waveguide (LC-ARROW). This platform uses ARROW waveguides to orthogonally intersect a liquid core waveguide with solid core rib waveguides for the excitation of specifically labeled molecules and collection of fluorescence signal. Since conception, the LC-ARROW platform has demonstrated its effectiveness as a lab-on-a-chip fluorescence biosensor. However, until the addition of optical multiplexing excitation waveguides, the platform lacked a critical functionality for use in rapid disease diagnostics, namely the ability to simultaneously detect different types of molecules and particles. In disease diagnostics, the ability to multiplex, detect and identify multiple biomarkers simultaneously is paramount for a sensor to be used as a rapid diagnostic system. This work brings optofluidic multiplexing to the sensor through the implementation of three specific designs: (1) the Y-splitter was the first multi-spot excitation design implemented on the platform, although it did not have the ability to multiplex it served as a critical stepping stone and showed that multi-spot excitation could improve the signal-to-noise ratio of the platform by ~50,000 times; (2) a multimode interference (MMI) waveguide which took the multi-spot idea and then demonstrated spectral multiplexing capable of correctly identifying multiple diverse biomarkers simultaneously; and, (3) a Triple-Core design which incorporates excitation and collection along multiple liquid cores, enabling spatial multiplexing which increases the number of individual molecules to be identified concurrently with the MMI waveguide excitation. In addition to describing the development of optical multiplexing, this dissertation includes an investigation of another LC-ARROW based design that enables 2D bioparticle trapping, the Anti-Brownian Electrokinetic (ABEL) trap. This design demonstrates two-dimensional compensation of a particle's Brownian motion in solution. The capability to maintain a molecule suspended in solution over time enables the ability to gain a deeper understanding of cellular function and therapies based on molecular functions.
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Physicochemical and Biopharmaceutical Characterisation of Small Drug Molecules by Capillary ElectrophoresisÖrnskov, Eivor January 2004 (has links)
<p>Capillary Electrophoresis (CE) was explored as a means for physicochemical and biopharmaceutical characterisation of small drug molecules. Special attention was paid to the characterisation of acid-base and lipophilic properties of drug compounds by analysing their migration behaviour in different CE systems. The thesis comprises an overview of the field together with separate studies on the different topics.</p><p>The utility of CE for the determination of pK<sub>a</sub> of labile drug compounds was investigated. A general methodology was developed comprising key steps such as the use of a stabilising sample diluent, electromigration injection, and analyte characterisation by UV-Vis spectroscopy. The methodology was successfully applied for two sets of drug compounds, labile at low and high pH, respectively.</p><p>CE was also evaluated for experimental modelling of passive intestinal membrane permeability by studying analyte migration in liposomal, microemulsion and micellar electrolytes. Good correlation is reported between CE migration and Caco-2 cell absorption estimates and for in vitro inhibition of thrombin. Interestingly, a slightly better correlation was obtained for liposomal electrolytes.</p><p>The utility of liposomes in CE was further extended by developing a novel procedure for immobilising liposomes inside fused silica capillaries. This approach enabled direct on-line coupling of liposome CE to high sensitivity mass spectrometry. The utility of liposome-coated capillaries is demonstrated for estimating drug passive intestinal membrane permeability. Its use in biopharmaceutical drug profiling is discussed.</p><p>Utilising advanced molecular descriptors, commonly applied to in silico prediction of passive intestinal membrane permeability, migration of analytes in micellar CE systems could be well predicted. The novel approach was based on hierarchical multivariate analytics and use of molecular descriptors for both analytes and micellar media surfactants. Demonstrated results propose that the CE format could be useful to validate how representative molecular descriptors are for describing molecular behaviour in complex liquid media, e.g. physiological systems.</p>
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Physicochemical and Biopharmaceutical Characterisation of Small Drug Molecules by Capillary ElectrophoresisÖrnskov, Eivor January 2004 (has links)
Capillary Electrophoresis (CE) was explored as a means for physicochemical and biopharmaceutical characterisation of small drug molecules. Special attention was paid to the characterisation of acid-base and lipophilic properties of drug compounds by analysing their migration behaviour in different CE systems. The thesis comprises an overview of the field together with separate studies on the different topics. The utility of CE for the determination of pKa of labile drug compounds was investigated. A general methodology was developed comprising key steps such as the use of a stabilising sample diluent, electromigration injection, and analyte characterisation by UV-Vis spectroscopy. The methodology was successfully applied for two sets of drug compounds, labile at low and high pH, respectively. CE was also evaluated for experimental modelling of passive intestinal membrane permeability by studying analyte migration in liposomal, microemulsion and micellar electrolytes. Good correlation is reported between CE migration and Caco-2 cell absorption estimates and for in vitro inhibition of thrombin. Interestingly, a slightly better correlation was obtained for liposomal electrolytes. The utility of liposomes in CE was further extended by developing a novel procedure for immobilising liposomes inside fused silica capillaries. This approach enabled direct on-line coupling of liposome CE to high sensitivity mass spectrometry. The utility of liposome-coated capillaries is demonstrated for estimating drug passive intestinal membrane permeability. Its use in biopharmaceutical drug profiling is discussed. Utilising advanced molecular descriptors, commonly applied to in silico prediction of passive intestinal membrane permeability, migration of analytes in micellar CE systems could be well predicted. The novel approach was based on hierarchical multivariate analytics and use of molecular descriptors for both analytes and micellar media surfactants. Demonstrated results propose that the CE format could be useful to validate how representative molecular descriptors are for describing molecular behaviour in complex liquid media, e.g. physiological systems.
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Olmesartana medoxomila : validação de metodologia analítica, avaliação biofarmacêutica e análise polimórfica / Olmesartan medoxomil: validation of analytical methodology, biopharmaceutical evaluation, and polymorphic analysisBajerski, Lisiane January 2010 (has links)
O pró-fármaco olmesartana medoxomila (OLM) é um anti-hipertensivo representante da classe dos bloqueadores seletivos dos receptores da angiotensina II (BRA). No Brasil, encontra-se disponível sob a forma de comprimidos revestidos (Benicar®). Foi aprovado pelo FDA em 2002. Não existe monografia disponível para este fármaco em nenhum código oficial. Desse modo, este trabalho objetivou o desenvolvimento de métodos analíticos para quantificação da OLM na substância química de referência (SQR) e forma farmacêutica, estabelecer a cinética de dissolução in vitro para os comprimidos revestidos deste fármaco e por fim investigar a presença de diferentes estruturas polimórficas da SQR deste anti-hipertensivo. A determinação da faixa de fusão, a espectrofotometria na região do infravermelho (IV), assim como a espectroscopia de ressonância magnética nuclear (RMN) de 1H e 13C permitiram a identificação da SQR. Os métodos por espectrofotometria na região do ultravioleta (UV), cromatografia em camada delgada (CCD), cromatografia a líquido de alta eficiência (CLAE) e cromatografia capilar eletrocinética micelar (MECC) foram utilizados para análise qualitativa do fármaco no produto acabado. A determinação quantitativa foi realizada através do desenvolvimento e validação de método indicativo da estabilidade por CLAE e MECC, avaliando-se os parâmetros descritos pelas guias de validação como: especificidade, robustez, linearidade, limites de detecção e quantificação, precisão e exatidão. Determinou-se ainda, a intercambialidade dos mesmos, através de análise estatística por ANOVA (p = 0,05), e comprovou-se que ambos podem ser utilizados para análise qualitativa e quantitativa da OLM em matéria-prima e produto acabado. O teste de dissolução foi desenvolvido e validado de acordo com o guia proposto pelo USP Fórum, utilizando como meio de dissolução 900 ml de uma solução a 0,5% (p/V) de lauril sulfato de sódio pH 6,8, a 37 ± 0,5 °C, pás a 50 rpm e quantificação por CLAE e espectrofotometria na região do UV. A análise do teor de OLM dissolvida, realizada por ambos os métodos, não apresentou diferença estatística (p > 0,05). Os perfis de dissolução do Benicar®, medicamento referência, e do Olmetec®, outra formulação disponível no mercado, foram considerados semelhantes, após aplicação do método modelo-independente (f1 e f2) e eficiência de dissolução. Avaliou-se, também, a cinética de dissolução de ambas as formulações através da aplicação de métodos modelo-dependentes. Os perfis de dissolução do Benicar® e Ometec® foram descritos pelos modelos propostos por Hixson-Crowell e de ordem zero, respectivamente. Os valores calculados para t50% e t80%, obtidos através da aplicação da equação de ordem zero, foram semelhantes aos valores experimentais encontrados no perfil de dissolução de ambos os produtos. As técnicas de espectrofotometria por reflexão difusa no IV com transformada de Fourier (ATRFTIR), difração de raios-X de pó (XRPD), calorimetria exploratória diferencial (DSC), termogravimetria (TGA) e microscopia eletrônica de varredura (MEV) permitiram a identificação de uma forma amorfa e outra polimórfica da SQR da OLM, diferentes daquela descrita na literatura. Logo, de acordo com os resultados obtidos, todos os métodos propostos podem ser utilizados para no controle de qualidade da OLM em SQR e produto acabado. / The prodrug olmesartan medoxomil (OLM) is a selective angiotensin II receptor blocker (ARB). In Brazil, it is available as coated tablets (Benicar®). It was approved by FDA in 2002. There is no monograph available for this drug in any official code. According to this, the main purpose of this study was to develop a quality control analytical methodology for OLM in bulk material and dosage form, to establish in vitro dissolution kinetic for OLM coated tablets, and to investigate the crystalline behavior of OLM bulk material. The investigation of melting range and application of techniques such as infrared spectrophotometry (IR), as well as the 1H and 13C nuclear magnetic resonance (NMR) spectroscopy were used to identify OLM. Ultraviolet (UV) spectrophotometry, thin-layer chromatography (TLC), highperformance liquid chromatography (LC) and micellar electrokinetic chromatography (MEKC) were used for qualitative analysis of the drug in coated tablets. The quantitative determination was carried out through the development and validation of a stability-indicating LC and MEKC methods, evaluating the parameters described in the guidelines such as: specificity, robustness, linearity, detection and quantitation limits, precision, and accuracy. The results were compared statistically by ANOVA (p = 0.05), and no difference was found between them for both bulk material and coated tablets. A dissolution test was developed and validated according to the guideline proposed by the USP Forum, using 900 ml of dissolution medium containing 0.5% of sodium lauryl sulfate (w/V) pH 6.8, at 37 ± 0.5 °C, paddle at 50 rpm, and quantitation by LC and UV spectrophotometry. The resulting dissolution profiles did not show statistical difference (p > 0.05) between methods. The dissolution profiles of Benicar®, reference formulation, and Olmetec®, another commercial formulation available, were considered similar, using model independent (f1, f2, and dissolution efficiency) methods. The dissolution kinetic of both formulations, using model dependent approaches, revealed that Benicar® followed the Hixson-Crowell model, while Olmetec® the zero-order model. The calculated values of t50% and t80%, obtained from zero-order equation, were similar of experimental values found in the dissolution profile for both products. The attenuated total reflectance Fourier transformed infrared (ATR-FTIR) spectrophotometry, along with differential scanning calorimetry (DSC), thermogravimetry (TG), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM) allowed to identify one amorphous and other polymorphic forms of OLM. According to the obtained results, all proposed methods could be used in the quality control of OLM bulk material and coated tablets.
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