Submitted by Leticia Schettini (leticia@ufrrj.br) on 2016-10-04T13:00:01Z No. of bitstreams: 1 2016 - Thais Paes Ferreira.pdf: 1131707 bytes, checksum: c98267296d6293f703188fe1291622db (MD5) / Made available in DSpace on 2016-10-04T13:00:01Z (GMT). No. of bitstreams: 1 2016 - Thais Paes Ferreira.pdf: 1131707 bytes, checksum: c98267296d6293f703188fe1291622db (MD5) Previous issue date: 2016-05-11 / Fluazuron is a benzoylphenylurea acarine growth inhibitor that is marketed for the control of cattle tick. Although the growth regulators are widely studied class, the number of papers describing analytical methods for determining the fluazuron in plasma samples is reduced. The development of a simple and fast analytical method for quantifying fluazuron in bovine plasma by HPLC-UV enables the evaluation of drug plasma profile and can be applied on bioavailability analysis of formulations containing fluazuron. In recent years there has been a technological breakthrough for chromatographic instrumentation, providing rapid, robust and sensitive methods, but the pretreatment of the sample stage becomes the limiting factor in this process. New extraction methods have been developed, however are often complex, expensive methods and are not as sophisticated to handle complex matrices, such as plasma. The aim of this study was a comparative study of three extraction methods: LLE, SPE and matrix solid phase dispersion (MSPD). Pooled plasma samples were used as biological material, partly as raw samples and partly spiked with concentrations of fluazuron. For each extraction method (with exception of DMFS) was conducted using various solvents (ethyl acetate, dichloromethane, diethyl ether, hexane and acetonitrile) in order to evaluate the best extractor solvent. After the extractions the samples were concentrated and analyzed by HPLC/UV. The chromatographic separation was achieved on Kromasil C18 column preceded by guard column of matching chemistry, with mobile phase of acetonitrile: water (80:20, v/v) at flow rate of 1.0 mL/min. The comparative analysis of the extraction procedures was based on selectivity, precision and accuracy of the method. Results showed that LLE not presented accuracy (< 80 and >120%) and precision (CV > 15%) with any solvent tested. SPE method showed good accuracy (80-120%) and precision (CV < 15%) for ethyl acetate, dichloromethane and diethyl ether. MSPD method using ethyl acetate solvent showed good accuracy and precision. However, SPE also allows a lower solvent consumption and shorter analysis time. The validation of the analytical method showed linearity, selectivity, precision, accuracy and, absence matrix effects and residual, thus proving it as suitable for routine analysis; This method showed to be an important investigative tool in the analysis of fluazuron plasma concentration in cattle. Fluazuron topical administration in bovine reached the systemic circulation (Cmax=62,8 ng/mL), was absorbed (tmax=48 hs), while maintaining quantifiable blood plasma levels for up to 14 days after the treatment with a 2,5 mg/Kg dosage. / Fluazuron ? um inibidor do crescimento da classebenzoilfenilur?ia, sendo comercializado para o controle de carrapatos do gado. Embora a classe de reguladores de crescimento sejam amplamente estudada, o n?mero de artigos que descrevem os m?todos anal?ticos para a determina??o do fluazurom em amostras de plasma ? escasso. O desenvolvimento de um m?todo anal?tico simples e r?pido para quantificar fluazuron em plasma bovino por CLAEUV permite a avalia??o do perfil plasm?tico do f?rmaco e pode ser aplicado na an?lise de biodisponibilidade de formula??es contendo fluazurom. Nos ?ltimos anos, tem acontecido um avan?o tecnol?gico para a instrumenta??o cromatogr?fica, proporcionando m?todos r?pidos, eficazes e sens?veis, mas a etapa de pr?-tratamento da amostra torna-se o fator limitante neste processo. Novos m?todos de extra??o t?m sido desenvolvidos, no entanto, muitas das vezes s?om?todos complexos, caros e n?o t?o sofisticados para matrizes complexas como o plasma. O objetivo deste estudo foi um estudo comparativo de tr?s m?todos de extra??o: extra??o l?quido-l?quido (ELL), extra??o em fase s?lida (EFS) e dispers?o de matriz em fase s?lida (DMFS). Ums mistura de amostras de plasma foi utilizada como material biol?gico, uma parte como amostra bruta e outra parcialmente enriquecida com concentra??es de fluazuron. Para cada m?todo de extra??o (exceto DMFS) foram analisadosdiversos solventes (acetato de etila, diclorometano, ?ter diet?lico, hexano e acetonitrila), a fim de avaliar o melhor solvente extrator. Ap?s as extra??es, as amostras foram concentradas e analisadas por CLAE/UV. A separa??o cromatogr?f ica foi obtida na coluna Kromasil C18 precedida de pr?-coluna de fase qu?mica correspondente, com fase m?vel de acetonitrila: ?gua (80:20, v/v) a um fluxo de 1,0 mL /min. A an?lise comparativa dos procedimentos de extra??o foi baseada na seletividade, precis?o e exatid?o do m?todo. Os resultados mostraram que a precis?o ELL n?o apresentou exatid?o (<80 e> 120%) e precis?o (CV> 15%) com nenhum dos solventes analisados. O m?todo EFS mostrou boa exatid?o (80-120%) e precis?o (CV <15%) para o acetato de etila, diclorometano e ?ter diet?lico. O m?todo de DMFS utilizando o solvente acetato de etila mostrou boa exatid?o e precis?o. No entanto, a EFS tamb?m permite um menor consumo de solventes e um tempo curto de an?lise; A valida??o do m?todo anal?tico mostrou linearidade, seletividade, precis?o, exatid?o e, aus?ncia de efeitos de matriz e residual, demonstrando-se adequado para an?lises de rotina; Este m?todo mostrou-se uma ferramenta de investiga??o importante na an?lise de concentra?? plasm?tica em bovinos. Fluazuron administrado por via t?pica em bovinos atingiu a circula??o sist?mica (Cmax = 62,8 ng /ml) e foi absorvido (Tm?x = 48 Hs), se mantendo quantificav?l em n?veis plasm?ticos por at? 14 dias ap?s o tratamento com uma dosagem de 2,5 mg / kg.