300 research outputs found

    Mercury and selenium binding biomolecules in terrestrial mammals (Cervus elaphus and Sus scrofa) from a mercury exposed area

    Get PDF
    Acknowledgements The authors are grateful to Junta de Comunidades de Castilla-La Mancha (PCC-05-004-2, PAI06-0094, PCI-08-0096, PEII09-0032-5329) and the Ministerio de Economía y Competitividad (CTQ2013-48411-P) for financial support. M.J. Patiño Ropero acknowledges the Junta de Comunidades de Castilla-La Mancha for her PhD. fellowship.Peer reviewedPostprin

    Derivative spectrophotometric analysis of benzophenone (as an impurity) in phenytoin

    Get PDF
    Three simple and rapid spectrophotometric methods were developed for detection and trace determination of benzophenone (the main impurity) in phenytoin bulk powder and pharmaceutical formulations. The first method, zero-crossing first derivative spectrophotometry, depends on measuring the first derivative trough values at 257.6 nm for benzophenone. The second method, zero-crossing third derivative spectrophotometry, depends on measuring the third derivative peak values at 263.2 nm. The third method, ratio first derivative spectrophotometry, depends on measuring the peak amplitudes of the first derivative of the ratio spectra (the spectra of benzophenone divided by the spectrum of 5.0 μg/mL phenytoin solution) at 272 nm. The calibration graphs were linear over the range of 1-10 μg/mL. The detection limits of the first and the third derivative methods were found to be 0.04 μg/mL and 0.11 μg/mL and the quantitation limits were 0.13 μg/mL and 0.34 μg/mL, respectively, while for the ratio derivative method, the detection limit was 0.06 μg/mL and the quantitation limit was 0.18 μg/mL. The proposed methods were applied successfully to the assay of the studied drug in phenytoin bulk powder and certain pharmaceutical preparations. The results were statistically compared to those obtained using a polarographic method and were found to be in good agreement

    Spectrofluorimetric determination of sertraline in dosage forms and human plasma through derivatization with 9-fluorenylmethyl chloroformate

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive-compulsive, panic and social anxiety disorders in both adults and children. A survey of the literature reveals that most of the reported methods are either insufficiently sensitive or tedious and require highly sophisticated and dedicated instrumentation. The proposed method is considered to be specific for determination of SER in presence of its metabolite (deaminated form).</p> <p>Results</p> <p>A sensitive, simple and specific spectrofluorimetric method was developed for the determination of sertraline (SER) in pharmaceutical formulations and biological fluids. The method is based on its reaction with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer of pH 8.0 to yield a highly fluorescent derivative peaking at 315 nm after excitation at 265 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence concentration plot was rectilinear over the range of 0.05-1.0 μg mL<sup>-1 </sup>with a lower detection limit of 5.34 × 10<sup>-3 </sup>μg mL<sup>-1 </sup>and limit of quantitation of 0.016 μg mL<sup>-1</sup>.</p> <p>Conclusions</p> <p>The proposed method was successfully applied to the analysis of commercial tablets and the results obtained were in good agreement with those obtained using the reference method. Furthermore, the method was applied for the determination of SER in spiked and real human plasma. The mean % recovery (n = 3) was 94.33 ± 1.53 and 92.00 ± 2.65, respectively. A proposal of the reaction pathway was postulated.</p

    Secuencias gráficas Paleolítico-Postpaleolítico en la Sierra de San Pedro. Tajo internacional. Cáceres

    Get PDF
    The UAH team is developing successive projects of heritage evaluation in the International Tagus, focused on the megalithic culture. Our surveys, based on the theoretical statement of a predictive model that considers the presence of outdoor paintings, make the Sierra de San Pedro one of the most important schematic painting groups of the Iberian Peninsula. Its parallel development to the sites with outdoor engravings in the International Tagus draws a complex set of symbols with a major role in the definition of megalithic territories. The identification of Palaeolithic figures coincides with similar recurrences documented in outdoor sites of the western peninsula, pointing to the resort to the past as one of the arguments of vindication and use of traditional territories.El equipo de la UAH viene desarrollando sucesivos proyectos de valoración patrimonial en el Tajo Internacional centrados en la cultura megalítica. Nuestras prospecciones a partir de la exposición teórica de un modelo predictivo que considera la presencia de pinturas al aire libre, hacen de la Sierra de San Pedro uno de los más importantes conjuntos de la pintura esquemática de la Península Ibérica. Su desarrollo paralelo a los yacimientos con grabados al aire libre del Tajo Internacional dibuja un complejo entramado de símbolos con un importante papel en la definición de los territorios megalíticos. La identificación de figuras paleolíticas coincide con recurrencias similares documentadas en los yacimientos al aire libre del occidente peninsular, apuntando al recurso al pasado como uno de los argumentos de reivindicación y uso de territorios tradicionales

    A review of analytical methods for the determination of four new phosphodiesterase type 5 inhibitors in biological samples and pharmaceutical preparations

    Get PDF
    The introduction of oral phosphodiesterase type 5 inhibitor therapy in 1998 revolutionized the treatment of erectile dysfunction. Erectile dysfunction is the most common sexual problem in men. It often has a profound effect on intimate relationships and quality of life. The analysis of pharmaceuticals is an important part of the drug development process as well as for routine analysis and quality control of commercial formulations. Whereas the determination of sildenafil citrate, vardenafil and tadalafil are well documented by a variety of methods, there are few publications about the determination of udenafil, lodenafil carbonate, mirodenafil and avanafil. The paper presents a brief review of the action mechanism, adverse effects, pharmacokinetics and the most recent analytical methods that can determine drug concentration in biological matrices and pharmaceutical formulations of these four drugs.A introdução da terapia oral com inibidores da fosfodiesterase tipo 5, em 1998, revolucionou o tratamento da disfunção erétil. A disfunção erétil é o problema sexual mais comum em homens. Muitas vezes tem um efeito profundo nas relações íntimas e na qualidade de vida. A análise de produtos farmacêuticos é uma parte importante do processo de desenvolvimento de fármacos, bem como para a análise de rotina e controle de qualidade das formulações comerciais. Enquanto a determinação do citrato de sildenafila, vardenafila e tadalafila está bem documentada por uma variedade de métodos, existem poucas publicações sobre a determinação de udenafila, carbonato de lodenafila, mirodenafila e avanafila. O artigo apresenta uma breve revisão do mecanismo de ação, efeitos adversos, farmacocinética e os mais recentes métodos analíticos, que podem determinar a concentração do fármaco em matrizes biológicas e formulações farmacêuticas destes quatro fármacos

    Food colorants: Challenges, opportunities and current desires of agro-industries to ensure consumer expectations and regulatory practices

    Full text link
    corecore