Influencia de agentes Tensioactivos sobre la velocidad de disolución de comprimidos

El presente trabajo ha sido realizado con una Beca del Fondo Lepetit para ayuda y fomento de la investigación médico-farmacéutica. Agradecemos sinceramente dicha concesión merced a la cual ha sido posible su elaboración. Ha sido presentado al I Congreso Nacional de Biofarmacia y Farmacocinética. Barcelona. Mayo 1975.En el presente trabajo se estudia la infiuencia que los agentes tensioactivos ejercen sobre la velocidad de disolución de comprimidos, y por tanto sobre su disponibilidad "in vitro". Para ello se han elaborado siete series de comprimidos de fenilbutazona en los que se han incluido Tween 80 Y Lauril sulfato sódico en diversas etapas de su fabricación. Se han sometido a ensayos de disolución utilizando un dispositivo automático de flujo continuo, y se ha observado un gran aumento de la misma, mayor en el caso del Laurilsulfato sódico, y especialmente cuando el tensioactivo va adicionado al aglutinante. La valoración cuantitativa de fenilbutazona en les comprimidos y en la disolución final permite apreciar la total liberación de la sustancia medicamentosa.In the present work we study the influence of "surfactants" on the dlssolution speed nf tabIets, thus, on its availability "in vitro". We have elaborated seven series of Phenylbutazone tablets with Tween 80 and sodium Lauryl Sulfate added at diff.er,ent steps of its manufactu ringo They were subjeted to dissolution tests using an automatic disposi tive of continuous flux, and a great increase of ,H was observed, greater With Sodlum Lauryl Sulfate and specially when the surfactants was added to the binding agent. The quantitative appraisemeni of Phenybutazone, in the tablets and final dissolution allows to stimate the total release of the drug.Fondo Lepeti

Biodisponibilidad de corticoides fluorados en preparaciones semisólidas

Trabajo presentado al II Congreso Nacional de Biofarmacia y Farmacocinética. Madrid, 16-18 mayo de 1977.En el presente trabajo se ha realizado un estudio de la biodisponibillidad de tres corticoides fluorados contenidos en diversas preparaciones semisólidas. Las sustancias medicamentosas objeto de ensayo, Flupamesona, Flupredniliden y Formocortal, se han incluido en dos excipientes usuales, el Hydrophilic Ointment y el de Polyethileneglycol, ensayándose además tres formulaciones comerciales que los contienen. Las pruebas efectuadas en todas ellas son de dos tipos: - "In vitro", según la técnica de cesión en miristato de isopropilo. - "In vivo", por el procedimiento de vasocontricción o emblanquecimiento de McKENZIE y STOUGHTON. De los resultados obtenidos se comprueba que el Hydrophilic Ointment presenta mejores características de cesión, superiores incluso a las formulaciones del mercado farmacéutico. Asimismo, de los tres corticoides ensayados, el Formocortal presenta mayor actividad vaso constrictora, siguiéndole el Fluprednyliden, y encontrándose en último lugar la Flupamesona.In the present work a study on the bioavailibity of three fluorate corticoids contained in various semisolid preparations have been carried out. The medicinal substance submítted to the assay, Flupamesona, Fluprednyliden y Formocortal, have been included in two usual excipients, the Hydrophilic Ointment and the Polyethyleneglycol. Furthermore, three commercial formulations in whích they are contained, were assayed. The test carried out in all of them are of two kinds: - "In vitro", following the technique of cession in isopropyl myristate. - "In vivo", foUowing the procedure of vasoconstricción and bleaching of McKENZIE and STOUGHTON. From the results obtained we verify that the Hydrophilic Ointment shows better properUes of cession, even better than the formulations which are available in the pharmaceutical market. Likewise, from the three corticoids assayed, the Fomocortal shows a greater vasoconstricting activity, being followed by the Fluprednyliden; the Flupamesona 1s found in the last position

Cellulose Nanofiber-Based Aerogels from Wheat Straw: Influence of Surface Load and Lignin Content on Their Properties and Dye Removal Capacity

Water pollution is one of the most serious problems worldwide. Nanocellulose-based aerogels usually show excellent adsorption capacities due to their high aspect ratio, specific surface area and surface charge, making them ideal for water purification. In this work, (ligno)cellulose nanofibers (LCNFs/CNFs) from wheat straw residues were obtained using two types of pre-treatments: mechanical (Mec) and TEMPO-mediated oxidization (TO), to obtain different consistency (0.2, 0.4, 0.6 and 0.8) bioaerogels, and their adsorption capacities as dye removers were further studied. The materials were characterized in terms of density, porosity and mechanical properties. An inversely proportional relationship was observed between the consistencies of the aerogels and their achieved densities. Despite the increase in density, all samples showed porosities above 99%. In terms of mechanical properties, the best results were obtained for the 0.8% consistency LCNF and CNF-Mec aerogels, reaching 67.87 kPa and 64.6 kPa for tensile strength and Young’s modulus, respectively. In contrast, the adsorption capacity of the aerogels was better for TEMPO-oxidized aerogels, reaching removal rates of almost 100% for the CNF-TO5 samples. Furthermore, the residual lignin content in LCNF-Mec aerogels showed a great improvement in the removal capacity, reaching rates higher than 80%, further improving the cost efficiency of the samples due to the reduction in chemical treatments

Un proyecto audiovisual sobre el equilibrio químico para el máster en formación del profesorado de educación secundaria

La implantación del Máster en Formación del Profesorado de Educación Secundaria y Bachillerato, Formación Profesional y Enseñanza de Idiomas (MFPS) está suponiendo la participación de profesorado de diferentes áreas de conocimiento procedentes de distintas facultades. Desde el punto de vista de las didáctica de la química es una gran oportunidad para acercar los resultados de la investigación a otros ámbitos disciplinares de la química y posibilitar su puesta en práctica. Con esta intención, en la UCM, se ha llevado a cabo un proyecto audiovisual, sobre una propuesta didáctica para el equilibrio químico, como estrategia didáctica para la formación inicial de futuros profesores de secundaria de Física y Química

Two and three-dimensional oscillons in nonlinear Faraday resonance

We study 2D and 3D localised oscillating patterns in a simple model system exhibiting nonlinear Faraday resonance. The corresponding amplitude equation is shown to have exact soliton solutions which are found to be always unstable in 3D. On the contrary, the 2D solitons are shown to be stable in a certain parameter range; hence the damping and parametric driving are capable of suppressing the nonlinear blowup and dispersive decay of solitons in two dimensions. The negative feedback loop occurs via the enslaving of the soliton's phase, coupled to the driver, to its amplitude and width.Comment: 4 pages; 1 figur

Second-harmonic generation for dispersive elastic waves in a discrete granular chain

The propagation of nonlinear compressional waves in a one-dimensional granular chain driven at one end by a harmonic excitation is studied. The chain is described by a Fermi-Pasta-Ulam (FPU) lattice model with quadratic nonlinearity (alpha-FPU model), valid for strong initial compression of the chain by an external static force. A successive approximations method is used to obtain the analytical expressions for the amplitudes of the static displacement field and of the fundamental and second harmonics propagating through the lattice. Both propagating and evanescent second harmonics are shown to influence the nonlinear propagation characteristics of the fundamental frequency. The propagating regime is characterized by a periodic energy transfer between first and second harmonics, resulting from dispersion, which disappears when the second harmonic becomes evanescent.The work was financially supported by the MICINN of the Spanish Government, under Grant No. FIS2011-29734-C02-02 and by ANR Project Stabingram No. ANR-2010-BLAN-0927-03. V. S.-M. and I. P.-A. acknowledge financial support from Generalitat Valenciana, the Spanish Ministry of Science and Innovation, and Universitat Politecnica de Valencia. V. R.-G. is grateful for the support of "Programa de Contratos Post-Doctorales conMovilidad UPV del Campus de Eexcelencia Internacional (CEI-01-11)" and of Grant No. BEST2012 of the Generalitat Valenciana.Sánchez Morcillo, VJ.; Pérez Arjona, I.; Romero García, V.; Tournat, V.; Gusev, VE. (2013). Second-harmonic generation for dispersive elastic waves in a discrete granular chain. 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Inorganic arsenic causes apoptosis cell death and immunotoxicity on European sea bass (Dicentrarchus labrax)

Inorganic arsenic (As) is one of the most toxic pollutants in the water. We have studied their effects on the marine teleost European sea bass (Dicentrarchus labrax) at 2 and 10 days of 5 μMofAs2O3 (sub-lethal doses) waterborne exposure. Arsenic accumulates in liver and gill tissues. The expression profile of five genes (bax, blc2, casp3, casp8 and casp9) involved in apoptosis cell death confirmed apoptotic effects in liver, slight changes in gill and no effects in skin according with the histopathology findings. Total IgM level and peroxidase activities were increased at 2 and 10 days, respectively. The bactericidal activity was decreased at 2 days after As exposure. A general decrease of cellular immune activities with significant differences in the case of respiratory burst activity was observed after 2 and 10 days of exposure. This work describes for the first time the effects of As exposure on European sea bass.Versión del editor2,35