Effect of Reprocessing and Excipient Characteristics on Ibuprofen Tablet Properties

Purpose: To determine excipient and ibuprofen:excipient mixture sensitivity to reprocessing produced by either direct compression or wet granulation.Methods: The effect of excipient type, technology and reprocessing on flow, compressibility and compactibility was assessed using and 8x2x2 factorial design. Design Expert® v.8.01 software was employed for data analysis. Pure excipients were processed by direct compression, while the ibuprofen:excipient mixtures were processed by wet granulation. Once compacts were produced, they were milled and reprocessed using the same technologies, respectively. Excipient properties such as particle size, porosity and densities were also evaluated.Results: For most excipients, reprocessing caused a 20 – 50 % decrease in particle size and 5 – 80 % reduction in porosity, but increased compactibility (10 – 50 %). Flow decreased (30 – 50 %) only for highly densified excipients such as calcium carbonate and calcium diphosphate.Conclusion: Microcrystalline cellulose and sorbitol are the excipients with the best tableting properties when reprocessing is conducted via wet granulation and direct compression platforms, respectively.Keywords: Reprocessing, Excipient, Microcrystalline Cellulose, Sorbitol Direct Compression, Wet Granulation, Ibuprofe

El estudio arqueométrico de la producciones cerámicas

El estudio de la pasta de las cerámicas mediante lámina delgada, difracción de rayos X y su análisis quimico permite profundizar en el conocimiento sobre el origen de las mismas y en su tecnología de elaboración, asi como determinar las temperaturas minimas o maximas de cocción alcanzadas. De igual modo permite poner de manifiesto las modificaciones posteriores sufridas por el uso continuado de las mismas y por procesos tardíos debidos al soterramiento de las piezas. Los resultados obtenidos cotejados con la informacion arqueológica, la contextualización de los yacimientos y el entorno cultural de cada época permite constatar en algunos casos pautas comerciales o de intercambi

Spin Signature of Nonlocal Correlation Binding in Metal-Organic Frameworks

We develop a proper nonempirical spin-density formalism for the van der Waals density functional (vdW-DF) method. We show that this generalization, termed svdW-DF, is firmly rooted in the single-particle nature of exchange and we test it on a range of spin systems. We investigate in detail the role of spin in the nonlocal correlation driven adsorption of H-2 and CO2 in the linear magnets Mn-MOF74, Fe-MOF74, Co-MOF74, and Ni-MOF74. In all cases, we find that spin plays a significant role during the adsorption process despite the general weakness of the molecular-magnetic responses. The case of CO2 adsorption in Ni-MOF74 is particularly interesting, as the inclusion of spin effects results in an increased attraction, opposite to what the diamagnetic nature of CO2 would suggest. We explain this counterintuitive result, tracking the behavior to a coincidental hybridization of the O p states with the Ni d states in the down-spin channel. More generally, by providing insight on nonlocal correlation in concert with spin effects, our nonempirical svdW-DF method opens the door for a deeper understanding of weak nonlocal magnetic interactions

Influence of the diatomite specie on the peak and residual shear strength of the fine-grained soil

Diatomite is a powdering mineral mainly composed of diatom microfossils present in marine and lacustrine soils, which influences their physical and mechanical properties. Although many articles have been found in the literature concerning the influence of diatomite in the overall behavior of natural soils, few research efforts have been carried out to evaluate the influence of the diatom microfossil species on their shear resistance. Therefore, in this research, the influence of the diatomite species and the content in the peak and the residual shear strength of diatomite-fine grained soil mixtures was analyzed using the annular shear strength test. Scanning electron microscopy (SEM) and Atterberg limits were also carried out as additional tests to explain the interlocking effect between the microfossils and the soil. Overall, both diatomite species increased both peak and residual shear strength of the soil similar to dense sands. Nevertheless, the Mexican species reveal higher friction angle values compared with Colombian species

Imantodes inornatus (Boulenger, 1886) (Squamata: Dipsadidae): expansión del rango de la distribución conocida y primeros registros del valle del río Magdalena, Colombia

The first report of the Speckled Blunt-headed Tree Snake (Imantodes inornatus) is presented for the Magdalena River valley, from the departments of Antioquia, Bolívar, Boyacá and Caldas in Colombia. Since these records correspond to the biogeographic Magdalena province, the known range for the species is expanded. In Colombia, this is a trans-Andean species found from the Pacific rainforests of the Chocó region, through the northern portion of the Western and Central Andean ranges, to the middle Magdalena River valley.Se registra por primera vez la serpiente de árbol cabeza moteada (Imantodes inornatus) en el valle del río Magdalena en los departamentos de Antioquia, Bolívar, Boyacá y Caldas, en Colombia. Estos registros corresponden a la provincia biogeográfica del Magdalena, lo que aumenta el área de distribución conocida. En Colombia, esta especie es un elemento transandino que cruza las selvas tropicales del Pacífico de la región chocoana, a través de la porción septentrional de las cordilleras Occidental y Central hasta el valle medio del río Magdalena

MACUIRA GNEISS: TECTONIC EVOLUTION OF THE PALEOZOIC METAMORPHIC ROCKS, ALTA GUAJIRA – COLOMBIA

El Neis de Macuira es una unidad metamórfica Paleozoica que aflora en las serranías de Simarua, Jarara y Macuira, Alta Guajira. Se trata de un conjunto litológico que sufrió metamorfismo bajo condiciones de P-T en la facies anfibolita y consta de neises anfibólicos y cuarzo-feldespáticos, anfibolitas, esquistos, pegmatitas, rocas calco-silicáticas y mármoles, con evidencias de migmatización en neises y anfibolitas. En la unidad se observan cinco foliaciones (S1-5) y tres eventos de plegamiento (F1-3) interpretados como producto de dos eventos metamórficos desarrollados en un gradiente metamórfico barroviano progresivo con relaciones P-T intermedias, y relacionados con tectónica de colisión continental. La unidad es importante en el entendimiento de la evolución tectónica de la Alta Guajira y el Caribe debido a que registra diferentes fases deformativas pre-, sin- y post-migmatíticas que podrían relacionarse con diferentes episodios tectónicos: el primero relacionado con la colisión de Laurasia y Gondwana (Orogenia Alleghaniana - Paleozoico Tardío) y el segundo relacionado con la evolución de la Placa Caribe (Orogenia Andina - Meso a Cenozoico). Palabras clave: Migmatitas, Deformación, Orogenia Alleghaniana, Alta Guajira, ColombiaThe Macuira Gneiss is a Paleozoic metamorphic unit that outcrops in the Simarua, Jarara and Macuira ranges, Alta Guajira. It is composed by a lithologies metamorphosed under amphibolite facies P-T conditions and consist of amphibolitic and quartz feldspathic gneisses, amphibolites, schists, pegmatites, calc-silicated rocks and marbles, with migmatization evidences in gneisses and amphibolites. Five foliations (S1-5) and three folding events (F1-3) were identified and interpreted as product of two metamorphic events, developed in a progressive barrovian metamorphic gradient of intermediate pressure with intermediate P-T ratio, interpreted as product of continental collision tectonics. This unit is important in understanding of the tectonic evolution of the Alta Guajira and Caribbean because it records different deformational phases pre-, syn- and post-migmatitic, that could be related with different tectonic episodes: the first associated with the collision between Laurasia and Gondwana (Alleghanian Orogeny - Late Paleozoic), and the second related with the Caribbean Plate evolution (Andean Orogeny - Meso-Cenozoic). Keywords: Migmatites, Deformation, Alleghanian orogeny, Alta Guajira, Colombia. &nbsp

MACUIRA GNEISS: TECTONIC EVOLUTION OF THE PALEOZOIC METAMORPHIC ROCKS, ALTA GUAJIRA – COLOMBIA

El Neis de Macuira es una unidad metamórfica Paleozoica que aflora en las serranías de Simarua, Jarara y Macuira, Alta Guajira. Se trata de un conjunto litológico que sufrió metamorfismo bajo condiciones de P-T en la facies anfibolita y consta de neises anfibólicos y cuarzo-feldespáticos, anfibolitas, esquistos, pegmatitas, rocas calco-silicáticas y mármoles, con evidencias de migmatización en neises y anfibolitas. En la unidad se observan cinco foliaciones (S1-5) y tres eventos de plegamiento (F1-3) interpretados como producto de dos eventos metamórficos desarrollados en un gradiente metamórfico barroviano progresivo con relaciones P-T intermedias, y relacionados con tectónica de colisión continental. La unidad es importante en el entendimiento de la evolución tectónica de la Alta Guajira y el Caribe debido a que registra diferentes fases deformativas pre-, sin- y post-migmatíticas que podrían relacionarse con diferentes episodios tectónicos: el primero relacionado con la colisión de Laurasia y Gondwana (Orogenia Alleghaniana - Paleozoico Tardío) y el segundo relacionado con la evolución de la Placa Caribe (Orogenia Andina - Meso a Cenozoico). Palabras clave: Migmatitas, Deformación, Orogenia Alleghaniana, Alta Guajira, ColombiaThe Macuira Gneiss is a Paleozoic metamorphic unit that outcrops in the Simarua, Jarara and Macuira ranges, Alta Guajira. It is composed by a lithologies metamorphosed under amphibolite facies P-T conditions and consist of amphibolitic and quartz feldspathic gneisses, amphibolites, schists, pegmatites, calc-silicated rocks and marbles, with migmatization evidences in gneisses and amphibolites. Five foliations (S1-5) and three folding events (F1-3) were identified and interpreted as product of two metamorphic events, developed in a progressive barrovian metamorphic gradient of intermediate pressure with intermediate P-T ratio, interpreted as product of continental collision tectonics. This unit is important in understanding of the tectonic evolution of the Alta Guajira and Caribbean because it records different deformational phases pre-, syn- and post-migmatitic, that could be related with different tectonic episodes: the first associated with the collision between Laurasia and Gondwana (Alleghanian Orogeny - Late Paleozoic), and the second related with the Caribbean Plate evolution (Andean Orogeny - Meso-Cenozoic). Keywords: Migmatites, Deformation, Alleghanian orogeny, Alta Guajira, Colombia. &nbsp