1,720,976 research outputs found
Bioavailability of metoclopramide from a new chewing gum device
No full textMetoclopramide is widely used in the treatment of nausea. The development of metoclopramide as medicated chewing gum has potential advantages in terms of patient compliance, fast onset of effect and improved bioavailability. In this study, bioavailability of metoclopramide from a new chewing gum device, 3TabGum, was evaluated in healthy volunteers. Medicated chewing gum was well tolerated in all subjects. Compared with immediate release tablets, AUC following administration of chewing gum was higher (224.9 vs. 166.5 ng h/mL), while t max was smaller (1.38 vs. 1.88 h), suggesting improved bioavailability and rapid onset of drug absorption. However, absorption rate was lower, as evidenced by lower C max (17.2 vs. 20.8 ng/mL). Terminal half-life was prolonged (11.58 vs. 5.35 h), implying that initial fast release of metoclopramide is followed by much slower release of the remaining smaller portion of the drug. These results indicate that chewing gum is a promising alternative to current metoclopramide formulation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
HELICOIDAL WAXY MATRICES AS SUSTAINED DRUG DELIVERY SYSTEMS OBTAINED BY MELT EXTRUSION
Full text linkPreparation end in vitro/in vivo characterisation of melt pelletised paracetamol/stearic acid sustained release delivery system
No full textThe potential of a sustained release formulation for paracetamol produced by melt pelletisation was investigated. After the production of the pellets, based on the combination of stearic acid as a melting binder and anhydrous lactose as a filler, the 3000-2000 μm size fraction was selected in the light of the promising in vitro dissolution results for further characterisations, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area and true density determination. Hence the release mechanism was analysed with the help of an appropriate mathematical model. The mathematical model was built on the hypotheses that drug diffusion and solid drug dissolution in the release environment are the key phenomena affecting drug release kinetics. Bioavailability of the developed formulation was evaluated in an in vivo study in eight subjects
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
EFFECT OF COMPOSITION ON THE RELEASE FROM MELT EXTRUDED LAMINAR SYSTEMS BY APPLICATION OF MIXTURE EXPERIMENTAL DESIGN
No full textEFFECT OF COMPOSITION ON THE RELEASE FROM MELT EXTRUDED LAMINAR SYSTEMS BY APPLICATION OF MIXTURE
EXPERIMENTAL DESIG
Preparation in high-shear mixer of sustained-release pellets by melt pelletisation
No full textThe preparation of sustained-release pellets by melt pelletisation was investigated in a 10-l high shear mixer and
ternary mixtures containing stearic acid as a melting binder, anhydrous lactose as a filler and theophylline as a model
drug. A translated Doehlert matrix was applied for the optimisation of process variables and quality control of pellets
characteristics. After determination of size distribution, the pellets were characterised with scanning electron
microscopy, X-ray photoelectron spectroscopy and porosimetric analysis. Finally, the in vitro release from every
single size fraction was evaluated and the release mechanism was analysed. Since the drug release rate decreased when
enhancing the pellet size fraction, the 2000-mm fraction, exhibiting a substantially zero-order release, was selected for
further in vivo biovailability studies. These data demonstrated that pellets based on the combination of stearic acid
and lactose can be used to formulate sustained release pellets for theophylline. © 2000 Elsevier Science B.V. All rights
reserved
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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