1,720,958 research outputs found
Development of flexible and dispersible oral formulations containing praziquantel for potential schistosomiasis treatment of pre-school age children
No full textPraziquantel (PZQ), an anthelmintic drug used in developing countries for the treatment of schistosome infections, was processed using the fluid bed wet granulation technology to prepare fast dispersible granules, as an appropriate and flexible dosage form for pre-school-aged children. Granulation experiments were performed incorporating PZQ either in the powder mixture, according to the traditional way, or in the liquid phase containing wetting agents. In the powder mixture several excipients were tested: Flowlac 100 as filler, Galeniq 721 (isomalt) and Neosorb P 100 T (D-sorbitol) as sweeteners and PVP K30 as binder; while in the liquid phase Lutrol F68, Cremophor RH 40 or Tween 80 as surfactants were investigated. Different formulations loaded with 10% w/w (batches 1-8) and 20% w/w of PZQ (batches 9-13) were produced The majority of granules displayed good flow properties and uniform drug content. X-ray powder diffraction showed that PZQ remained in its original crystalline state, while differential scanning calorimetry and Fourier transform-infrared analysis evidenced the formation of chemical interactions among the ingredients. The solubilisation test performed in non-sink condition to reproduce the actual condition in which a child of 4 years takes the medicine revealed that granules quickly formed a very fine suspension in water (dV90 = 39.9 μm). Although after the granulation process the solubility of raw PZQ was not increased, adding the aqueous suspension to 500 ml of buffer solution of pH 1.5, simulating the fasted state of a child, 50% of the drug was dissolved after 30 min. After granule manipulation with milk and fruit juices, no PZQ degradation was observed during time. Finally, the selected granule formulation provided evidence to be stable even at hot and very humid climate (30°C/75% RH), at least for the examined time
Development of Innovative Formulations for Paediatric Use
No full textChildren around the world are routinely being treated with medicines that have not been designed and developed for this specific patient population, putting them at risk of inaccurate dosing and side effects.
In the view of these considerations, the PhD research project was addressed to the use of specific formulation strategies for the development of innovative paediatric dosage forms.
The research has been structured in three case studies, concerning different oral formulations: mucoadhesive buccal films, dispersible granules and complex suspensions.
The first part of the research investigated the use of polymeric films for systemic absorption of ondansetron hydrochloride through the buccal mucosa. Several mixtures of hydrophilic polymers were evaluated to optimize the hydration ability of such films, the residence time at the site of application and the drug permeation profile.
The second approach was focused on the development of fast dispersible granules for oral administration of praziquantel. Granules represent a flexible dosage form for preschool-aged children that can be given as dispersion in beverages or administered with food, improving the palatability of the formulations and the adherence to therapy.
The last part of the work was carried out at the University of Birmingham and faced one of the central challenge associated with paediatric treatment: the taste masking of molecules characterized by bitter taste. To achieve this purpose, polyelectrolyte complexes, composed of whey protein and pectin, and able to encapsulate active substances were developed. Caffeine was selected as model drug for its particularly bitter taste.
Finally, the results presented in this thesis demonstrated that specific formulation strategies can be used to overcome the predominant issues related to paediatric administration of medicines, in order to guarantee the complete adherence of children to the therapy and thus the success of the treatment
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
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
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
An explorative analysis of process and formulation variables affecting comilling in a vibrational mill: The case of praziquantel
Full text linkPraziquantel, a BCS II class anthelmintic drug used for the treatment of schistosome infections, was coground in a vibrational mill with different polymers (linear and crosslinked povidone, copovidone and sodium starch glycolate). An explorative analysis of formulation variables (drug-polymer wt ratio and polymer type) and process parameters (type of grinding media, grinding time and frequency) was carried out with the help of an experimental screening design. The influence of the above mentioned factors on three PZQ characteristics (residual crystallinity, water solubility enhancement and drug recovery) was studied. The variation of carrier amount proved to be by far the most important variable affecting all the experimental responses. A lower impact and, in some cases, rather null effect, had the variation of the process variables. All coground systems were characterized by a high amorphous degree and a solubility significantly higher than the API. A very promising product was obtained by processing at 20 Hz for 4 h, using 3 spheres of 15 mm as grinding media, i.e. a coground having a 50% API content, showing a 4.6-fold greater solubility at 20 C than pure praziquantel. This product maintained the same antischistosomal activity of pure API and was both physically and chemically stable for at least 6 months.
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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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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