1,720,987 research outputs found
Hydrogel blends with adjustable properties as patches for transdermal delivery.
No full textThe effect of different preparation parameters were analyzed with respect to the rheological and pharmaceutical characteristics of hydrogel blend patches, as transdermal delivery formulation. Mixtures of pectin and gelatin were employed for the production of patches, with adjustable properties, following a two-step gelation procedure. The first gelation, a thermal one, is trigged by the presence of gelatin, whereas, the second gelation, an ionic one, is due to the formation of the typical egg box structure of pectin. In particular, the patch structural properties were assessed by oscillation stress sweep measurements which provided information concerning their viscolelastic properties. In addition, different modalities for drug loading were analyzed with respect to drug homogeneous distribution; testosterone was employed as model drug for transdermal administration. Finally, the performances of the produced transdermal patches were studied, in term of reproducibility and reliability, by determination of in vitro drug release profiles
Rheological and functional characterization of new antiinflammatory delivery systems designed for buccal administration
No full textThe aim of the present paper was to investigate the influence of different formulation parameters on the rheological and functional properties of emulgels (gelified emulsions), intended for the buccal administration of the antiinflammatory drug flurbiprofen. The influence of formulation parameters, such as (a) the amount of gelling polymeric emulsifier (Pemulen® 1621 TR-1) used, (b) the oil to water ratio present in the O/W emulgel and finally (c) the pH of the formulation, was studied by a experimental design (DoE) approach. Formulations were analyzed in term of size and morphology of the internal semi-solid oil droplets as well as in term of rheological properties in the presence or in the absence of flurbiprofen by "shear stress vs. shear rate tests" and "frequency sweep tests". Emulgels were also characterized in vitro both by bioadhesion tests and release studies. In particular release studies demonstrated that flurbiprofen is released by the emulgels in a controlled manner, the drug release efficacy within the first 100 min was comprised between 50 and 80% of the total amount of the drug. Finally, in vivo tests on healthy volunteers have demonstrated that emulgels were able to remain on buccal mucosa for an average period of 1 h, moreover emulgels did not have bad taste and volunteers referred that were agreeable and pleasant. © 2007 Elsevier B.V. All rights reserved
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
Safety of nanoclay/spring water hydrogels: Assessment and mobility of hazardous elements
No full textThe presence of impurities in medicinal products have to be controlled within safety limits from a pharmaceutical quality perspective. This matter is of special significance for those countries and regions where the directives, guidelines, or legislations, which prescribe the rules for the application of some products is quite selective or incomplete. Clay-based hydrogels are quite an example of this matter since they are topically administered, but, in some regions, they are not subjected to well-defined legal regulations. Since hydrogels establish an intimate contact with the skin, hazardous elements present in the ingredients could potentially be bioavailable and compromise their safety. The elemental composition and mobility of elements present in two hydrogels have been assessed. Sepiolite, palygorskite, and natural spring water were used as ingredients. The release of a particular element mainly depends on its position in the structure of the hydrogels, not only on its concentration in each ingredient. As a general trend, elements’ mobility reduced with time. Among the most dangerous elements, whose presence in cosmetics is strictly forbidden by European legal regulations, As and Cd were mobile, although in very low amounts (0.1 and 0.2 μg/100g of hydrogel, respectively). That is, assuming 100% bioavailability, the studied hydrogels would be completely safe at normal doses. Although there is no sufficient evidence to confirm that their presence is detrimental to hydrogels safety, legally speaking, their mobility could hinder the authorization of these hydrogels as medicines or cosmetics. In conclusion, the present study demonstrates that hydrogels prepared with sepiolite, palygorskite, and Alicún spring water could be topically applied without major intoxication risks
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
Novel mucoadhesive buccal formulation containing metronidazole for the treatment of periodontal disease
No full textMucoadhesive tablets using different mixture of cellulose and polyacrylic derivatives were prepared in order to obtain new formulations containing metronidazole for periodontal disease treatment. All tablets were characterized by swelling studies, ex vivo and in vivo mucoadhesive time, ex vivo mucoadhesion force, in vitro and in vivo release. The best mucoadhesive performance and the best in vitro drug release profile were achieved by using hydroxyethyl cellulose (HEC) and carbomer 940 2:2 ratio. The chosen tablet, containing 20 mg of metronidazole, performed 12 h drug sustained release with buccal concentrations always higher than its MIC
Pleuropolmonite fibrinosa e rinite atrofica del suino: proprietà immunogena di un vaccino spento
No full textStudies on annelated 1,4-benzothiazines and 1,5-benzothiazepines. VIII-Synthesis and inhibition of benzodiazepine receptor binding of some derivatives of triazino[3,4-c]-1,4-benzothiazine and triazino[3,4-d]-1,5-benzothiazepine, two new heterocyclic ring systems.
No full textSeveral series of triazino[3,4-c]-1,4-benzothiazines and triazino[3,4-d]-1,5-benzothiazepines were synthesized. Tentative syntheses performed to obtain 5H-as-triazino[3,4-c]-1,4-benzothiazin-1,2-diones and 5,6-dihydro-as-triazino[3,4-d]-1,5-benzothiazepin-1,2-diones gave rise to s-triazolo derivatives. Only in one case was the reaction successful, affording the 3,5-dihydro-as-triazino[3,4-c]-1,4-benzothiazin-1,2-dione 9a. All the final compounds were tested for their ability to displace [3H]flunitrazepam from bovine brain membranes
- …
