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Design and development of a stimuli-responsive oral tablet system for the treatment of ulcerative colitisBawa, Priya 26 October 2011 (has links)
M.Pharm., Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 2011. / Ulcerative colitis (UC), notorious for its unpredictable attacks of inflammation of the large intestine, is
estimated to affect as many as 1.4 million people in the USA and 2.2 million people in Europe with
15000-30000 new cases being diagnosed annually worldwide. The chronic inflammatory process is
limited to various regions of the colonic mucosa and is postulated to occur due to a dysregulated
mucosal response in the intestinal wall, facilitated by defects in the protective barrier function of the
intestinal epithelium and mucosal immune system. Due to the range and extent of disease
manifestations the goals of UC therapy are broad and non-specific. The focus of therapy is thus
primarily placed on the treatment of active disease by ameliorating the signs and symptoms
characteristic of the disease state with concurrent adjunctive and anti-inflammatory therapy. Thus,
ideally a delivery system should facilitate a reduction in the pill burden, daily dosing requirements and
allow for concurrent adjunctive and anti-inflammatory therapy with a single delivery system
administration. Therefore, essentially the purpose of this work was to develop a novel stimuliresponsive
oral tablet system (SROT) that provided targeted drug delivery of 5-ASA to the colon and
loperamide HCl to the small intestine with a single delivery system. For this purpose, the employment
of polymers that are termed ‘stimuli-responsive’ or ‘smart’ were established to be the most attractive
approach for ‘activating’ drug release at the desired site in response to the pre-determined reliable
stimulus. Thus, advantage is taken of the over 400 distinct species of anaerobic bacteria and their
corresponding enzymatic activities in the colon.
Investigations performed according to a Box-Behnken experimental design exposed an optimum
enzyme-responsive colon-targeted tablet that effectively inhibited premature 5-ASA release in
conditions simulating the upper gastrointestinal tract, whilst enabling an immediate initiation of drug
release on exposure to colonic enzymes. The enzyme-responsiveness of the tablet was a direct result
of the employment of only naturally-derived polysaccharides that were susceptible to colonic
degradation. Furthermore, and more importantly, the prevention of premature drug release was
achieved by the enzyme-responsive hydrophobic coating consisting of pectin and an aqueous
ethycellulose dispersion that was applied to tablets until a ±10% total weight gain was achieved. In
addition the in situ crosslinking between pectin and BaCl2 in the tablet matrix as well as the
crosslinked 5-ASA-loaded granules resulted in a zero-order drug release throughout the 18 hour
period in the simulated colonic environment containing enzymes.
The development of the outer pepsin-responsive small intestinally-targeted coating was also
conducted according to the Box-Behnken experimental design. Extensive investigations revealed an
optimized pepsin-responsive coating after conducting the relevant studies on the 15 statisticallyderived
formulations. Essentially, the tablets coated with the 40%w/v gelatine solutions resulted in the
greatest increase in weight and shell thickness of the formulations however these were the least
responsive to pepsin. The optimum pepsin-responsiveness was achieved from a gelatine coating of
14.379%w/v which was crosslinked for 6 hours in a glutaraldehyde-lactose dry mixture. Furthermore,
the novel crosslinking method ensured that no entrapped loperamide HCl was prematurely lost during
the crosslinking process. In addition, the optimum formulation also achieved 100% drug release in the
small intestine-at its site of therapeutic action.
In vivo investigations of the SROT in the large white pig model explicated the colon-targeting ability of
the 5-ASA-loaded tablet as well as the benefits of the SROT compared to the conventional
commercially available system, Asacol® (Aventis Pharma (Pty) Ltd.,Midrand, Johannesburg, South
Africa). The success of the loperamide-loaded coating was evident from the minimal presence of
loperamide HCl in plasma in the first 2 hours post-dosing compared to its commercially available
counterpart Imodium® (Janssen Pharmaceutica (Pty) Ltd., Woodmead, Johannesburg, South Africa).
Investigations into an alternate colon-targeted drug delivery system revealed 3 novel composite
polyacrylamide-polysaccharide hydrolyzed electrolytic matrices consisting of either pectin, chitosan or
a combination of both, complexed with hydrolyzed polyacrylamide. Each matrix presented with varying
surface area and porositometric properties which influenced their drug release behaviour. These
formulations hold potential for numerous controlled drug delivery applications and are not exclusively
limited to colon-targeting.
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nonehan, wen 21 July 2008 (has links)
none
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Modelling and optimisation of pharmaceutical formulations and processesZolotariov, Eyal January 2001 (has links)
No description available.
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The effect of wet granulation on the physico-mechanical characteristics of microcrystalline celluloseChatrath, Meena January 1992 (has links)
No description available.
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Získávání dat z tabletu / Tablet data acquisitionZvak, Martin January 2010 (has links)
Reliable authorization and authentication is now becoming necessary for many everyday activities such as boarding an aircraft, doing financial transactions etc. This work deals with the possibility of proposing an appropriate method of acquisition, processing and evaluation of data from the tablet itself, focusing on the possibility of obtaining data from the graphics tablet used in conjunction with a personal computer, for the purpose of verifying identity. It contains an overview of biometrics, as independent developing science over the last decades of the 20th century to the present, a summary of the development of a graphics tablet, the current situation, a brief overview of the most popular technologies used in their construction and distribution. Furthermore, it focuses on the design and implementation of appropriate procedures to obtain data provided by the Trust tablet TB - 7300, using available software development kit for the Microsoft Tablet PC, and a comparison of WinForms and WPF model (.NET Framework), with the declaration of suitability for the use of the second one. Last but not least, according to the response from the available set of users, this work focuses on the design of appropriate types of input data, test patterns, method and application for collecting and processing data from the graphic tablet, as well as their use for the verification of the identity of the individual. Ultimately, it is possible to discuss the accuracy of the method on a set of users, its suitability for use and shortcomings. Based on the analysis of the issue, the proposed method can be declared as under-optimal - it is safe, but inaccurate with low stability and repeatability. It is also important to accent that this is just the initial proposal, the use of applications in everyday life is for current phase impossible and the transition from laboratory conditions would require further development and improvement of the process.
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The new faces of interactivity : analysis & implementation of a mobile application : NewsieOliveira, Cristina Maria Lopes dos Santos January 2010 (has links)
Tese de mestrado integrado. Engenharia em Multimédia. Faculdade de Engenharia. Universidade do Porto. 2010
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The Usability and Learnability of Pen/Tablet Mode InferencingNegulescu, Matei January 2012 (has links)
The inferred mode protocol uses contextual reasoning and local mediators to eliminate
the need to access specic modes to perform draw, select, move and delete operations in a
sketch interface. This thesis describe an observational experiment to understand the learn-
ability, user preference and frequency of use of mode inferencing in a sketch appli- cation.
Novel methodology is presented to study both quantitative and long term qualitative facets
of mode inferencing. The experiment demonstrated that participants instructed in the in-
terface features enjoyed fluid transitions between modes. As well, interaction techniques
were not self-revealing: Participants who were not instructed in interaction techniques took
longer to learn about inferred mode features and were more negative about the interaction
techniques. Over multiple sketching sessions, as users develop expertise with the system,
they combine inferred mode techniques to speed interaction, and frequently make use of
scratch space on the display to retrain themselves and to tune their behaviors. Lastly, post-
task interviews outline impediments to discoverability and how performance is affected by
negative perceptions around computational intelligence. The results of this work inform
the design of sketch interface techniques that incorporate noncommand features.
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Surfplattan : Intentioner och implementering i förskolanHöglund, Jennie January 2014 (has links)
The intention is to focus on the implementation of the tablet in preschools and how the intentions around the introduction of the tablet take shape in different preschools. The method is semi structured interviews where the respondents consist of 3 preschool directors and 6 teachers where the preschool directors work. This is a relevant subject to illustrate, as the tablet has become a tool in preschool where it seems to be different opinions about how it should be used. This study aims to understand how the implementation can take form in different preschools, what kind of similarities and differences we can see with the intentions of the tablet and if there is need of clarification on the workings of the tablets in preschools. The results show that the intentions around the introduction of the tablet in preschool look different in the preschools, and the implementation of this new technology starts in a small scale with help of photographing and videotaping. In addition to this, there is no specific thought on how the tablets should be implemented in preschool. / Avsikten är att fokusera på implementeringen utav surfplattan i förskoleverksamheten och hur intentionen kring införandet utav surfplattan ser ut på olika förskolor. Metoden är semistrukturerade intervjuer där respondenterna består utav 3 förskolechefer och 6 pedagoger där respektive förskolechef verkar. Detta är ett relevant ämne att belysa, då surfplattan har blivit ett verktyg i förskolan som det verkar finnas olika uppfattningar om vad och hur den skall användas till. Därigenom syftar denna undersökning till att se hur implementeringen utav surfplattan kan se ut på olika förskolor, vad för likheter och olikheter kan vi se med intentionen utav surfplattan och om finns det behov av tydliggörande utav arbetet kring surfplattorna i verksamheten. Resultatet visar på att intentionerna kring införandet utav surfplattor i verksamheten ser olika ut på de representerade förskolorna, samt att implementeringen utav denna nya teknik påbörjas i liten skala med hjälp utav fotografering och filmning. Utöver detta har inga specifika tankar funnits kring hur surfplattorna ska implementeras i verksamheten.
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The Usability and Learnability of Pen/Tablet Mode InferencingNegulescu, Matei January 2012 (has links)
The inferred mode protocol uses contextual reasoning and local mediators to eliminate
the need to access specic modes to perform draw, select, move and delete operations in a
sketch interface. This thesis describe an observational experiment to understand the learn-
ability, user preference and frequency of use of mode inferencing in a sketch appli- cation.
Novel methodology is presented to study both quantitative and long term qualitative facets
of mode inferencing. The experiment demonstrated that participants instructed in the in-
terface features enjoyed fluid transitions between modes. As well, interaction techniques
were not self-revealing: Participants who were not instructed in interaction techniques took
longer to learn about inferred mode features and were more negative about the interaction
techniques. Over multiple sketching sessions, as users develop expertise with the system,
they combine inferred mode techniques to speed interaction, and frequently make use of
scratch space on the display to retrain themselves and to tune their behaviors. Lastly, post-
task interviews outline impediments to discoverability and how performance is affected by
negative perceptions around computational intelligence. The results of this work inform
the design of sketch interface techniques that incorporate noncommand features.
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Tablet application GUI usability checklist : Creation of a user interface usability checklist for tablet applications / GUI-användbarhets-checklista för applikationer på surfplattor : Användbarhetschecklista för utvärdering av surfplatts-applikationsgränsnittXu, Henrik January 2013 (has links)
Since the beginning of the 21st century, the world has seen a changing trend in computing power thanks to advancements in technology. One peculiar platform in the field of usability is the tablet. Due to its recent introduction, it has had a relatively short life span with few established methodologies. The tablet is gaining market share at a tremendous speed and thus there has been a big demand of the appropriate evaluation methods. This comprehensive study intention is to; through a literature survey and transformation of collected material identify what usability requisites there are when developing a user interface for a tablet application. Existing user interface guidelines from various companies involving the development of tablet software are examined and paired up with usability principles in the creation of the usability checklist. The usability checklist practical effectiveness is tested on various tablet applications and the results are compared to the results of a usability user test valuation. The majority of the usability problems found by the user test evaluation are codiscovered, in addition, there were a greater number of undiscovered usability problems that was identified with the checklist evaluation.
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