849 resultados para Excipients for tablets
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Despite recent success, rapidly disintegrating lyophilized tablets still face problems of low mechanical strength and higher disintegration times resulting in poor patient compliance. The aim of the current work was to carry out a systematic study to understand the factors controlling mechanical properties of these formulations. The work investigated the influence of two bloom strengths of gelatin: low (60 bloom) and high (225 bloom) at different stock solution concentrations (2, 5, 7.5, and 10 %w/w). This was followed by investigation of addition of five saccharides (xylitol, glucose, trehalose, maltotriose and mannitol) at varied concentration range (10-80 %w/w) to decipher their influence on disintegration time, mechanical and thermal properties of the formulation. The results indicated that the disintegration time of the tablets dramatically decreased by decreasing the concentration and bloom strength of gelatin in the stock solution. However the mechanical properties of the tablets were mainly influenced by the concentration of gelatin rather than the bloom strength. The addition of saccharides resulted in enhancement of tablet properties and was concentration dependent. All the saccharides improved the fractubility of the tablets significantly at high concentration (equal or higher than 40% w/w). However, only high concentration (equal or higher than 40% w/w) of trehalose, maltotriose and mannitol significantly enhanced the hardness. Additionally, mannitol crytallised during freeze drying and consequently produced elegant tablets, whilst the other saccarides exhibited lyoprotectant activity as they were able to retain amorphous status. Based on the above findings, an optimized formulation was also successfully developed and characterized to deliver 100 microg dose of Clonidine HCl.
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A novel method for tablet coating was studied where a thin polymer film was cast (pre-formed film), dried and applied as a coating hence eliminating the need for using any solvent during the actual coating process. A pre-formed film is initially heating to a temperature where it becomes flexible, a vacuum is applied and the film is then pulled around the tablet. The proposed films (gelatine or cellulose-based) were characterised in terms of their dissolution, swelling, mechanical and thermal properties prior to using them in the novel coating process; selected films were then coated onto tablets containing paracetamol or ibuprofen and the effect of the film on the subsequent dissolution was evaluated. It was found that the pre-formed films could be designed to be fast dissolving and mechanically strong to withstand the stress from the coating process. Also metoclopramide was incorporated in a gelatine film-coating formulation which was then successfully coated on paracetamol-containing core. Gelatin-based films were found to be successful in the novel coating process therefore to be suitable as finished coatings for immediate release dosage forms. Orally disintegrating dosage forms have been identified as a favourable dosage form due to the following reasons: fast onset of drug release, easy to use, not painful and possible increase of amount absorbed to systemic circulation. Selected films formulated for coating studies were also successfully formulated to contain active ingredient suitable for orally disintegrating dosage form; cellulose-based naratriptan-films were studied as orally disintegrating dosage forms of where the effect of formulation on the film properties was studied. It was found that strength of the film can affect the dissolution of the film but it may be the inclusion of specific excipients in the formulation which affect the penetration of the drug through mucosa.
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This paper presents the digital imaging results of a collaborative research project working toward the generation of an on-line interactive digital image database of signs from ancient cuneiform tablets. An important aim of this project is the application of forensic analysis to the cuneiform symbols to identify scribal hands. Cuneiform tablets are amongst the earliest records of written communication, and could be considered as one of the original information technologies; an accessible, portable and robust medium for communication across distance and time. The earliest examples are up to 5,000 years old, and the writing technique remained in use for some 3,000 years. Unfortunately, only a small fraction of these tablets can be made available for display in museums and much important academic work has yet to be performed on the very large numbers of tablets to which there is necessarily restricted access. Our paper will describe the challenges encountered in the 2D image capture of a sample set of tablets held in the British Museum, explaining the motivation for attempting 3D imaging and the results of initial experiments scanning the smaller, more densely inscribed cuneiform tablets. We will also discuss the tractability of 3D digital capture, representation and manipulation, and investigate the requirements for scaleable data compression and transmission methods. Additional information can be found on the project website: www.cuneiform.net
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A simple elementary osmotic pump (EOP) system that could deliver metformin hydrochloride (MT) and glipizide (GZ) simultaneously for extended periods of time was developed in order to reduce the problems associated with multidrug therapy of type 2 non-insulin-dependent diabetes mellitus. In general, both highly and poorly water-soluble drugs are not good candidates for elementary osmotic delivery. However, MT is a highly soluble drug with a high dose (500 mg) while GZ is a water-insoluble drug with a low dose (5 mg) so it is a great challenge to pharmacists to provide satisfactory extended release of MT and GZ. In this paper sodium carbonate was used to modulate the solubility of GZ within the core and MT was not only one of the active ingredients but also the osmotic agent. The optimal EOP was found to deliver both drugs at a rate of approximately zero order for up to 10 h in pH 6.8, independent of environment media. In-vivo evaluation was performed relative to the equivalent dose of conventional MT tablet and GZ tablet by a cross-study in six Beagle dogs. The EOP had a good sustained effect in comparison with the conventional product. The prototype design of the system could be applied to other combinations of drugs used for cardiovascular diseases, diabetes, etc.
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Areas covered: The review discusses the main challenges of ODT manufacturing process and the emerging solutions featured at early drug development stages. The research specifically describes the methods reported for taste masking/assessment and solubilisation of unpalatable and poorly soluble drugs, respectively. Furthermore, this review highlights the techniques used for developing modified-release ODTs, an emerging area in the field. In addition, it also discusses the poor flowability and segregation problems of directly compressed powders. Moreover, the review describes the tests reported in the literature for ODT disintegration time assessment since a universal technique is still non-existent. Expert opinion: The approaches used to overcome the manufacturing challenges often have a bearing on the price of the end product. However, despite the technical and regulatory challenges, ODTs can offer many advantages over the conventional dosage forms if accompanied by suitable adjuvant technologies and in vitro analytical tools. © 2014 Informa UK, Ltd. Introduction: Orally disintegrating tablets (ODTs) provide several advantages over conventional tablets such as suitability for patients with swallowing difficulties and faster onset of action. The manufacture of ODTs by compression/tableting offers a practical and cost-effective strategy over the freeze drying (lyophilisation) method. Nonetheless, the FDA recommends a disintegration time of 30 s and a maximum weight of 500 mg for a tablet to be labelled as an ODT. These requirements, alongside other desirable product properties, have created a number of challenges for the formulator to overcome while developing compressed ODTs.
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There is an ongoing debate over the use of pharmaceutical excipients in medicines for children, triggered by the increased number of formulations suitable for this target patient population. Pharmaceutical excipients can be regarded as essential / necessary enablers in formulation development. These are materials other than the 'active pharmaceutical ingredient' which are added to the formulation to achieve a specific function1. This may include aiding in the processing or manufacture of the drug delivery system such as lubricants or flow aids, controlling the release of the active ingredient to achieve modified release, enhance patient acceptability by improving taste of medicines or to develop easily swallowed dosage forms.
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Purpose: Technological devices such as smartphones and tablets are widely available and increasingly used as visual aids. This study evaluated the use of a novel app for tablets (MD_evReader) developed as a reading aid for individuals with a central field loss resulting from macular degeneration. The MD_evReader app scrolls text as single lines (similar to a news ticker) and is intended to enhance reading performance using the eccentric viewing technique by both reducing the demands on the eye movement system and minimising the deleterious effects of perceptual crowding. Reading performance with scrolling text was compared with reading static sentences, also presented on a tablet computer. Methods: Twenty-six people with low vision (diagnosis of macular degeneration) read static or dynamic text (scrolled from right to left), presented as a single line at high contrast on a tablet device. Reading error rates and comprehension were recorded for both text formats, and the participant’s subjective experience of reading with the app was assessed using a simple questionnaire. Results: The average reading speed for static and dynamic text was not significantly different and equal to or greater than 85 words per minute. The comprehension scores for both text formats were also similar, equal to approximately 95% correct. However, reading error rates were significantly (p=0.02) less for dynamic text than for static text. The participants’ questionnaire ratings of their reading experience with the MD_evReader were highly positive and indicated a preference for reading with this app compared with their usual method. Conclusions: Our data show that reading performance with scrolling text is at least equal to that achieved with static text and in some respects (reading error rate) is better than static text. Bespoke apps informed by an understanding of the underlying sensorimotor processes involved in a cognitive task such as reading have excellent potential as aids for people with visual impairments.
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Grewia gum was extracted from the inner stem bark of Grewia mollis and characterized by several techniques such as gas chromatography (GC), gel permeation chromatography (GPC), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis of the extracted sample. Spectroscopic techniques such as x-ray photoelectron spectroscopy (XPS), fourier-transformed infrared (FT-IR), solid-state nuclear magnetic resonance (NMR), and 1H and 13C NMR techniques were also used to characterize the gum. The results showed that grewia gum is a typically amorphous polysaccharide gum containing glucose, rhamnose, galactose, arabinose and xylose as neutral sugars. It has an average molecular weight of 5925 kDa expressed as the pullulan equivalent. The gum slowly hydrated in water, dispersing and swelling to form a highly viscous dispersion exhibiting pseudoplastic flow behaviour. The polysaccharide gum is thermally stable and may have application as stabilizer or suspending agent in foods, cosmetics and in pharmaceuticals. It may have application as a binder or sustained-release polymer matrix in tablets or granulations. © IPEC-Americas Inc.
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Kloosterman, D. (2016). Tablets als Wondermiddel voor de Motivatie? Een onderzoek naar de invloed een gesloten tabletsysteem op motivatie van leerlingen. mei, 24, 2016, Heerlen, Nederland: Open Universiteit.
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Augmented Reality (AR) applications often require knowledge of the user’s position in some global coordinate system in order to draw the augmented content to its correct position on the screen. The most common method for coarse positioning is the Global Positioning System (GPS). One of the advantages of GPS is that GPS receivers can be found in almost every modern mobile device. This research was conducted in order to determine the accuracies of different GPS receivers. The tests included seven consumer-grade tablets, three external GPS modules and one professional-grade GPS receiver. All of the devices were tested with both static and mobile measurements. It was concluded that even the cheaper external GPS receivers were notably more accurate than the GPS receivers of the tested tablets. The absolute accuracy of the tablets is difficult to determine from the test results, since the results vary by a large margin between different measurements. The accuracy of the tested tablets in static measurements were between 0.30 meters and 13.75 meters.
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Objectives This study was an in-vitro evaluation of different brands of paracetamol and cotrimoxazole tablets, used or found in Malawi, based on Pharmacopoeia standards, in order to ascertain the existence and extent of substandard medicines in Malawi and to give an overview of their distribution in the public and private sectors. Methodology A cross-sectional analytical study was conducted using 11 samples each of paracetamol and cotrimoxazole tablets. Stratified random sampling was used to collect samples. Samples were analyzed using HPLC and Spectrophometric methods as outlined in the BP-2007 and USP-32 at the National Drug Quality Control Laboratory (NDQCL)-Lilongwe (under Pharmacy Medicines and Poisons Board-PMPB) and Orient Pharma Co. Ltd of Taiwan. The results were analyzed using Epi Info. Results and discussion Fifty percent of samples (n=22) were not registered in the country by the PMPB as required by the PMP Act with the majority of those coming from public health facilities. All paracetamol and cotrimoxazole samples complied with identification tests using spectrophotometric and HPLC method. Overall, 27.3% of samples failed to meet the BP-2007 standards for Active Ingredient content, while 22.7% of the samples failed the Friability test. The results from Malawi are similar in magnitude to those within surrounding countries in Africa. Conclusion This pilot study provides objective evidence to show that substandard and unregistered paracetamol and cotrimoxazole are present and being used in Malawi, and thus posing a considerable hazard to public health in Malawi. PMPB, together with the Ministry of Health, must continue to develop a quality assurance system to ensure that medicines are randomly and routinely checked.
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Purpose: To develop and optimise some variables that influence fluoxetine orally disintegrating tablets (ODTs) formulation. Methods: Fluoxetine ODTs tablets were prepared using direct compression method. Three-factor, 3- level Box-Behnken design was used to optimize and develop fluoxetine ODT formulation. The design suggested 15 formulations of different lubricant concentration (X1), lubricant mixing time (X2), and compression force (X3) and then their effect was monitored on tablet weight (Y1), thickness (Y2), hardness (Y3), % friability (Y4), and disintegration time (Y5). Results: All powder blends showed acceptable flow properties, ranging from good to excellent. The disintegration time (Y5) was affected directly by lubricant concentration (X1). Lubricant mixing time (X2) had a direct effect on tablet thickness (Y2) and hardness (Y3), while compression force (X3) had a direct impact on tablet hardness (Y3), % friability (Y4) and disintegration time (Y5). Accordingly, Box-Behnken design suggested an optimized formula of 0.86 mg (X1), 15.3 min (X2), and 10.6 KN (X3). Finally, the prediction error percentage responses of Y1, Y2, Y3, Y4, and Y5 were 0.31, 0.52, 2.13, 3.92 and 3.75 %, respectively. Formula 4 and 8 achieved 90 % of drug release within the first 5 min of dissolution test. Conclusion: Fluoxetine ODT formulation has been developed and optimized successfully using Box- Behnken design and has also been manufactured efficiently using direct compression technique.
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The aim of the present study is to examine a group of clay tablets by thin-section petrography and thermogravimetric analysis in order to assess specific problems related to their provenance and manufacture technology. Two sets of documents dating to the fourteenth-thirteenth centuries BC will be considered separately throughout the thesis, with different research questions in mind for each case study. The petrographic data will be compared when possible with the chemical composition of the tablets, determined by pXRF and/or INAA in previous studies. On the whole, this dissertation is an attempt to combine textual, archaeological, petrographic, chemical and thermogravimetric information in order to get a better understanding of the materiality and the historical implications of the objects under examination; Resumo: O objetivo do presente estudo é examinar um grupo de tabuletas de argila por petrografia e análise termogravimétrica, a fim de avaliar problemas específicos relacionados com a sua proveniência e tecnologia de fabricação. Dois conjuntos de documentos que datam dos séculos XIV-XIII a.C. serão considerados separadamente ao longo da tese, com diferentes questões de pesquisa em mente para cada estudo de caso. Os dados petrográficos serão comparados quando possível com a composição química das tabuletas, determinada por pXRF e/ou INAA em estudos anteriores. No seu conjunto, esta dissertação é uma tentativa de combinar informação textual, arqueológica, petrográfica, química e termogravimétrica a fim de obter uma melhor compreensão da composição material e das implicações históricas dos objetos em análise.
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Rationale: Piper methysticum (Kava) has been withdrawn in European, British, and Canadian markets due to concerns over hepatotoxic reactions. The WHO recently recommended research into “aqueous” extracts of Kava. Objective: The objective of this study was to conduct the first documented human clinical trial assessing the anxiolytic and antidepressant efficacy of an aqueous extract of Kava. Design and participants: The Kava Anxiety Depression Spectrum Study was a 3-week placebo-controlled, double-blind crossover trial that recruited 60 adult participants with 1 month or more of elevated generalized anxiety. Five Kava tablets per day were prescribed containing 250 mg of kavalactones/day. Results: The aqueous extract of Kava reduced participants' Hamilton Anxiety Scale score in the first controlled phase by −9.9 (CI = 7.1, 12.7) vs. −0.8 (CI = −2.7, 4.3) for placebo and in the second controlled phase by −10.3 (CI = 5.8, 14.7) vs. +3.3 (CI = −6.8, 0.2). The pooled effect of Kava vs. placebo across phases was highly significant (p < 0.0001), with a substantial effect size (d = 2.24, η² [sub]p[sub] = 0.428). Pooled analyses also revealed highly significant relative reductions in Beck Anxiety Inventory and Montgomery–Asberg Depression Rating Scale scores. The aqueous extract was found to be safe, with no serious adverse effects and no clinical hepatotoxicity. Conclusions: The aqueous Kava preparation produced significant anxiolytic and antidepressant activity and raised no safety concerns at the dose and duration studied. Kava appears equally effective in cases where anxiety is accompanied by depression. This should encourage further study and consideration of globally reintroducing aqueous rootstock extracts of Kava for the management of anxiety.