4,466 research outputs found

    Hydrophilic Matrices for Oral Control Drug Delivery

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    Oral controlled drug delivery has gathered tremendous attention over the years due to its many advantages over conventional dosage forms. Polymer-based matrices have become an integral part of the pharmaceutical industry. Hydrophilic matrices are capable of controlling the release of drug over an extended period of time. Hydrophilic polymers, especially the hydrophilic derivatives of cellulose ethers, are frequently used for these applications. Therefore, the objective of this review is to discuss the scientific and physicochemical aspects of these polymeric systems that can affect the drug release from such formulation

    Monitoring urban growth and land use land cover change in Al Ain, UAE using remote sensing and GIS techniques

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    Urbanization and industrialization cause a serious land degradation problem, including an increased pressure on natural resources such as deforestation, rise in temperature and management of water resources. The Urban Heat Island (UHI) effects of urbanization are widely acknowledged. Increase of impervious surface is a surrogate measure of urbanization and their effects on local hydrology is well reported in literature. This study investigates the spatial-temporal dynamics of land use and land cover changes in Al Ain, UAE, from 2006 to 2016. The Landsat images of two different periods, i.e., Landsat ETM of 2006 and Landsat 8 for 2016 were acquired from earth explorer site. Semi-supervised known as the hybrid classification method was used for image classification. The change detection was carried out through post-classification techniques. The study area was categorized into five major classes. These are agriculture, gardens, urban, sandy areas and mixed urban/sandy areas. It was observed that agricultural and urban land increases from 42,560 ha to 45,950 ha (8%) and 8150 ha to 9105 ha (12%), respectively. Consequently, the natural sandy area was reduced. It was also found that the urban area was expanded dramatically in the west and southwest directions. The outcomes of this study would help concerning authorities for a sustainable land and water resources management in the Al Ain region

    Tribo-electric Charging and Adhesion of Cellulose Ethers and their Mixtures with Flurbiprofen

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    The pervasiveness of tribo-electric charge during pharmaceutical processing can lead to the exacerbation of a range of problems including segregation, content heterogeneity and particle surface adhesion. The excipients, hydroxypropyl methylcellulose and methylcellulose, are often used in drug delivery systems and so it is important to understand the impact of associated factors on their charging and adhesion mechanisms, however, little work has been done. Such phenomena become more prominent when excipients are introduced to a powder mixture alongside the active pharmaceutical ingredient(s) (APIs) with inter- and intra-particulate interactions giving rise to electrification and surface adhesion of powder particles. The aim of this study was to understand the impact of material attributes (particle size, hydroxypropyl (Hpo) to methoxyl (Meo) ratio and molecular size) on the charging and adhesion characteristics of cellulose ethers. Furthermore, poorly compactible and highly electrostatically charged drug, flurbiprofen, was used to develop binary powder mixtures having different polymer to drug levels. Subsequently, a relationship between tribo-electric charging and surface adhesion was studied. Charge was induced on powder particles and measured using a custom built device based on a shaking concept consisting of a Faraday cup connected to electrometer. The diversity in physicochemical properties has shown a significant impact on the tribo-electric charging and adhesion behaviour of MC and HPMC. Moreover, the adhesion and electrostatic charge of the API was significantly reduced when MC and HPMC were incorporated. Moreover, tribo-electric charging shows a linear relationship (R2= 0.81-0.98) with particle surface adhesion, however, other factors were also involved. It is anticipated that such reduction in charge and particle surface adhesion would improve flow and compaction properties during processing

    Exchange Rate Misalignment in Pakistan: Evidence from Purchasing Power Parity Theory

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    This paper examines the validity of the purchasing power parity to evaluate whether the Pakrupee vis-à-vis the US-dollar has been overvalued since the introduction of managed floating exchange rate. The Johansen multivariate cointegration technique is applied for the period 1982Q2-2002Q4. A single cointegrating vector is identified whose coefficients conform in broad terms to the restriction implied by the PPP theory, lending support to the interpretation of the model as describing a long-run relationship. This support is reinforced by the results derived from the adjustment coefficient, which is identifies clear short-run tendency for the exchange rate to revert to the equilibrium value defined by the estimated long-run model. Furthermore, exchange rate misalignment is also calculated using the estimated long-run relationship to evaluate whether the Pak-rupee vis-à-vis the US-dollar was undervalued or overvalued since the inception of managed floating exchange rate system. Calculated misalignment shows a substantial undervaluation of the Pak-rupee vis-à-vis the US dollar.Exchange Rate, Pakistan

    Developing Teachers’ Expertise to Teach English Language: An Evaluative Study of Professional Development Programme at Taif University English Language Centre

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    Language teachers need opportunities to enhance and update their language teaching skills. Current researches in English language teaching methodologies have proved that teachers who stay up to date with latest teaching techniques are always efficient. They always need to be trained and aware of how they can continue being effective teachers and cope with relative challenges such as students’ low level of language proficiency, large number of students in class at a time and longer teaching hours. Hence the sole objective of the present research is to evaluate the effectiveness of Professional Development Program (PDP) of Taif University. Seeking for this objective, the researcher collected the data through a questionnaire from the participating teachers both males (50) and females (50). The survey was based on five principles drawn by Loucks-Horsley, et al. (2010).  The respondents acknowledged the utility and importance of continuous up gradation of their professional development and leadership skills. They also acknowledged that PDP provides learning opportunity for them. Furthermore they regarded PDP in line with the TU-ELC mission, goal, and objectives. However, they expressed constraints regarding experimentation of new instructional practices, continuous support and follow-up activities, and a research base similar to the ELC situation, community and context
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