The influence of fillers on theophylline release from clay matrices

Abstract: The objectives of this study were to investigate the suitability of magnesium aluminium silicate (MAS) (Veegum®) to control drug release of a model drug, theophylline, from tablet matrices. To this end, the performance of three commonly used fillers namely: lactose, microcrystalline cellulose (Avicel PH102; MCC), and pre-gelatinized starch, Starch 1500 PGS), were evaluated against Veegum®. The physico-mechanical properties of the tablet matrices were studied along with dissolution studies to determine the effect of single or binary mixtures of the excipients on the drug release pattern. A DSC hydration methodology was also employed to characterize the states of water present in the tablet matrices and to determine any impact on drug release. Formulations containing MAS alone produced compacts with the lowest hardness (4.5 kp) whereas formulations containing MCC alone produced the hardest tablets (17.2 kp). Dissolution studies suggested that matrices containing MAS alone released the theophylline quickest as compared to lactose, MCC or PGS. It was difficult to establish a trend of the bound and free water states in the tablet matrices; however the formulation containing only MAS had the highest bound water at 29 %. The results therefore show that theophylline does not interact with MAS. As such the dominant factor in controlling drug release using MAS requires interaction or intercalation with a cationic drug. In the absence of this however, other excipients can play a role in controlling drug release. Keywords: Veegum, clay matrices, DSC hydration, Magnesium aluminium silicate, filler

Massachusetts State CIO, Industrial Union Council

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Student Perspectives on How Higher Education in Ireland Can Help Meet the Needs of the Irish Economy

This paper will be in three parts; the first section will examine the current tertiary education situation in Ireland amid the global economic crisis and will review what higher education’s contribution be to help alleviate the crisis. Building stronger links with the academy and the economy to help raise skills, efficiency and productivity is becoming more important in ensuring global competitiveness and retaining equality and accessibility in the academy (see Gaffikin and Morrissey, 2003: 98 [14]). The second section will look at the merge of entrepreneurship and education. As the lifelong learning society is conceptualised largely in terms of maintaining a flexible and competitive economy in the knowledge society, the concept of an entrepreneurial society will be proposed to fill the gap which has emerged since the exit of many international companies for cheaper labour elsewhere. Within all levels of education entrepreneurship should be encouraged and embedded in the curricula from the earliest stages as a prevention rather than cure to the current economic crisis in Ireland. The final section will illustrate a brief analysis of students’ perspectives on how higher education can help meet the ever-changing needs of the Irish economy

Is the Scottish population living dangerously? Prevalence of multiple risk factors: the Scottish Health Survey 2003

<b>Background:</b> Risk factors are often considered individually, we aimed to investigate the prevalence of combinations of multiple behavioural risk factors and their association with socioeconomic determinants.<p></p> <b>Methods:</b> Multinomial logistic regression was used to model the associations between socioeconomic factors and multiple risk factors from data in the Scottish Health Survey 2003. Prevalence of five main behavioural risk factors - smoking alcohol, diet, overweight/obesity, and physical inactivity, and the odds in relation to demographic, individual and area socioeconomic factors.<p></p> <b>Results:</b> Full data were available on 6,574 subjects (80.7% of the survey sample). Nearly the whole adult population (97.5%) reported to have at least one behavioural risk factor; while 55% have three or more risk factors; and nearly 20% have four or all five risk factors. The most important determinants for having four or five multiple risk factors were low educational attainment which conferred around a 3-fold increased odds compared to high education; and residence in the most deprived communities (relative to least deprived) which had greater than 3-fold increased odds.<p></p> <b>Conclusions:</b> The prevalence of multiple behavioural risk factors was high and the prevalence of absence of all risk factors very low. These behavioural patterns were socioeconomically determined. Policy to address factors needs to be joined up and better consider underlying socioeconomic circumstances.<p></p&gt

Anomalous single production of fourth family up type quark associated with neutral gauge bosons at the LHC

From the present limits on the masses and mixings of fourth family quarks, they are expected to have mass larger than the top quark and allow a large range of mixing of the third family. They could also have different dynamics than the quarks of three families of the Standard Model. The single production of the fourth family up type quark t' has been studied via anomalous production process pp-> t'VX (where V=g,Z,\gamma) at the LHC with the center of mass energy of 7 and 14 TeV. The signatures of such process are discussed within both the SM decay modes and anomalous decay modes of t' quarks. The sensitivity to anomalous coupling kappa/Lambda=0.004 TeV^(-1) can be reached at sqrt(s)=14 TeV and L_(int)=100 pb^(-1).Comment: 15 pages, 9 figure

Direct observation of irradiation-induced nanocavity shrinkage in Si

Nanocavities in Si substrates, formed by conventional H implantation and thermal annealing, are shown to evolve in size during subsequent Si irradiation. Both ex situ and in situ analytical techniques were used to demonstrate that the mean nanocavity diameter decreases as a function of Si irradiation dose in both the crystalline and amorphous phases. Potential mechanisms for this irradiation-induced nanocavity evolution are discussed. In the crystalline phase, the observed decrease in diameter is attributed to the gettering of interstitials. When the matrix surrounding the cavities is amorphized, cavity shrinkage may be mediated by one of two processes: nanocavities can supply vacancies into the amorphous phase and/or the amorphous phase may flow plastically into the nanocavities. Both processes yield the necessary decrease in density of the amorphous phase relative to crystalline material

The effects of modularity on effective communication and collaboration

In this article we explore the consequences associated with a lack of coordination between the requirements engineering process and the development process. We conduct a detailed case study of an ICT department of a large European bank that develops software using the agile software development method. Our current study reveals that the application of a modular organizational design in a dynamic agile environment has a negative effect on the communication and coordination between members of different modules. More specifically, the modular design creates both a semantic and a pragmatic boundary among members of different modules, which is primarily caused by the fact that modules have differentiated tasks and often misaligned interests

Generalization of Linearized Gouy-Chapman-Stern Model of Electric Double Layer for Nanostructured and Porous Electrodes: Deterministic and Stochastic Morphology

We generalize linearized Gouy-Chapman-Stern theory of electric double layer for nanostructured and morphologically disordered electrodes. Equation for capacitance is obtained using linear Gouy-Chapman (GC) or Debye-$\rm{\ddot{u}}$ckel equation for potential near complex electrode/electrolyte interface. The effect of surface morphology of an electrode on electric double layer (EDL) is obtained using "multiple scattering formalism" in surface curvature. The result for capacitance is expressed in terms of the ratio of Gouy screening length and the local principal radii of curvature of surface. We also include a contribution of compact layer, which is significant in overall prediction of capacitance. Our general results are analyzed in details for two special morphologies of electrodes, i.e. "nanoporous membrane" and "forest of nanopillars". Variations of local shapes and global size variations due to residual randomness in morphology are accounted as curvature fluctuations over a reference shape element. Particularly, the theory shows that the presence of geometrical fluctuations in porous systems causes enhanced dependence of capacitance on mean pore sizes and suppresses the magnitude of capacitance. Theory emphasizes a strong influence of overall morphology and its disorder on capacitance. Finally, our predictions are in reasonable agreement with recent experimental measurements on supercapacitive mesoporous systems

On the π\pi and KK as qqˉq \bar q Bound States and Approximate Nambu-Goldstone Bosons

We reconsider the two different facets of $\pi$ and $K$ mesons as $q \bar q$ bound states and approximate Nambu-Goldstone bosons. We address several topics, including masses, mass splittings between $\pi$ and $\rho$ and between $K$ and $K^*$, meson wavefunctions, charge radii, and the $K-\pi$ wavefunction overlap.Comment: 15 pages, late