Evaluation of sesamum gum as an excipient in matrix tablets

In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd

Genetic relationship between schizophrenia and nicotine dependence

Contains fulltext : 157529.pdf (publisher's version ) (Open Access)It is well known that most schizophrenia patients smoke cigarettes. There are different hypotheses postulating the underlying mechanisms of this comorbidity. We used summary statistics from large meta-analyses of plasma cotinine concentration (COT), Fagerström test for nicotine dependence (FTND) and schizophrenia to examine the genetic relationship between these traits. We found that schizophrenia risk scores calculated at P-value thresholds of 5 × 10−3 and larger predicted FTND and cigarettes smoked per day (CPD), suggesting that genes most significantly associated with schizophrenia were not associated with FTND/CPD, consistent with the self-medication hypothesis. The COT risk scores predicted schizophrenia diagnosis at P-values of 5 × 10−3 and smaller, implying that genes most significantly associated with COT were associated with schizophrenia. These results implicated that schizophrenia and FTND/CPD/COT shared some genetic liability. Based on this shared liability, we identified multiple long non-coding RNAs and RNA binding protein genes (DA376252, BX089737, LOC101927273, LINC01029, LOC101928622, HY157071, DA902558, RBFOX1 and TINCR), protein modification genes (MANBA, UBE2D3, and RANGAP1) and energy production genes (XYLB, MTRF1 and ENOX1) that were associated with both conditions. Further analyses revealed that these shared genes were enriched in calcium signaling, long-term potentiation and neuroactive ligand-receptor interaction pathways that played a critical role in cognitive functions and neuronal plasticity.10 p

Board Share-Ownership and Takeover Performance

We investigate the relation between takeover performance and board share-ownership in the acquiring company for a sample of 363 UK takeovers completed in the period 1985-96. In investigating this relationship we pay particular attention to the composition of board shareholdings as well as their size. Thus, in addition to the analysis of total board holdings, we analyse the separate impact of CEO shareholdings and of the pattern of non-executive and executive holdings within the board. In addition to our detailed examination of board holdings we assess the impact of non-board holdings. Our analysis controls for a number of non-shareholding constraints on discretionary director behaviour and for a variety of other influences on takeover outcomes including: the means of payment; acquirer size and market to book value; the relative size of the acquirer and the target; the nature of the bid in terms of hostility and industrial direction; and the pre-takeover performance of the acquiring company. We assess performance in terms of announcement returns, long run share returns and a portfolio of accounting measures. We find evidence that overall board ownership has a strong positive impact on long run share returns and a weak positive impact on operating performance. However, much stronger effects are found when the overall board measure is split into CEO, executive, and non-executive directors. We find strong evidence of a positive relation between takeover performance and CEO ownership, which holds for both long run returns and operating performance measures. This finding is robust to controlling for other factors that determine takeover performance and holds in a two stage least squares framework that controls for endogeneity effects. Shareholdings of other executive directors, non-executive directors, and non-board holdings are found to have no significant effect on takeover performance. Copyright Blackwell Publishers Ltd, 2006.