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

Challenges in Developing Applications for Aging Populations

Elderly individuals can greatly benefit from the use of computer applications, which can assist in monitoring health conditions, staying in contact with friends and family, and even learning new things. However, developing accessible applications for an elderly user can be a daunting task for developers. Since the advent of the personal computer, the benefits and challenges of developing applications for older adults have been a hot topic of discussion. In this chapter, the authors discuss the various challenges developers who wish to create applications for the elderly computer user face, including age-related impairments, generational differences in computer use, and the hardware constraints mobile devices pose for application developers. Although these challenges are concerning, each can be overcome after being properly identified

Predictors of anemia in preschool children: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project.

Background: A lack of information on the etiology of anemia has hampered the design and monitoring of anemia-control efforts.Objective: We aimed to evaluate predictors of anemia in preschool children (PSC) (age range: 6-59 mo) by country and infection-burden category.Design: Cross-sectional data from 16 surveys (n = 29,293) from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project were analyzed separately and pooled by category of infection burden. We assessed relations between anemia (hemoglobin concentration <110 g/L) and severe anemia (hemoglobin concentration <70 g/L) and individual-level (age, anthropometric measures, micronutrient deficiencies, malaria, and inflammation) and household-level predictors; we also examined the proportion of anemia with concomitant iron deficiency (defined as an inflammation-adjusted ferritin concentration <12 μg/L). Countries were grouped into 4 categories on the basis of risk and burden of infectious disease, and a pooled multivariable logistic regression analysis was conducted for each group.Results: Iron deficiency, malaria, breastfeeding, stunting, underweight, inflammation, low socioeconomic status, and poor sanitation were each associated with anemia in >50% of surveys. Associations between breastfeeding and anemia were attenuated by controlling for child age, which was negatively associated with anemia. The most consistent predictors of severe anemia were malaria, poor sanitation, and underweight. In multivariable pooled models, child age, iron deficiency, and stunting independently predicted anemia and severe anemia. Inflammation was generally associated with anemia in the high- and very high-infection groups but not in the low- and medium-infection groups. In PSC with anemia, 50%, 30%, 55%, and 58% of children had concomitant iron deficiency in low-, medium-, high-, and very high-infection categories, respectively.Conclusions: Although causal inference is limited by cross-sectional survey data, results suggest anemia-control programs should address both iron deficiency and infections. The relative importance of factors that are associated with anemia varies by setting, and thus, country-specific data are needed to guide programs

Solid-state, triboelectrostatic and dissolution characteristics of spray-dried piroxicam-glucosamine solid dispersions

This work explores the use of both spray drying and D-glucosamine HCl (GLU) as a hydrophilic carrier to improve the dissolution rate of piroxicam (PXM) whilst investigating the electrostatic charges associated with the spray drying process. Spray dried PXM:GLU solid dispersions were prepared and characterised (XRPD, DSC, SEM). Dissolution and triboelectric charging was also conducted. The results showed that the spray dried PXM alone, without GLU produced some PXM form II (DSC results) with no enhancement in solubility relative to that of the parent PXM. XRPD results also showed the spray drying process to decrease the crystallinity of GLU and solid dispersions produced. The presence of GLU improved the dissolution rate of PXM. Spray dried PXM: GLU at a ratio of 2:1 had the most improved dissolution. The spray drying process generally yielded PXM-GLU spherical particles of around 2.5 µm which may have contributed to the improved dissolution. PXM showed a higher tendency for charging in comparison to the carrier GLU (- 3.8 versus 0.5 nC/g for untreated material and -7.5 versus 3.1 nC/g for spray dried materials). Spray dried PXM and spray dried GLU demonstrated higher charge densities than untreated PXM and untreated GLU, respectively. Regardless of PXM:GLU ratio, all spray dried PXM:GLU solid dispersions showed a negligible charge density (net-CMR: 0.1 – 0.3 3nC/g). Spray drying of PXM:GLU solid dispersions can be used to produce formulation powders with practically no charge and thereby improving handling as well as dissolution behaviour of PXM

In utero exposure to cigarette smoking, environmental tobacco smoke and reproductive hormones in US girls approaching puberty

BACKGROUND/AIMS: Evidence is unclear whether prenatal smoking affects age at menarche and pubertal development, and its impact upon hormones has not been well studied. We aim to identify potential pathways through which prenatal smoking and environmental tobacco smoke (ETS) affect reproductive hormones in girls approaching puberty. METHODS: We examined the association between prenatal smoking, current ETS and luteinizing hormone (LH) and inhibin B (InB) in 6- to 11-year-old girls in the 3rd National Health and Nutrition Examination Survey, 1988-1994. Parents/guardians completed interviewer-assisted questionnaires on health and demographics at the time of physical examination. Residual blood samples were analyzed for reproductive hormones in 2008. RESULTS: Of 660 girls, 19 and 39% were exposed to prenatal smoke and current ETS, respectively. Accounting for multiple pathways in structural equation models, prenatally exposed girls had significantly lower LH (β = -0.205 log-mIU/ml, p < 0.0001) and InB (β = -0.162, log-pg/ml, p < 0.0001). Prenatal smoking also influenced LH positively and InB negatively indirectly through BMI-for-age. ETS was positively associated with LH, but not with InB. CONCLUSION: Exposure to maternal smoking may disrupt reproductive development manifesting in altered hormone levels near puberty

Implications of the Different Experiences of Corruption on Police Confidence and Legitimacy in Ghana: An Exploratory Study.

Based on 6 months of fieldwork and conducting 9 sets of observation in Ghana, this thesis explores the effects of the different corruption experiences upon confidence in the police as well as police legitimacy. Since Tyler published his seminal work Why People Obey the Law, legitimacy and confidence in the criminal justice system has become an important concept in criminological analysis. Various studies have sought to clarify the meaning of legitimacy and to examine the factors that influence public perceptions of police legitimacy and confidence. Studies have emphasized the importance of procedural justice, distributive justice, and effectiveness of legal institutions. What remains under-researched in criminological discourse however, is the effects of police corruption upon public confidence and police legitimacy. An important exception is Tankebe’s (2010a) and Asif, Bradford and Zakar’s (2014) study. Yet both construct their study on a simple distinction between direct and indirect experiences of public corruption with the police. This overlooks the fact that there could be different types of direct and vicarious experiences (e.g. negative and positive experiences), with different effects on confidence and legitimacy. This study addresses these issues by examining the effects of both perceptions and different experiences of public-police corruption in Ghana. The research is focused on the experiences of corruption at the street level. Data was obtained from the police and retired police officers, commercial drivers, and private entrepreneurs (market traders). These actors encounter the police more often than any other, and that their expectations in corrupt encounters are conflicting. For example, while some members of the public condemn police corruption at police checkpoints, others, or the same people, in turn criticise and get infuriated at commercial drivers for failing to pay bribes to the police resulting in, for instance, unnecessary journey delays. The impact of these experiences on citizens’ perceptions of police legitimacy and confidence in the Ghanaian police are discussed

A Modular, Low-Cost Ka-Band Antenna Subarray as Building Block for Phased Arrays of Arbitrary Size and Shape

Recent and upcoming megaconstellations in LEO orbit will contribute to suppress the digital divide through satellite communication (satcom). The big obstacle, for an even more widespread use, is currently represented by the user terminal. The everyday consumer has still to deal with high power consumption and cost, exhibited by existing phased array-based antenna solutions. In this paper, a cost-effective phased array modular antenna concept, based on domino subarrays, is presented. The domino subarrays can be deployed in an arbitrary size and shape, opening to fully customizable phased arrays which can accommodate different designs for the upcoming 6G applications.</p

Assessing Municipal Solid Waste Management Practices and Challenges in the Techiman Municipality, Ghana

Managing waste efficiently is essential for building sustainable, livable and healthy communities but this remains a challenge for many municipal governments due to limited municipal budget and other logistical challenges. Such challenges result in ineffective waste collection and disposal. However, identifying the challenges associated with municipal solid waste management often lead to developing solutions to mitigate the problem. This paper assesses the waste management practices and challenges within the Techiman municipality, the regional capital of the Bono East Region. By sampling residents’ perceptions and experiences it was observed that households and patrons were dissatisfied with Techiman’s Municipal Solid Waste Management (MSWM). Statistically the per capita per day rate of waste generation was 0.48kg/ per capita/per day, being higher than Ghana’s municipal waste generation of 0.40 kg/per capita/per day. Lack of collection of waste from the transfer stations to the landfill sites has resulted in about 67 heaps of uncollected waste in the municipality. The results show that lack of source separation and recycling, broken down trucks, low participation of private sector in waste collection, non-compliance of by-laws, poor road infrastructure leading to the landfill site, and inefficient landfill site have contributed to the waste problem in the municipality. Resorting to source separation, educating the public on waste management bye laws, increasing private sector participation and establishing engineered landfill sites can substantially contribute to sustainable Municipal Waste Management in the Techiman Municipality

Improvement of annual forage and seed production in the sub-humid zone of Nigeria through supplement irrigation

A two-year study was conducted at Shika in the Northern Guinea Savanna of Nigeria to evaluate several perennial and annual forage species for seasonal and total annual herbage and/or seed production. Over the entire experimental period, total dry matter (DM) yields for grasses, perennial and hay-suited annual legumes varied from 27.5 to 79.1, 18.8 to 40.3 and 40.5 to 50.5 t/ha, to which irrigation contributed 48 to 66, 50 to 57 and 56 % respectively. Irrigated grass crude protein (CP) contents averaged 5.3 and 9.9 %; and legume CP contents 16.1 and 18.8 % for the May and December harvests while rainfed grass CP contents ranged from 7.7 % (August) to 10.9 % (October), the corresponding legume values being 18.7 and 20.9 %. Irrigated cropping accounted for 55 to 56 % of the 9 207 to 12 461 kg/ha seed yield recorded in dual purpose legumes. It was inferred that on the basis of total herbage yield, distribution of yield and responsiveness to irrigation Pennisetum purpureum, Brachiaria decumbens, Cajanus cajan Acc UQ 50 or 3D 8104 and S. guianensis cv Cook proved to be promising; reasonable seed yield levels were obtained from C. cajan 3D 8104, Glycine max Acc. 49-14 and M 216 and Vigna unguiculata Acc Ivu 1283, whether irrigated or rainfed. The potential of irrigation is discussed in relation to feed, food and livestock production

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