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

Incorporating Crystallographic Orientation in the Development of Resonant Ultrasound Spectroscopy

Resonant ultrasound spectroscopy (RUS) measures the mechanical resonance frequencies of solids and uses computational algorithm to extract a complete set of elastic constants. One of the advantages of the RUS method is its applicability to small single crystals. In the past two decades, the RUS technique has gained more acceptance as a nondestructive method to measure elastic properties. The goal of this project is to measure elastic properties of micro pillars without free-free boundary conditions and arbitrary crystallographic orientations. To achieve this goal we need a capability to measure elastic constants of single crystals with arbitrary crystal orientation relative to sample geometry. The inherent assumptions in conventional RUS algorithm include free boundary condition on the specimen faces and the faces of the specimens are normal/parallel to the principal crystallographic axes. To meet these requirements, a time consuming sample preparation, involving multiple inspections of x-ray Laue back reflection to check the crystallographic orientation, is followed. Such an intensive method is not suitable for many samples in engineering applications. To estimate the elastic constants of such samples, a new RUS algorithm has been developed that incorporates the sample crystallographic orientation expressed in terms of Euler angles. The power of the modified RUS algorithm is demonstrated by applying it to estimate the elastic constants of cubic and hexagonal crystal structure samples with known orientation. The results are compared with literature values. Potential application of the method include estimation of elastic constants and their use as input parameters in models that predicts the mechanical behavior of materials for engineering applications is discussed

Formulation and evaluation of floating mucoadhesive alginate beads for targetingHelicobacter pylori

Objectives: There are various obstacles in the eradication of Helicobacter.pylori (H. pylori) infections, including low antibiotic levels and poor accessibility of the drug at the site of the infection. This study describes the preparation and characterisation of novel floating-mucoadhesive alginate beads loaded with clarithromycin (CMN) for delivery to the gastric mucosa to improve the eradication of this micro-organism. Methods: Calcium alginate beads were prepared by ionotropic gelation. The formulation was modified through addition of oil and coating with chitosan in order to improve floating, mucoadhesion and modify drug release. Key findings: SEM confirmed the sphericity of the beads with X-ray microtomography (XμMT) showing the 3D structure of the beads with the layered internal structure of the bead and the even distribution of the drug within the bead. This formulation combined two gastro-retentive strategies and these formulations produced excellent in vitro floating, mucoadhesive and drug release characteristics. Enhanced stability of the beads in phosphate buffer raises a potential for the modified formulations to be targeted to regions of higher pH within the gastrointestinal tract with a higher pH. Drug release from these beads was sustained through an unstirred mucin layer simulating in vivo conditions under which the H. pylori resides in the gastric mucosa. Conclusions: This novel formulation will ensure retention for a longer period in the stomach than conventional formulations and control drug release, ensuring high local drug concentrations, leading to improved eradication of the bacteria

Towards green computing for Internet of Things: energy oriented path and message scheduling approach

Recently, energy efficiency in sensor enabled wire-less network domain has witnessed significant attention from both academia and industries. It is an enabling technological advancement towards green computing in Internet of Things (IoT) eventually supporting sensor generated big data processing for smart cities. Related literature on energy efficiency in sensor enabled wireless network environments focuses on one aspects either energy oriented path selection or energy oriented message scheduling. The definition of path also varies in literature without considering links towards energy efficiency. In this context, this paper proposes an energy oriented path selection and message scheduling framework for sensor enabled wireless network environments. The technical novelty focuses on effective cooperation between path selection and message scheduling considering links on path, location of message sender, and number of processor in sensor towards energy efficiency. Specifically, a path selection strategy is developed based on shortest path and less number of links on path (SPLL). The location of message sender, and number of processor in specific sensor are utilized for developing a longer hops (LH) message scheduling approach. A system model is presented based on M/M/1 queuing analysis to showcase the effective cooperation of SPLL and LH towards energy efficiency. Simulation oriented comparative performance evaluation attest the energy efficiency of the proposed framework as compared to the state-of-the-art techniques considering number of energy oriented metrics

ANALGESIC EFFECT AND ANTI-INFLAMMATORY ACTIVITY OF AQUEOUS EXTRACT OF BOSWELLIA DALZIELII (BURSERACEAE) STEM BARK

Objective: To evaluate the analgesic effect and anti-inflammatory properties of Boswellia dalzielii (Burseraceae), a medicinal plant commonly used in northern Nigeria as an anti-diarrhoeal, antipyretic, analgesic and anti-inflammatory agent.Methods: Three doses (25 mg/kg, 50 mg/kg and 100 mg/kg) of the crude aqueous extract of Boswellia dalzielii were evaluated for analgesic and anti-inflammatory activities using the acetic acid-induced writhing test, formalin-induced nociception and formalin-induced hind paw oedema in rats. The acute oral toxicity was carried out using the up and down procedure as described by the OECD guidelines.Results: All doses (25, 50 and 100 mg/kg) of the extract tested were effective against acetic acid induced abdominal constrictions producing a percentage inhibition of (55.43, 69.56 and 71.73%) respectively. A percentage inhibition of the formalin-induced nociception of (7.31, 31.70 and 48.78%-early phase) and (12.82, 21.79 and 48.71%-late phase) respectively was also produced. For the acetic acid writhing test, the percentage inhibition obtained at the dose of 50 and 100 mg/kg (69.56 and 71.73%) were higher than that of the standard drug (Piroxicam, 10 mg/kg) (59.78%). For formalin-induced nociception, the test extract at 100 mg/kg showed a higher percentage inhibition compared to Piroxicam, in early (48.78 and 43.90%) and late phase (48.71 and 39.74 %) respectively. The extract, however, did not show a significant activity against formalin-induced paw oedema at all the doses used.Conclusion: The present study demonstrated that Boswellia dalzielii has significant analgesic properties comparable to that of the standard drug (10% Piroxicam), thus validating the traditional claim of its antinociceptive property

STUDIES ON THE ANTIBACTERIAL AND ANTICORROSIVE PROPERTIES OF SYNTHESIZED HYBRID POLYURETHANE COMPOSITES FROM CASTOR SEED OIL

Castor seed oil (Ricinus communis) is a prominent feed stock towards the generation of renewable materials for industrial production. The reach presence of ricinoleic fatty acid at 87.5% provides pendant hydroxyl functional groups, which is an essential site for chemical formulations. This paper presents the synthesis, characterization, and evaluations on antibacterial and anticorrosive activities of synthesized hybrid composites from Ricinus communis seed oil. N,N'-bis(2-hydroxy ethyl)-12-hydroxy Ricinus communis oil fatty amide (HERCA) was synthesized via aminolysis polyol formation route. Upon reacting HERCA with succinic acid at a high temperature of about 145 ºC, a polyesteramide (RCPEA) was formed. This ester product undergoes urethanation and subsequently interfaced with modified hybrid material. The synthesized composites were characterized using spectroscopic methods such as FTIR, 1H-NMR, and 13C-NMR. Selected physicochemical parameters were also carried out on the products. Coating performance on cured resins was examined

Nutrition status of children in a well-child clinic in Lagos Nigeria

The burden of malnutrition is evident around the world and more pronounced in developing countries affecting vulnerable groups such as infants, children under five years of age and pregnant women. This study assessed the nutritional status of infants and children aged 9-59 months who visited a well-child clinic at a teaching hospital in Lagos Nigeria. A descriptive cross-sectional study was conducted on 207 children consecutively recruited at a well-child clinic in 2013. Data was collected using structured interviewer-administered questionnaires. Information collected includes the sociodemographic details of each child and caregiver. In addition, selected anthropometric measurements, biochemical tests comprising serum ferritin and total blood protein levels as well as dietary information for each child participant were obtained by trained data collectors. The sampled children were aged 9-59 months, with slightly over half (53.6%) being 12 months old and above. There were more female children and the number of Fathers 84.1%who had attained tertiary education was higher (84.1%) than that of mothers (76.3%). Serum protein and ferritin levels were less than the normal reference values in 1.8% and 26.2% of the children respectively, while the prevalence of underweight children was 4.9% and 8.1% of the children were overweight based on weight-for-age z-scores. Results from the dietary survey showed that the children consumed fewer proteins than carbohydrates. Furthermore, only 18.8% and 12.6% of parents reported feeding their children fruits and vegetables. Significantly more mothers (97.5%) with tertiary education had children with normal weight for age (P<0.05). Despite the low prevalence of malnutrition among the sampled population, it was found that consumption of fruits and vegetables was low, yet these are major sources of vital micronutrients. Results indicated that the prevalence of malnutrition among the study group was generally low. Therefore, steps must be taken to ensure nutrition specific and nutrition sensitive intervention programs aimed at improving the nutritional status of childrenKey words: Nutritional status, assessment, children, weight, ferritin, protein, diet, malnutrition, clini

Finite Element Modeling of Resonance in Polycrystalline Materials for Resonance Ultrasound Spectroscopy

Validation of models that predict the performance of aerospace engine materials depends on the ability to obtain accurate single crystal elastic constants. Resonance Ultrasound Spectroscopy (RUS) is a nondestructive technique in which the natural resonances of a material are utilized to obtain these constants. Traditional RUS utilizes an analytic approach to determine the resonance frequencies of a specimen given an initial guess set of elastic constants. A nonlinear optimization process then fits the elastic constants to experimentally measured data. This approach is limited both in its ability to handle specimens with complex geometry and to handle polycrystalline materials. These more complex scenarios can be approached by utilizing a finite element forward model to obtain sample resonances. A finite element forward model is being developed utilizing COMSOL Multiphysics to compute specimen resonance frequencies. Elastic constants are obtained utilizing a bounded nonlinear optimization routine in MATLAB by way of COMSOL\u27s LiveLink for MATLAB interface. Validation of this forward model has been performed on single crystal specimens, including a nickel superalloy parallelepiped and a fused silica cylinder with a chamfer, ultimately producing lower residual error after optimization than the traditional RUS approach. Model validation is also being performed on a Nickel Aluminide (NiAl) bicrystal. This paper presents the details of this validation process. Also presented is an examination of error sources and the impact they can play in the ability to accurately obtain elastic constants

A state of the art survey - Impact of cyber attacks on SME's

Corporations and end users are finding it hard to keep their devices safe from the ever evolving and complicated threat of cyber attacks. Currently, with the widespread adoption of the Internet of fiings (IoT), cyber threat is becoming an even greater challenge for both technology providers and consumers. This paper presents a review of the recent and significant cyber security issues a?ecting many areas of digital technology. From IoT devices and smart automobiles to commonly used computers and typical corporate servers, we focus our analysis on current a?ack trends and the e?ects of intrusion on Small and Medium sized Enterprises(SMEs). ?is paper helps to build awareness among non-technical experts, practitioners and researchers about attack and defense strategies in the current digital market. We have created a guide with input from our in-house security researchers and information gathered from the literature to help the reader understand the challenges faced by the IT industry in the future

Internet of Things: Evolution and technologies from a security perspective

© 2019 Elsevier Ltd In recent years, IoT has developed into many areas of life including smart homes, smart cities, agriculture, offices, and workplaces. Everyday physical items such as lights, locks and industrial machineries can now be part of the IoT ecosystem. IoT has redefined the management of critical and non-critical systems with the aim of making our lives more safe, efficient and comfortable. As a result, IoT technology is having a huge positive impact on our lives. However, in addition to these positives, IoT systems have also attracted negative attention from malicious users who aim to infiltrate weaknesses within IoT systems for their own gain, referred to as cyber security attacks. By creating an introduction to IoT, this paper seeks to highlight IoT cyber security vulnerabilities and mitigation techniques to the reader. The paper is suitable for developers, practitioners, and academics, particularly from fields such as computer networking, information or communication technology or electronics. The paper begins by introducing IoT as the culmination of two hundred years of evolution within communication technologies. Around 2014, IoT reached consumers, early products were mostly small closed IoT networks, followed by large networks such as smart cities, and continuing to evolve into Next Generation Internet; internet systems which incorporate human values. Following this evolutionary introduction, IoT architectures are compared and some of the technologies that are part of each architectural layer are introduced. Security threats within each architectural layer and some mitigation strategies are discussed, finally, the paper concludes with some future developments