61 research outputs found
Parameters Affecting Genetic Algorithm In Leak Detection By Inverse Transients Analysis
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Formulation, characterisation and stabilisation of buccal films for paediatric drug delivery of omeprazole
This study aimed to develop films for potential delivery of omeprazole (OME) via the buccal mucosa of paediatric patients. Films were prepared using hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), sodium alginate (SA), carrageenan (CA) and metolose (MET) with polyethylene glycol (PEG 400) as plasticiser, OME (model drug) and L-arg (stabiliser). Gels (1% w/w) were prepared at 40°C using water and ethanol with PEG 400 (0–1% w/w) and dried in an oven (40°C). Optimised formulations containing OME and L-arg (1:1, 1:2 and 1:3) were prepared to investigate the stabilisation of the drug. Tensile properties (Texture analysis, TA), physical form (differential scanning calorimetry, DSC; X-ray diffraction, XRD; thermogravimetric analysis, TGA) and surface topography (scanning electron microscopy, SEM) were investigated. Based on the TA results, SA and MET films were chosen for OME loading and stabilisation studies as they showed a good balance between flexibility and toughness. Plasticised MET films were uniform and smooth whilst unplasticised films demonstrated rough lumpy surfaces. SA films prepared from aqueous gels showed some lumps on the surface, whereas SA films prepared from ethanolic gels were smooth and uniform. Drug-loaded gels showed that OME was unstable and therefore required addition of L-arg. The DSC and XRD suggested molecular dispersion of drug within the polymeric matrix. Plasticised (0.5% w/w PEG 400) MET films prepared from ethanolic (20% v/v) gels and containing OME: L-arg 1:2 showed the most ideal characteristics (transparency, ease of peeling and flexibility) and was selected for further investigation
Ciprofloxacin-loaded calcium alginate wafers prepared by freeze-drying technique for potential healing of chronic diabetic foot ulcers
Calcium alginate (CA) wafer dressings were prepared by lyophilization of hydrogels to deliver ciprofloxacin (CIP) directly to the wound site of infected diabetic foot ulcers (DFUs). The dressings were physically characterized by scanning electron microscopy (SEM), texture analysis (for mechanical and in vitro adhesion properties), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Further, functional properties essential for wound healing, i.e., porosity, in vitro swelling index, water absorption (Aw), equilibrium water content (EWC), water vapor transmission rate (WVTR), evaporative water loss (EWL), moisture content, in vitro drug release and kinetics, antimicrobial activity, and cell viability (MTT assay) were investigated. The wafers were soft, of uniform texture and thickness, and pliable in nature. Wafers showed ideal wound dressing characteristics in terms of fluid handling properties due to high porosity (SEM). XRD confirmed crystalline nature of the dressings and FTIR showed hydrogen bond formation between CA and CIP. The dressings showed initial fast release followed by sustained drug release which can inhibit and prevent re-infection caused by both Gram-positive and Gram-negative bacteria. The dressings also showed biocompatibility (> 85% cell viability over 72 h) with human adult keratinocytes. Therefore, it will be a potential medicated dressing for patients with DFUs infected with drug-resistant bacteria
Benefits of ultra-fast-track anesthesia in left ventricular assist device implantation: a retrospective, propensity score matched cohort study of a four-year single center experience
Radial consolidation model incorporating the effects of vacuum preloading and non-Darcian flow
Conceptualizing and measuring strategy implementation – a multi-dimensional view
Through quantitative methodological approaches for studying the strategic management and planning process, analysis of data from 208 senior managers involved in strategy processes within ten UK industrial sectors provides evidence on the measurement properties of a multi-dimensional instrument that assesses ten dimensions of strategy implementation. Using exploratory factor analysis, results indicate the sub-constructs (the ten dimensions) are uni-dimensional factors with acceptable reliability and validity; whilst using three additional measures, and correlation and hierarchical regression analysis, the nomological validity for the multi-dimensional strategy implementation construct was established. Relative importance of ten strategy implementation dimensions (activities) for practicing managers is highlighted, with the mutually and combinative effects drawing conclusion that senior management involvement leads the way among the ten key identified activities vital for successful strategy implementation
Al(III) Coated Wire Selective Electrode Based on 5-Bromo(salicylidene-2-aminothiophenol) Schiff Base as a New Ionophore
A new Al(III) selective membrane based on 5-bromo(salicylidene-2-amino thiophenol) as a neutral carrier in a poly(vinyl chloride) (PVC) matrix is coated on platinum wire to determine trace amounts of Al(III) ion in various samples. The sensor exhibits a good response for Al(III) ion over a wide concentration range of 5.20 × 10-7 to 1.00 × 10-2 M with Nernstian slope of 19.64 ± 0.15 mV decade-1 and low detection limit of 5.01 × 10-7 M. The performance of the sensor is best in the pH range of 4.00-6.50 without any divergence in potential and it also works well in partially non-aqueous medium. The coated wire electrode has a short response time of about 5 s and is stable for at least 2 months. The proposed membrane electrode revealed good selectivity for Al(III) ion over a wide variety of other metal ions. It was successfully applied for determination of Al(III) ion in different real and environmental samples and also as an indicator electrode for potentiometric titration of Al(III) ion with EDTA
The determination of some heavy metals in food samples by flame atomic absorption spectrometry after their separation-preconcentration on bis salicyl aldehyde, 1,3 propan diimine (BSPDI) loaded on activated carbon
A sensitive and simple method for the simultaneous preconcentration of Cr(3+), Fe(3+), Cu(2+), Ni(2+) Co(2+) and Zn(2+) in real samples has been reported. The method is based on the adsorption of analytes on his salicyl aldehyde, 1,3 propan diimine (BSPDI) loaded on activated carbon. The adsorbed metals on modified activated carbon were eluted using 8 mL of 2 mol L(-1) nitric acid in acetone or 10 mL of 4 mol L(-1) HNO(3). The influences of the analytical parameters including pH and sample volume were investigated. The effects of matrix ions on the retentions of the analytes were also examined. The recoveries of analytes were generally quantitative. The method has been successfully applied for these metals content evaluation in some food samples. (c) 2007 Elsevier B.V. All rights reserved
Simultaneous Preconcentration and Determination of Trace Amount of Some Heavy Metal Ions
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