A pragmatic approach for engineering porous mannitol and mechanistic evaluation of particle performance

The importance of mannitol has increased recently as an emerging diluent for orodispersible dosage forms. The study aims to prepare spray dried mannitol retaining high porosity and mechanical strength for the development of orally disintegrating tablets (ODTs). Aqueous feed of d-mannitol (10% w/v) comprising ammonium bicarbonate, NH4HCO3 (5% w/v) as pore former was spray dried at inlet temperature of 110-170°C. Compacts were prepared at 151MPa and characterized for porosity, hardness and disintegration time. Particle morphology and drying mechanisms were studied using thermal (HSM, DSC and TGA) and polymorphic (XRD) methods. Tablet porosity increased from 0.20±0.002 for pure mannitol to 0.53±0.03 using fabricated porous mannitol. Disintegration time dropped by 50-77% from 135±5.29s for pure mannitol to 75.33±2.52-31.67±1.53s for mannitol 110-170°C. Hardness increased by 150% at 110°C (258.67±28.89N) and 30% at 150°C (152.70±10.58N) compared to pure mannitol tablets (104.17±1.70N). Increasing inlet temperature resulted in reducing tablet hardness due to generation of 'micro-sponge'-like particles exhibiting significant elastic recovery. Impact of mannitol polymorphism on plasticity/elasticity cannot be ruled out as a mixture of α and β polymorphs formed upon spray drying.

Solid oral forms availability in children:a cost saving investigation

AIM: To assess the suitability and potential cost savings, from both the hospital and community perspective, of prescribed oral liquid medicine substitution with acceptable solid forms for children over 2 years. METHOD: Oral liquid medicines dispensed from a paediatric hospital (UK) in 1 week were assessed by screening for existence of the solid form alternative and evaluating the acceptability of the available solid form, firstly related to the prescribed dose and secondly to acceptable size depending on the child's age. Costs were calculated based on providing treatment for 28 days or prescribed duration for short term treatments. RESULTS: Over 90% (440/476) of liquid formulations were available as a marketed solid form. Considering dosage acceptability (maximum of 10% deviation from prescribed dosage or 0% for narrow therapeutic range drugs, maximum tablet divisions into quarters) 80% of liquids could be substituted with a solid form. The main limitation for liquid substitution would be solid form size. However, two-thirds of prescribed liquids could have been substituted with a suitable solid form for dosage and size, with estimated savings being of 5K and 8K in 1 week, respectively based on hospital and community costs, corresponding to a projected annual saving of 238K and 410K (single institution). CONCLUSION: Whilst not all children over 2 years will be able to swallow tablets, drug cost savings if oral liquid formulations were substituted with suitable solid dosage forms would be considerable. Given the numerous advantages of solid forms compared with liquids, this study may provide a theoretical basis for investing in supporting children to swallow tablets/capsules.

A compact, portable and low cost generic interrogation strain sensor system using an embedded VCSEL, detector and fibre Bragg grating

We present a compact, portable and low cost generic interrogation strain sensor system using a fibre Bragg grating configured in transmission mode with a vertical-cavity surface-emitting laser (VCSEL) light source and a GaAs photodetector embedded in a polymer skin. The photocurrent value is read and stored by a microcontroller. In addition, the photocurrent data is sent via Bluetooth to a computer or tablet device that can present the live data in a real time graph. With a matched grating and VCSEL, the system is able to automatically scan and lock the VCSEL to the most sensitive edge of the grating. Commercially available VCSEL and photodetector chips are thinned down to 20 µm and integrated in an ultra-thin flexible optical foil using several thin film deposition steps. A dedicated micro mirror plug is fabricated to couple the driving optoelectronics to the fibre sensors. The resulting optoelectronic package can be embedded in a thin, planar sensing sheet and the host material for this sheet is a flexible and stretchable polymer. The result is a fully embedded fibre sensing system - a photonic skin. Further investigations are currently being carried out to determine the stability and robustness of the embedded optoelectronic components. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

A methodological evaluation and predictive in silico investigation into the multi-functionality of arginine in directly compressed tablets

The acceleration of solid dosage form product development can be facilitated by the inclusion of excipients that exhibit poly-/multi-functionality with reduction of the time invested in multiple excipient optimisations. Because active pharmaceutical ingredients (APIs) and tablet excipients present diverse densification behaviours upon compaction, the involvement of these different powders during compaction makes the compaction process very complicated. The aim of this study was to assess the macrometric characteristics and distribution of surface charges of two powders: indomethacin (IND) and arginine (ARG); and evaluate their impact on the densification properties of the two powders. Response surface modelling (RSM) was employed to predict the effect of two independent variables; Compression pressure (F) and ARG percentage (R) in binary mixtures on the properties of resultant tablets. The study looked at three responses namely; porosity (P), tensile strength (S) and disintegration time (T). Micrometric studies showed that IND had a higher charge density (net charge to mass ratio) when compared to ARG; nonetheless, ARG demonstrated good compaction properties with high plasticity (Y=28.01MPa). Therefore, ARG as filler to IND tablets was associated with better mechanical properties of the tablets (tablet tensile strength (σ) increased from 0.2±0.05N/mm2 to 2.85±0.36N/mm2 upon adding ARG at molar ratio of 8:1 to IND). Moreover, tablets' disintegration time was shortened to reach few seconds in some of the formulations. RSM revealed tablet porosity to be affected by both compression pressure and ARG ratio for IND/ARG physical mixtures (PMs). Conversely, the tensile strength (σ) and disintegration time (T) for the PMs were influenced by the compression pressure, ARG ratio and their interactive term (FR); and a strong correlation was observed between the experimental results and the predicted data for tablet porosity. This work provides clear evidence of the multi-functionality of ARG as filler, binder and disintegrant for directly compressed tablets.

Bound dissipative-pulse evolution in the all-normal dispersion fiber laser using a 45° tilted fiber grating

The formation and evolution of bound dissipative pulses in the all-normal dispersion Yb-fiber laser based on a novel 45° tilted fiber grating (TFG) are first investigated both numerically and experimentally. Based on the nonlinear polarization rotation technique, the TFG and two polarization controllers (PCs) are exploited for stable self-started passive mode locking. Numerical results show that the formation of bound-state pulses in the all-normal dispersion region is the progress of soliton shaping through the dispersive waves and follows the soliton energy quantization effect. Theoretical and experimental results demonstrate that the formation mechanism of bound-state pulses can be attributed to the high pump strength and effective filter bandwidth. The obtained bound-state dissipative pulses with quasi-rectangular spectral profile have fixed pulse separation as a function of pump power. © 2013 Astro Ltd.

A holistic multi evidence approach to study the fragmentation behaviour of crystalline mannitol

Mannitol is an essential excipient employed in orally disintegrating tablets due to its high palatability. However its fundamental disadvantage is its fragmentation during direct compression, producing mechanically weak tablets. The primary aim of this study was to assess the fracture behaviour of crystalline mannitol in relation to the energy input during direct compression, utilising ball milling as the method of energy input, whilst assessing tablet characteristics of post-milled powders. Results indicated that crystalline mannitol fractured at the hydrophilic (011) plane, as observed through SEM, alongside a reduction in dispersive surface energy. Disintegration times of post-milled tablets were reduced due to the exposure of the hydrophilic plane, whilst more robust tablets were produced. This was shown through higher tablet hardness and increased plastic deformation profiles of the post-milled powders, as observed with a lower yield pressure through an out-of-die Heckel analysis. Evaluation of crystal state using x-ray diffraction/differential scanning calorimetry showed that mannitol predominantly retained the β-polymorph; however x-ray diffraction provided a novel method to calculate energy input into the powders during ball milling. It can be concluded that particle size reduction is a pragmatic strategy to overcome the current limitation of mannitol fragmentation and provide improvements in tablet properties.

Message from MultiCom-2012 workshop chairs

Welcome to the Second International Workshop on Multimedia Communications and Networking held in conjunction with IUCC-2012 during 25 June – 27 June 2012 in Liverpool, UK. MultiCom-2012 is dedicated to address the challenges in the areas of elivering multimedia content using modern communication and networking techniques. The multimedia & networking computing domain emerges from the integration of multimedia content such as audio and video with content distribution technologies. This workshop aims to cover contributions in both design and analysis aspects in the context of multimedia, wired/wireless/heterogeneous networks, and quality evaluation. It also intends to bring together researchers and practitioners from academia and industry to share their latest achievements in this field with others and establish new collaborations for future developments. All papers received are peer reviewed by three members of the Technical Programme Committee. The papers are assessed by their originality, technical quality, presentation and relevance to the theme of the workshop. Based on the criteria set, four papers have been accepted for presentation at the workshop and will appear in the IUCC conference proceedings. We would like to take this opportunity to thank the IUCC-2012 Organizing Committee, the TPC members of MultiCom-2012 and the authors for their s upport, dedicated work and contributions. Finally, we look forward to meeting you at the workshop in Liverpool.

Grewia gum 1:some mechanical and swelling properties of compact and film

Purpose: To study the mechanical and dynamic swelling properties of grewia gum, evaluate its compression behaviour and determine the effect of drying methods on its properties. Methods: Compacts (500 mg) of both freeze-dried and air-dried grewia gum were separately prepared by compression on a potassium bromide (KBr) press at different pressures and subjected to Heckel analysis. Swelling studies were performed using 200 mg compacts of the gum (freeze-dried or air-dried) compressed on a KBr press. The mechanical properties of the films of the gum prepared by casting 1 % dispersions of the gum were evaluated using Hounsfield tensiometer. The mechanical properties of grewia gum films were compared with films of pullulan and guar gum which were similarly prepared. The effect of temperature on the water uptake of the compacts was studied and the data subjected to Schott's analysis. Results: Drying conditions had no effect on the yield pressure of the gum compacts as both air-dried and freeze-dried fractions had a yield pressure of 322.6 MPa. The plots based on Schott's equation for the grewia gum samples showed that both samples (freeze-dried and air-dried) exhibited long swelling times. Grewia gum film had a tensile strength of 19.22±3.61 MPa which was similar to that of pullulan films (p > 0.05). It had an elastic modulus of 2.13±0.12 N/mm2 which was significantly lower (p < 0.05) than those of pullulan and guar gum with elastic moduli of 3.33±0.00 and 2.86±0.00 N/mm2, respectively. Conclusion: The type of drying method used does not have any effect on the degree of plasticity of grewia gum compacts. Grewia gum obtained by either drying method exhibited extended swelling duration. Matrix tablet formulations of the gum will likely swell slowly and promote sustained release of drug. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City.

Physicochemical characterization of grewia polysaccharide gum:effect of drying method

Grewia polysaccharide gum, a potential pharmaceutical excipient was extracted from the inner stem bark of Grewia mollis, thereupon drying was achieved by three techniques: air-drying, freeze-drying and spray-drying. Analysis of the monosaccharide composition including 1H and 13C NMR spectroscopic analysis of the polysaccharide gum was carried out. The effect of the drying methods on the physicochemical properties of the gum was evaluated by Fourier transformed infra-red (FT-IR) spectroscopy, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, differential scanning calorimetry and gel permeation chromatography. Monosaccharide sugar analysis revealed that the gum is composed of glucose, rhamnose, galactose, arabinose and xylose as the main neutral sugars. These were supported by the results from 1H and 13C NMR spectroscopic analysis. FT-IR and solid-state NMR results indicated that drying technique has little effect on the structure of the polysaccharide gum but XPS showed that surface chemistry of the gum varied with drying methods. Thermogravimetric analyses showed that oxidation onset varied according to the drying method. The molecular weight was also dependent on the drying technique. For industrial extrapolation, air-drying may be preferable to spray-drying and freeze-drying when relative cost, product stability and powder flow are required, for example in tablet formulation. © 2010 Elsevier Ltd. All rights reserved.

The value of tablets as reading aids for individuals with central visual field loss:an evaluation of eccentric reading with static and scrolling text

Purpose: Technological devices such as smartphones and tablets are widely available and increasingly used as visual aids. This study evaluated the use of a novel app for tablets (MD_evReader) developed as a reading aid for individuals with a central field loss resulting from macular degeneration. The MD_evReader app scrolls text as single lines (similar to a news ticker) and is intended to enhance reading performance using the eccentric viewing technique by both reducing the demands on the eye movement system and minimising the deleterious effects of perceptual crowding. Reading performance with scrolling text was compared with reading static sentences, also presented on a tablet computer. Methods: Twenty-six people with low vision (diagnosis of macular degeneration) read static or dynamic text (scrolled from right to left), presented as a single line at high contrast on a tablet device. Reading error rates and comprehension were recorded for both text formats, and the participant’s subjective experience of reading with the app was assessed using a simple questionnaire. Results: The average reading speed for static and dynamic text was not significantly different and equal to or greater than 85 words per minute. The comprehension scores for both text formats were also similar, equal to approximately 95% correct. However, reading error rates were significantly (p=0.02) less for dynamic text than for static text. The participants’ questionnaire ratings of their reading experience with the MD_evReader were highly positive and indicated a preference for reading with this app compared with their usual method. Conclusions: Our data show that reading performance with scrolling text is at least equal to that achieved with static text and in some respects (reading error rate) is better than static text. Bespoke apps informed by an understanding of the underlying sensorimotor processes involved in a cognitive task such as reading have excellent potential as aids for people with visual impairments.

Optimisation of chromatographic separation of oxidised phospholipids and detection with targeted approaches provides greater coverage of the oxidised lipidome

Phospholipid oxidation by adventitious damage generates a wide variety of products with potentially novel biological activities that can modulate inflammatory processes associated with various diseases. To understand the biological importance of oxidised phospholipids (OxPL) and their potential role as disease biomarkers requires precise information about the abundance of these compounds in cells and tissues. There are many chemiluminescence and spectrophotometric assays available for detecting oxidised phospholipids, but they all have some limitations. Mass spectrometry coupled with liquid chromatography is a powerful and sensitive approach that can provide detailed information about the oxidative lipidome, but challenges still remain. The aim of this work is to develop improved methods for detection of OxPLs by optimisation of chromatographic separation through testing several reverse phase columns and solvent systems, and using targeted mass spectrometry approaches. Initial experiments were carried out using oxidation products generated in vitro to optimise the chromatography separation parameters and mass spectrometry parameters. We have evaluated the chromatographic separation of oxidised phosphatidylcholines (OxPCs) and oxidised phosphatidylethanolamines (OXPEs) using C8, C18 and C30 reverse phase, polystyrene – divinylbenzene based monolithic and mixed – mode hydrophilic interaction (HILIC) columns, interfaced with mass spectrometry. Our results suggest that the monolithic column was best able to separate short chain OxPCs and OxPEs from long chain oxidised and native PCs and PEs. However, variation in charge of polar head groups and extreme diversity of oxidised species make analysis of several classes of OxPLs within one analytical run impractical. We evaluated and optimised the chromatographic separation of OxPLs by serially coupling two columns: HILIC and monolith column that provided us the larger coverage of OxPL species in a single analytical run.

A CSR helye a marketing elméletben

A gazdasági tevékenységek folytatásához kapcsolódó jogi, etikai kérdések régóta foglalkoztatják mind az elméleti kutatókat, mind a gyakorlati szakembereket is. Az elfogadott normák időről időre változnak, az érintettek új dimenziókat emelnek be a vélemények, magatartási keretek kialakítása, formálódása során. Az új irányzatok, megközelítések integrálása azonban nem egyszerű sem az elméletalkotás, sem a gyakorlati megvalósítás szempontjából, mivel a már meglévő gondolati és magatartási struktúrák megváltoztatási kényszerével járnak. A CSR fogalma talán az eddigieknél jóval erőteljesebben honosodott meg az üzleti szaknyelvben, de definiálása, elméleti szintézise a kapcsolódó fogalmakkal és mindezek gyakorlati megvalósítása jelenleg még meglehetősen divergens. Az előadás során arra teszünk kísérletet, hogy áttekintsük a CSR szakirodalmi értelmezését és meghatározzuk a lehetséges kapcsolódási pontjait a jelenleg elfogadott marketing fogalmi struktúrákhoz. / === / Both theorists and practitioners have been interested in legal and ethical issues regarding business activities for a long time. The socially accepted norms are changing time by time; new dimensions are being revealed and becoming coherent parts of the constantly formulating views and frames of the expected behaviour. The integration of new streams and approaches however is not an easy process from the respect of both theorydevelopment and practical implementation, as it forces the transformation of the rigid cognitive and behavioural structures. Today CSR has become most widely internalised in business terminology but both its definition and its theoretical synthesis with relating concepts and the way how it is applied in practice have remained divergent. The presentation attempts to provide a literature review focusing on different explanations and determine the possible relationship with the currently accepted marketing theories and conceptual frameworks.

A mozgókép reneszánsza: nagytotál a videográfia módszertanáról = The renaissance of the motion pictures: wide shot of the videography

A posztmodern fogyasztó hiperreális környezetébe csöppenő pozitivista kutató gyakran megtántorodik attól a forgószélszerű pörgéstől és vizuális dinamikától, amelyet a posztmodern világ ont rá. A szupersztrádán teknős módjára kullogó kutató ezért inkább visszahúzódik páncélja mögé, és előhúz valamit a szokásos módszerek közül, függetlenül attól, hogy azok relevánsak-e a probléma vizsgálatára vagy sem. A mozgóképek újjászületése a megváltozott fogyasztói látásmódhoz kapcsolható. Dziga Vertov mechanisztikus szemével egyre inkább a fogyasztók kacsintgatnak, és a curlingben látható módon csúsztatják tovább a magáról megfeledkező és kőnek látszó teknőst. A videográfia a videó és az etnográfia szavak összekapcsolásából keletkezett, vagyis etnográfiai kutatás a mozgókép segítségével. Egyre több nyugati cég arra kéri fel a kutatókat, hogy a fogyasztói magatartásról csupán videó prezentációt készítsenek, mindenféle szöveges magyarázat nélkül. A cikk nagytotálból mutatja be a Belk és Kozinets (2005, 2006) által életre keltett módszertan sajátosságait. / === / The positivist researcher in the middle of the hyperreal context seems to lurch due to the tornado-like whirl and a visual dynamism caused by the postmodern world. This researcher is just like a paddling tortoise on the superhighway draws back in the tortoiseshell and shows one of the classic research methods, no matter the type of the research problem. The rebirth of the motion pictures is linked to the altered consumer perspective. Dziga Vertov’s mechanical eye is used more and more by the consumers, and the tortoise-like researcher is considered to be a curling stone. The consumer researchers tend to ignore the lived visual and auditory aspects of the consumer culture and the appropriate research methods of this field. The aim of this article is to present the types and the main features of the videography vivified by Belk and Kozinets (2005, 2006).