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Sample records for model tablet systems

  1. Multivariate modelling of the tablet manufacturing process with wet granulation for tablet optimization and in-process control

    NARCIS (Netherlands)

    Westerhuis, J.A; Coenegracht, P.M J; Lerk, C.F

    1997-01-01

    The process of tablet manufacturing with granulation is described as a two-step process. The first step comprises wet granulation of the powder mixture, and in the second step the granules are compressed into tablets. For the modelling of the pharmaceutical process of wet granulation and tableting,

  2. Tableting process optimisation with the application of fuzzy models.

    Science.gov (United States)

    Belic, Ales; Skrjanc, Igor; Bozic, Damjana Zupancic; Vrecer, Franc

    2010-04-15

    A quality-by-design (QbD) principle, including process analytical technology, is becoming the principal idea in drug development and manufacturing. The implementation of QbD into product development and manufacturing requires larger resources, both human and financial, however, large-scale production can be established in a more cost-effective manner and with improved product quality. The objective of the present work was to study the influence of particle size distribution in powder mixture for tableting, and the settings of the compression parameters on the tablet quality described by the capping coefficient, standard deviations of mass and crushing strength of compressed tablets. Fuzzy models were used for modelling of the effects of the particle size distribution and the tableting machine settings on the tablet quality. The results showed that the application of mathematical models, based on the contemporary routinely measured quantities, can significantly improve the trial-and-error procedures.

  3. Development of an automation system for a tablet coater

    DEFF Research Database (Denmark)

    Ruotsalainen, Mirja; Heinämäki, Jyrki; Rantanen, Jukka

    2002-01-01

    An instrumentation and automation system for a side-vented pan coater with a novel air-flow rate measurement system for monitoring the film-coating process of tablets was designed and tested. The instrumented coating system was tested and validated by film-coating over 20 pilot-scale batches...... of tablets with aqueous-based hydroxypropyl methylcellulose (HPMC). Thirteen different process parameters were continuously measured and monitored, and the most significant ones were logged for analysis. Laser profilometry was used to measure the surface roughness of the coated tablets. The instrumentation...... system provided comprehensive and quantitative information on the process parameters monitored. The measured process parameters and the responses of the film-coated tablet batches showed that the coating process is reproducible. The inlet air-flow rate influenced the coating process and the subsequent...

  4. A Community of Practice Model for Introducing Mobile Tablets to University Faculty

    Science.gov (United States)

    Drouin, Michelle; Vartanian, Lesa Rae; Birk, Samantha

    2014-01-01

    We examined the effectiveness of a community of practice (CoP) model for introducing tablets to 139 faculty members at a higher education institution. Using a CoP within a systems model, we used large- and small-group mentorship to foster collaboration among faculty members. Most faculty members agreed that the project was well organized and…

  5. Interactive Rhythm Learning System by Combining Tablet Computers and Robots

    Directory of Open Access Journals (Sweden)

    Chien-Hsing Chou

    2017-03-01

    Full Text Available This study proposes a percussion learning device that combines tablet computers and robots. This device comprises two systems: a rhythm teaching system, in which users can compose and practice rhythms by using a tablet computer, and a robot performance system. First, teachers compose the rhythm training contents on the tablet computer. Then, the learners practice these percussion exercises by using the tablet computer and a small drum set. The teaching system provides a new and user-friendly score editing interface for composing a rhythm exercise. It also provides a rhythm rating function to facilitate percussion training for children and improve the stability of rhythmic beating. To encourage children to practice percussion exercises, a robotic performance system is used to interact with the children; this system can perform percussion exercises for students to listen to and then help them practice the exercise. This interaction enhances children’s interest and motivation to learn and practice rhythm exercises. The results of experimental course and field trials reveal that the proposed system not only increases students’ interest and efficiency in learning but also helps them in understanding musical rhythms through interaction and composing simple rhythms.

  6. Tablet PC Enabled Body Sensor System for Rural Telehealth Applications

    Directory of Open Access Journals (Sweden)

    Nitha V. Panicker

    2016-01-01

    Full Text Available Telehealth systems benefit from the rapid growth of mobile communication technology for measuring physiological signals. Development and validation of a tablet PC enabled noninvasive body sensor system for rural telehealth application are discussed in this paper. This system includes real time continuous collection of physiological parameters (blood pressure, pulse rate, and temperature and fall detection of a patient with the help of a body sensor unit and wireless transmission of the acquired information to a tablet PC handled by the medical staff in a Primary Health Center (PHC. Abnormal conditions are automatically identified and alert messages are given to the medical officer in real time. Clinical validation is performed in a real environment and found to be successful. Bland-Altman analysis is carried out to validate the wrist blood pressure sensor used. The system works well for all measurements.

  7. KINETICS STUDY ON KETOPROFEN RELEASE FROM MINI TABLETS AND MULTI-COMPARTMENT SYSTEMS.

    Science.gov (United States)

    Stawarski, Tomasz; Sieradzki, Edmund; Gałecka, Emilia; Binek, Karolina

    2016-01-01

    Thanks to multi-compartment systems it is possible to modify drug release. Two types of mini tablets containing 12.5 mg of ketoprofen were made: mini tablets of immediate (IR) and sustained (SR) release. Some of the tablets of immediate release were coated with an enteric coating, thereby obtaining a delayed release effect (IRc). For each tablet type, release profiles were tested in three media: 0.1 M HCl, phosphate buffer pH 4.5 and phosphate buffer pH 6.8. Based on the obtained results, three appropriate multi-compartment models have been constructed and tested. The factor limiting the amount of available ketoprofen at the absorption place is pH of the environment. It was observed that the increase in pH caused the increase of ketoprofen solubility. Constructed multi-compartment systems allowed to change the composition and the dose of medicinal substances easily. Thanks to this it is possible to adjust the release profile of the active substance to the individual patient, which meets the expectations of personalized medicine.

  8. An exact model for predicting tablet and blend content uniformity based on the theory of fluctuations in mixtures.

    Science.gov (United States)

    Rane, Sagar S; Hamed, Ehab; Rieschl, Sarah

    2012-12-01

    Content uniformity (CU) of tablets is a critical property that needs to be well controlled in pharmaceutical products. Methods that predict the CU accurately can greatly help in reducing the development efforts. This article presents a statistical mechanical framework for predicting CU based on first principles at the molecular level. The tablet is modeled as an open system that can be treated as a grand canonical ensemble to calculate fluctuations in the number of granules and thus the CU. Exact analytical solutions to hard sphere mixture systems are applied to derive an expression for the CU and elucidate the different factors that impact CU. The model was tested against literature data and a large set of tablet formulations specifically made and analyzed for CU using a model active pharmaceutical ingredient. The formulations covered the effect of granule size, percentage loading, and tablet weight on the CU. The model is able to predict the mean experimental coefficient of variation (CV) with good success and captures all the elements that impact the CU. The predictions of the model serve as a theoretical lower limit for the mean CV (for infinite batches or tablets) that can be expected during manufacturing assuming the best processing conditions.

  9. The Virtual Tablet: Virtual Reality as a Control System

    Science.gov (United States)

    Chronister, Andrew

    2016-01-01

    In the field of human-computer interaction, Augmented Reality (AR) and Virtual Reality (VR) have been rapidly growing areas of interest and concerted development effort thanks to both private and public research. At NASA, a number of groups have explored the possibilities afforded by AR and VR technology, among which is the IT Advanced Concepts Lab (ITACL). Within ITACL, the AVR (Augmented/Virtual Reality) Lab focuses on VR technology specifically for its use in command and control. Previous work in the AVR lab includes the Natural User Interface (NUI) project and the Virtual Control Panel (VCP) project, which created virtual three-dimensional interfaces that users could interact with while wearing a VR headset thanks to body- and hand-tracking technology. The Virtual Tablet (VT) project attempts to improve on these previous efforts by incorporating a physical surrogate which is mirrored in the virtual environment, mitigating issues with difficulty of visually determining the interface location and lack of tactile feedback discovered in the development of previous efforts. The physical surrogate takes the form of a handheld sheet of acrylic glass with several infrared-range reflective markers and a sensor package attached. Using the sensor package to track orientation and a motion-capture system to track the marker positions, a model of the surrogate is placed in the virtual environment at a position which corresponds with the real-world location relative to the user's VR Head Mounted Display (HMD). A set of control mechanisms is then projected onto the surface of the surrogate such that to the user, immersed in VR, the control interface appears to be attached to the object they are holding. The VT project was taken from an early stage where the sensor package, motion-capture system, and physical surrogate had been constructed or tested individually but not yet combined or incorporated into the virtual environment. My contribution was to combine the pieces of

  10. Development and evaluation of natural gum-based extended release matrix tablets of two model drugs of different water solubilities by direct compression.

    Science.gov (United States)

    Ofori-Kwakye, Kwabena; Mfoafo, Kwadwo Amanor; Kipo, Samuel Lugrie; Kuntworbe, Noble; Boakye-Gyasi, Mariam El

    2016-01-01

    The study was aimed at developing extended release matrix tablets of poorly water-soluble diclofenac sodium and highly water-soluble metformin hydrochloride by direct compression using cashew gum, xanthan gum and hydroxypropylmethylcellulose (HPMC) as release retardants. The suitability of light grade cashew gum as a direct compression excipient was studied using the SeDeM Diagram Expert System. Thirteen tablet formulations of diclofenac sodium (∼100 mg) and metformin hydrochloride (∼200 mg) were prepared with varying amounts of cashew gum, xanthan gum and HPMC by direct compression. The flow properties of blended powders and the uniformity of weight, crushing strength, friability, swelling index and drug content of compressed tablets were determined. In vitro drug release studies of the matrix tablets were conducted in phosphate buffer (diclofenac: pH 7.4; metformin: pH 6.8) and the kinetics of drug release was determined by fitting the release data to five kinetic models. Cashew gum was found to be suitable for direct compression, having a good compressibility index (ICG) value of 5.173. The diclofenac and metformin matrix tablets produced generally possessed fairly good physical properties. Tablet swelling and drug release in aqueous medium were dependent on the type and amount of release retarding polymer and the solubility of drug used. Extended release of diclofenac (∼24 h) and metformin (∼8-12 h) from the matrix tablets in aqueous medium was achieved using various blends of the polymers. Drug release from diclofenac tablets fitted zero order, first order or Higuchi model while release from metformin tablets followed Higuchi or Hixson-Crowell model. The mechanism of release of the two drugs was mostly through Fickian diffusion and anomalous non-Fickian diffusion. The study has demonstrated the potential of blended hydrophilic polymers in the design and optimization of extended release matrix tablets for soluble and poorly soluble drugs by direct

  11. De-risking pharmaceutical tablet manufacture through process understanding, latent variable modeling, and optimization technologies.

    Science.gov (United States)

    Muteki, Koji; Swaminathan, Vidya; Sekulic, Sonja S; Reid, George L

    2011-12-01

    In pharmaceutical tablet manufacturing processes, a major source of disturbance affecting drug product quality is the (lot-to-lot) variability of the incoming raw materials. A novel modeling and process optimization strategy that compensates for raw material variability is presented. The approach involves building partial least squares models that combine raw material attributes and tablet process parameters and relate these to final tablet attributes. The resulting models are used in an optimization framework to then find optimal process parameters which can satisfy all the desired requirements for the final tablet attributes, subject to the incoming raw material lots. In order to de-risk the potential (lot-to-lot) variability of raw materials on the drug product quality, the effect of raw material lot variability on the final tablet attributes was investigated using a raw material database containing a large number of lots. In this way, the raw material variability, optimal process parameter space and tablet attributes are correlated with each other and offer the opportunity of simulating a variety of changes in silico without actually performing experiments. The connectivity obtained between the three sources of variability (materials, parameters, attributes) can be considered a design space consistent with Quality by Design principles, which is defined by the ICH-Q8 guidance (USDA 2006). The effectiveness of the methodologies is illustrated through a common industrial tablet manufacturing case study.

  12. UV imaging of Multiple Unit Pellet System (MUPS) tablets: A case study of acetylsalicylic acid stability

    DEFF Research Database (Denmark)

    Novikova, Anna; Carstensen, Jens Michael; Rades, Thomas

    2017-01-01

    The applicability of multispectral ultraviolet (UV) imaging in combination with multivariate image analysis was investigated to monitor API degradation within multiple unit pellet system (MUPS) tablets during storage. For this purpose, acetylsalicylic acid (ASA) layered pellets were coated...

  13. Mathematical Model-Based Accelerated Development of Extended-release Metformin Hydrochloride Tablet Formulation.

    Science.gov (United States)

    Chen, W; Desai, D; Good, D; Crison, J; Timmins, P; Paruchuri, S; Wang, J; Ha, K

    2016-08-01

    A computational fluid dynamic (CFD) model was developed to predict metformin release from a hydroxypropylmethylcellulose (HPMC) matrix-based extended-release formulation that took into consideration the physical and chemical properties of the drug substance, composition, as well as size and shape of the tablet. New high dose strength (1000 mg) tablet geometry was selected based on the surface area/volume (SA/V) approach advocated by Lapidus/Lordi/Reynold to obtain the desired equivalent metformin release kinetics. Maintaining a similar SA/V ratio across all extended-release metformin hydrochloride (Met XR) tablet strengths that had different geometries provided similar simulations of dissolution behavior. Experimental dissolution profiles of three lots of high-strength tablets agreed with the simulated release kinetics. Additionally, a pharmacokinetic absorption model was developed using GastroPlus™ software and known physicochemical, pharmacokinetic, and in vitro dissolution properties of metformin to predict the clinical exposure of the new high strength (1000 mg) tablet prior to conducting a human clinical bioequivalence study. In vitro metformin release kinetics were utilized in the absorption model to predict exposures in humans for new 1000-mg Met XR tablets, and the absorption model correctly projected equivalent in vivo exposure across all dose strengths. A clinical bioequivalence study was pursued based on the combined modeling results and demonstrated equivalent exposure as predicted by the simulations.

  14. Fast disintegrating tablets: Opportunity in drug delivery system

    Directory of Open Access Journals (Sweden)

    Ved Parkash

    2011-01-01

    Full Text Available Fast disintegrating tablets (FDTs have received ever-increasing demand during the last decade, and the field has become a rapidly growing area in the pharmaceutical industry. Oral drug delivery remains the preferred route for administration of various drugs. Recent developments in the technology have prompted scientists to develop FDTs with improved patient compliance and convenience. Upon introduction into the mouth, these tablets dissolve or disintegrate in the mouth in the absence of additional water for easy administration of active pharmaceutical ingredients. The popularity and usefulness of the formulation resulted in development of several FDT technologies. FDTs are solid unit dosage forms, which disintegrate or dissolve rapidly in the mouth without chewing and water. FDTs or orally disintegrating tablets provide an advantage particularly for pediatric and geriatric populations who have difficulty in swallowing conventional tablets and capsules. This review describes various formulations and technologies developed to achieve fast dissolution/dispersion of tablets in the oral cavity. In particular, this review describes in detail FDT technologies based on lyophilization, molding, sublimation, and compaction, as well as approaches to enhancing the FDT properties, such as spray drying and use of disintegrants. In addition, taste-masking technologies, experimental measurements of disintegration times, and dissolution are also discussed.

  15. Effect of simulated precompression, compression pressure and tableting speed on an offline diffuse transmittance and reflectance near-infrared spectral information of model intact caffeine tablets.

    Science.gov (United States)

    Vranic, Branko Z; Vandamme, Thierry F

    2015-01-01

    Near-infrared spectroscopy (NIRS) is used in the pharmaceutical industry for monitoring drug content during the tablet manufacturing process. It is of critical importance to understand the effect of process factors on NIRS performance. Design of Experiments (DoE) methodology was applied in this work for the systematic study of the effects of compression pressure, precompression pressure and tableting speed on an average Euclidean distance (AED), which reflects spectral features of the tablets, and root mean-squared error of prediction (RMSEP) as key performance indicator of NIRS calibration models. Caffeine tablets were manufactured in 17 experimental runs in accordance with D-optimal design. Developed diffuse transmittance (DT) and diffuse reflectance (DR) calibration models were tested on five independent test sets to confirm the conclusions of the DoE. Compression pressure and tableting speed have shown significant effect on the studied responses in DT mode, whereas all three studied factors have shown a significant effect in DR mode. Significant factors were considered in the development of the global calibration models. The authors suggest further study of RMSEP and AED responses to draw reliable conclusions on the effects of tableting process factors. The global calibration model in DT mode has shown superior performance compared to DR mode.

  16. Development of a multiparticulate system containing enteric-release mini-tablets of omeprazole

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    Volnei Jose Tondo Filho

    2014-09-01

    Full Text Available The main aim of this study was to develop a multiparticulate system containing mini-tablets of omeprazole formulated with an enteric polymer with pH-dependent solubility. Pre-formulation studies showed good flow and compaction capacity, leading to the production ofhigh quality mini-tablets. The mini-tablets were coated in a fluidized bed with hydroxypropylmethylcellulose /Eudragit(r L30D55 and packed into hard gelatin capsules. The dissolution profile showed gastro-resistance and zero-order kinetics. The dissolution profile for the formulation containing lactose as the diluent and coated with 12% (tablet weight gain of polymer was similar to that ofthe reference drug.

  17. A suppository-base-matrix tablet for time-dependent colon-specific delivery system

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    Meijuan Zou

    2014-09-01

    Full Text Available Our research has focused on the main design features and release performances of time-dependent colon-specific (TDCS delivery tablets, which relies on the relative constancy that is observed in the small intestinal transit time of dosage forms. But inflammatory bowel disease(IBD)can affect the transit time, and usually results in watery stool. Compared to the TDCS and wax-matrix TDCS tablet, a promising time-dependent colon-specific delivery system was investigated. In our study, a suppository-base-matrix coated tablet was evaluated. Water soluble suppository-base helps the expansion of tablet, facilitates uniform film dissolution and achives high osmotic pressure. Combining the expansion of carboxymethyl starch sodium (CMS-Na and the moisture absorption of NaCl, the coated TDCS tablet obtained a burst and targeted drug delivery system. A very good correlation between in vitro drug release and in vivo outcome was observed. This TDCS coated tablet provides a promising strategy to control drug release to the desired lower gastrointestinal region.

  18. Film coating potential of okra gum using paracetamol tablets as a model drug

    Directory of Open Access Journals (Sweden)

    Ogaji Ikoni

    2010-01-01

    Full Text Available The purpose of this work was to study the film coating potential of okra gum extracted from pods of Abelmoschus esculentus plant using paracetamol as a model drug. Core tablets of paracetamol were obtained from a pharmacy shop in the locality and the physicochemical properties such as weight, hardness, friability, and disintegration time were evaluated. Aqueous coating suspensions of okra gum and hydroxypropylmethylcellulose (0.6%w/v were prepared and used to coat the tablets in Hi-coater. The coated tablets were evaluated for weight uniformity, diameter, thickness, hardness, friability, disintegration time, and moisture uptake at controlled humidity. The coating remained intact, durable, and resistant to chipping when challenged to catastrophic fall or rubbed on a white paper. The coated tablets had lower friability, increased disintegration time (24 min compared to the core (3 min and improved hardness, but there was no difference in the dissolution profile of the samples from the batches containing okra and hydroxypropylmethylcellulose as film formers. Changes were observed in some of the physicochemical properties of the formulations containing okra gum as with the known film former and it was convenient to conclude that these changes were due to the effect of the mechanical properties of the film formers. It was our conclusion that okra gum is a promising natural, biodegradable, cheap and eco-friendly film former in aqueous tablet film coating operation, particularly when masking of taste or objectionable odor in a solid dosage formulation is desired.

  19. Tablets of pre-liposomes govern in situ formation of liposomes: concept and potential of the novel drug delivery system.

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    Vanić, Željka; Planinšek, Odon; Škalko-Basnet, Nataša; Tho, Ingunn

    2014-10-01

    The purpose of this study was to develop a novel drug delivery system for challenging drugs with potential for scale-up manufacturing and controlled release of incorporated drug. Pre-liposomes powder containing metronidazole, lecithin and mannitol, prepared by spray-drying, was mixed with different tableting excipients (microcrystalline cellulose, lactose monohydrate, mannitol, dibasic calcium phosphate, pregelatinized starch, pectin or chitosan) and compressed into tablets. The delivery system was characterized with respect to (i) dry powder characteristics, (ii) mechanical tablet properties and drug release, and (iii) liposomal characteristics. The pre-liposomes powder was free-flowing, and tablets of similarly high qualities as tablets made of physical mixtures were prepared with all excipients. Liposomes were formed in situ upon tablet disintegration, dissolution or erosion depending on the type of tablet excipient used. The liposomal characteristics and drug release were found to depend on the tablet excipient. The new delivery system offers a unique synergy between the ability of liposomes to encapsulate and protect drugs and increased stability provided by compressed formulations. It can be adjusted for drug administration via various routes, e.g. oral, buccal and vaginal.

  20. A unified multicomponent stress-diffusion model of drug release from non-biodegradable polymeric matrix tablets.

    Science.gov (United States)

    Salehi, Ali; Zhao, Jin; Cabelka, Tim D; Larson, Ronald G

    2016-02-28

    We propose a new transport model of drug release from hydrophilic polymeric matrices, based on Stefan-Maxwell flux laws for multicomponent transport. Polymer stress is incorporated in the total mixing free energy, which contributes directly to the diffusion driving force while leading to time-dependent boundary conditions at the tablet interface. Given that hydrated matrix tablets are dense multicomponent systems, extended Stefan-Maxwell (ESM) flux laws are adopted to ensure consistency with the Onsager reciprocity principle and the Gibbs-Duhem thermodynamic constraint. The ESM flux law for any given component takes into account the friction exerted by all other species and is invariant with respect to reference velocity, thus satisfying Galilean translational invariance. Our model demonstrates that penetrant-induced plasticization of polymer chains partially or even entirely offsets the steady decline of chemical potential gradients at the tablet-medium interface that drive drug release. Utilizing a Flory-Huggins thermodynamic model, a modified form of the upper convected Maxwell constitutive equation for polymer stress and a Fujita-type dependence of mutual diffusivities on composition, depending on parameters, Fickian, anomalous or case II drug transport arises naturally from the model, which are characterized by quasi-power-law release profiles with exponents ranging from 0.5 to 1, respectively. A necessary requirement for non-Fickian release in our model is that the matrix stress relaxation time is comparable to the time scale for water diffusion. Mutual diffusivities and their composition dependence are the most decisive factors in controlling drug release characteristics in our model. Regression of the experimental polymer dissolution and drug release profiles in a system of Theophylline/cellulose (K15M) demonstrate that API-water mutual diffusivity in the presence of excipient cannot generally be taken as a constant.

  1. [Effect of xuebijing oral effervescent tablet on endotoxin induced fever and disseminated intravascular coagulation rabbit model].

    Science.gov (United States)

    Guo, Shan-Shan; Gao, Ying-Jie; Tian, Xue-Chuan; Jin, Ya-Hong; Liu, Fang-Zhou; Cui, Xiao-Lan

    2013-08-01

    In order to discover the mechanism of Xuebijing oral effervescent tablet (XBJOET) to treat infectious diseases, the effect of XBJOET on endotoxin induced rabbit fever and disseminated intravascular coagulation (DIC) was investigated. Auricle microcirculation in rabbit was detected by laser speckle blood perfusion imager system; coagulation function was measured by coagulation analyzer, fibrinolytic system was quantified by Elisa assay and micro thrombosis in tissues was observed with HE staining under light microscope. The results demonstrated that the body temperature of rabbit decreased significantly at 1-3 h after administration with 4.8, 2.4 and 1.2 g x kg(-1) XBJOET to endotoxin induced DIC rabbit model, the auricle microcirculation blood flow in model group (54.45 +/- 14.53) PU was lower than that in control group (77.18 +/- 12.32) PU. The auricle microcirculation blood flow increased markedly and there was significant difference between model group and 1.2 g x kg(-1) XBJOET group. There was significant difference between model group and control group in the content of PAI1 and FIB. The PAI1 levels in model and control groups were (30.48 +/- 2.46) ng x mL(-1) and (20.93 +/- 3.25) ng x mL(-1), respectively. The FIB levels in model and control group were (3.34 +/- 1.09) g x L(-1) and (4.84 +/- 1.10) g x L(-1), respectively. The content of PAI1 in rabbit plasma decreased notably, there were significant differences between model group and 4.8, 2.4 g x kg(-1) XBJOET groups. On the contrary the content of FIB increased. XBJOET possessed pharmacological activities of curing infectious fever and DIC, the mechanism of which is related to amelioration of microcirculation disturbance, inhibition of fibrinolytic system activation and coagulation and micro thrombosis elimination.

  2. Computational intelligence models to predict porosity of tablets using minimum features.

    Science.gov (United States)

    Khalid, Mohammad Hassan; Kazemi, Pezhman; Perez-Gandarillas, Lucia; Michrafy, Abderrahim; Szlęk, Jakub; Jachowicz, Renata; Mendyk, Aleksander

    2017-01-01

    The effects of different formulations and manufacturing process conditions on the physical properties of a solid dosage form are of importance to the pharmaceutical industry. It is vital to have in-depth understanding of the material properties and governing parameters of its processes in response to different formulations. Understanding the mentioned aspects will allow tighter control of the process, leading to implementation of quality-by-design (QbD) practices. Computational intelligence (CI) offers an opportunity to create empirical models that can be used to describe the system and predict future outcomes in silico. CI models can help explore the behavior of input parameters, unlocking deeper understanding of the system. This research endeavor presents CI models to predict the porosity of tablets created by roll-compacted binary mixtures, which were milled and compacted under systematically varying conditions. CI models were created using tree-based methods, artificial neural networks (ANNs), and symbolic regression trained on an experimental data set and screened using root-mean-square error (RMSE) scores. The experimental data were composed of proportion of microcrystalline cellulose (MCC) (in percentage), granule size fraction (in micrometers), and die compaction force (in kilonewtons) as inputs and porosity as an output. The resulting models show impressive generalization ability, with ANNs (normalized root-mean-square error [NRMSE] =1%) and symbolic regression (NRMSE =4%) as the best-performing methods, also exhibiting reliable predictive behavior when presented with a challenging external validation data set (best achieved symbolic regression: NRMSE =3%). Symbolic regression demonstrates the transition from the black box modeling paradigm to more transparent predictive models. Predictive performance and feature selection behavior of CI models hints at the most important variables within this factor space.

  3. Computational intelligence models to predict porosity of tablets using minimum features

    Science.gov (United States)

    Khalid, Mohammad Hassan; Kazemi, Pezhman; Perez-Gandarillas, Lucia; Michrafy, Abderrahim; Szlęk, Jakub; Jachowicz, Renata; Mendyk, Aleksander

    2017-01-01

    The effects of different formulations and manufacturing process conditions on the physical properties of a solid dosage form are of importance to the pharmaceutical industry. It is vital to have in-depth understanding of the material properties and governing parameters of its processes in response to different formulations. Understanding the mentioned aspects will allow tighter control of the process, leading to implementation of quality-by-design (QbD) practices. Computational intelligence (CI) offers an opportunity to create empirical models that can be used to describe the system and predict future outcomes in silico. CI models can help explore the behavior of input parameters, unlocking deeper understanding of the system. This research endeavor presents CI models to predict the porosity of tablets created by roll-compacted binary mixtures, which were milled and compacted under systematically varying conditions. CI models were created using tree-based methods, artificial neural networks (ANNs), and symbolic regression trained on an experimental data set and screened using root-mean-square error (RMSE) scores. The experimental data were composed of proportion of microcrystalline cellulose (MCC) (in percentage), granule size fraction (in micrometers), and die compaction force (in kilonewtons) as inputs and porosity as an output. The resulting models show impressive generalization ability, with ANNs (normalized root-mean-square error [NRMSE] =1%) and symbolic regression (NRMSE =4%) as the best-performing methods, also exhibiting reliable predictive behavior when presented with a challenging external validation data set (best achieved symbolic regression: NRMSE =3%). Symbolic regression demonstrates the transition from the black box modeling paradigm to more transparent predictive models. Predictive performance and feature selection behavior of CI models hints at the most important variables within this factor space. PMID:28138223

  4. Toward Automated FAÇADE Texture Generation for 3d Photorealistic City Modelling with Smartphones or Tablet Pcs

    Science.gov (United States)

    Wang, S.

    2012-07-01

    An automated model-image fitting algorithm is proposed in this paper for generating façade texture image from pictures taken by smartphones or tablet PCs. The façade texture generation requires tremendous labour work and thus, has been the bottleneck of 3D photo-realistic city modelling. With advanced developments of the micro electro mechanical system (MEMS), camera, global positioning system (GPS), and gyroscope (G-sensors) can all be integrated into a smartphone or a table PC. These sensors bring the possibility of direct-georeferencing for the pictures taken by smartphones or tablet PCs. Since the accuracy of these sensors cannot compared to the surveying instruments, the image position and orientation derived from these sensors are not capable of photogrammetric measurements. This paper adopted the least-squares model-image fitting (LSMIF) algorithm to iteratively improve the image's exterior orientation. The image position from GPS and the image orientation from gyroscope are treated as the initial values. By fitting the projection of the wireframe model to the extracted edge pixels on image, the image exterior orientation elements are solved when the optimal fitting achieved. With the exact exterior orientation elements, the wireframe model of the building can be correctly projected on the image and, therefore, the façade texture image can be extracted from the picture.

  5. Modeling of adhesion in tablet compression - I. atomic force microscopy and molecular simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J. J.; Li, T.; Bateman, S. D.; Erck, R.; Morris, K. R.; Energy Technology; Purdue Univ.; Novartis Pharmaceutical Corp.

    2003-04-01

    Adhesion problems during tablet manufacturing have been observed to be dependent on many formulation and process factors including the run time on the tablet press. Consequently, problems due to sticking may only become apparent towards the end of the development process when a prolonged run on the tablet press is attempted for the first time. It would be beneficial to predict in a relative sense if a formulation or new chemical entity has the potential for adhesion problems early in the development process. It was hypothesized that favorable intermolecular interaction between the drug molecules and the punch face is the first step or criterion in the adhesion process. Therefore, the rank order of adhesion during tablet compression should follow the rank order of these energies of interaction. The adhesion phenomenon was investigated using molecular simulations and contact mode atomic force microscopy (AFM). Three model compounds were chosen from a family of profen compounds. Silicon nitride AFM tips were modified by coating a 20-nm iron layer on the surfaces by sputter coating. Profen flat surfaces were made by melting and recrystallization. The modified AFM probe and each profen surface were immersed in the corresponding profen saturated water during force measurements using AFM. The work of adhesion between iron and ibuprofen, ketoprofen, and flurbiprofen in vacuum were determined to be -184.1, -2469.3, -17.3 mJ {center_dot} m-2, respectively. The rank order of the work of adhesion between iron and profen compounds decreased in the order: ketoprofen > ibuprofen > flurbiprofen. The rank order of interaction between the drug molecules and the iron superlattice as predicted by molecular simulation using Cerius2 is in agreement with the AFM measurements. It has been demonstrated that Atomic Force Microscopy is a powerful tool in studying the adhesion phenomena between organic drug compounds and metal surface. The study has provided insight into the adhesion problems

  6. Simultaneous delivery of Nifedipine and Metoprolol tartarate using sandwiched osmotic pump tablet system.

    Science.gov (United States)

    Kumaravelrajan, R; Narayanan, N; Suba, V; Bhaskar, K

    2010-10-31

    The sandwiched osmotic tablet system that could deliver Nifedipine and Metoprolol tartarate simultaneously for extended period of time was developed in order to reduce the problems associated with multidrug therapy of hypertension. This system composed of a middle push layer and attached drug layers of Nifedipine and Metoprolol. The advantage of the sandwiched osmotic tablet system over the commercialized push-pull osmotic tablet system is its simplicity of preparation, as the surface identification was avoided. Polyethylene oxide 600,000 and 8,000,000 g/mole were used as thickening agent of drug layer and the expandable hydrogel of push layer, respectively. It has been observed that amount of polyethylene oxide (PEO) and KCL of the drug and push layer had profound influence on Nifedipine and Metoprolol release. Further, the release of drugs was optimized by the size of the delivery orifice, level of plasticizer and membrane thickness. The optimal osmotic pump tablet was found to deliver both drugs at a rate of approximately zero order for up to 16 h independent of pH and agitational intensity, but dependent on the osmotic pressure of the release media. The formulations were found to be stable after 3 months of accelerated stability studies. Prediction of steady-state levels showed the plasma concentrations of Nifedipine and Metoprolol to be within the desired range. Further sandwiched system had a good sustained effect in comparison with the conventional product. Hence the prototype design of the system could be applied to other combinations of drugs used for cardiovascular diseases, diabetes, etc.

  7. Statistical modeling methods to analyze the impacts of multiunit process variability on critical quality attributes of Chinese herbal medicine tablets.

    Science.gov (United States)

    Sun, Fei; Xu, Bing; Zhang, Yi; Dai, Shengyun; Yang, Chan; Cui, Xianglong; Shi, Xinyuan; Qiao, Yanjiang

    2016-01-01

    The quality of Chinese herbal medicine tablets suffers from batch-to-batch variability due to a lack of manufacturing process understanding. In this paper, the Panax notoginseng saponins (PNS) immediate release tablet was taken as the research subject. By defining the dissolution of five active pharmaceutical ingredients and the tablet tensile strength as critical quality attributes (CQAs), influences of both the manipulated process parameters introduced by an orthogonal experiment design and the intermediate granules' properties on the CQAs were fully investigated by different chemometric methods, such as the partial least squares, the orthogonal projection to latent structures, and the multiblock partial least squares (MBPLS). By analyzing the loadings plots and variable importance in the projection indexes, the granule particle sizes and the minimal punch tip separation distance in tableting were identified as critical process parameters. Additionally, the MBPLS model suggested that the lubrication time in the final blending was also important in predicting tablet quality attributes. From the calculated block importance in the projection indexes, the tableting unit was confirmed to be the critical process unit of the manufacturing line. The results demonstrated that the combinatorial use of different multivariate modeling methods could help in understanding the complex process relationships as a whole. The output of this study can then be used to define a control strategy to improve the quality of the PNS immediate release tablet.

  8. Serious games for digital tablets as an introduction to 3D modeling and printing

    Directory of Open Access Journals (Sweden)

    José Luis SAORIN

    2015-07-01

    Full Text Available Currently, one of the most direct ways children access to digital technology is through games. This aspect is usually not considered in educational settings in the acquisition of Basic Skills. However, there are international reports assessing the potential of video games as an educational resource. Since 2006, the Horizon Report includes educational video games as a technology impact on teaching, learning and creative expression in education environments. In the 2012 Report, Digital Tablets are considered as one of the technologies most likely to be in widespread use in education in the short term. On the other hand, there are studies linking student interest in careers in science, art and technology to the premature use of 3D modeling tools or 3D printing. In this article, we want to value two applications, Blokify and Pottery, available for digital tablets, which work like games that introduce students to the three-dimensional digital modeling and printing.

  9. A novel system for three-pulse drug release based on "tablets in capsule" device.

    Science.gov (United States)

    Li, Bin; Zhu, JiaBi; Zheng, Chunli; Gong, Wen

    2008-03-20

    The objective of the present study was to obtain programmed drug delivery from a novel system, which contains a water-soluble cap, impermeable capsule body, and two multi-layered tablets. Types of materials for the modulating barrier and its weight can significantly affect the lag time (defined as the time when drug released 8% of the single pulse dosage). We chose sodium alginate and hydroxy-propyl methyl cellulose (HPMC E5) as the candidate modulating barrier material. Through adjusting ratio of sodium alginate and lactose, lag time was controllable between the first two pulsatile release. Linear relationship was observed between the ratio and the lag time. Through adjusting the ratio of HPMC E5/lactose, lag time between the second and the third pulse can be successfully modulated. In further studies, drug release rate of the second pulsatile dose can be improved by adding a separating layer between the third and the modulating barrier layer in the three-layered tablet. To evaluate contribution of bulking agent to drug release rate, lactose, sodium chloride, and effervescent blend were investigated. No superiority was found using sodium chloride and effervescent blend. However, lactose favored it. The results reveal that programmed drug delivery to achieve pulsatile drug release for three times daily can be obtained from these tablets in capsule system by systemic formulation approach.

  10. Use of bicarbonate buffer systems for dissolution characterization of enteric-coated proton pump inhibitor tablets.

    Science.gov (United States)

    Shibata, Hiroko; Yoshida, Hiroyuki; Izutsu, Ken-Ichi; Goda, Yukihiro

    2016-04-01

    The aim of this study was to assess the effects of buffer systems (bicarbonate or phosphate at different concentrations) on the in vitro dissolution profiles of commercially available enteric-coated tablets. In vitro dissolution tests were conducted using an USP apparatus II on 12 enteric-coated omeprazole and rabeprazole tablets, including innovator and generic formulations in phosphate buffers, bicarbonate buffers and a media modified Hanks (mHanks) buffer. Both omeprazole and rabeprazole tablets showed similar dissolution profiles among products in the compendial phosphate buffer system. However, there were large differences between products in dissolution lag time in mHanks buffer and bicarbonate buffers. All formulations showed longer dissolution lag times at lower concentrations of bicarbonate or phosphate buffers. The dissolution rank order of each formulation differed between mHanks buffer and bicarbonate buffers. A rabeprazole formulation coated with a methacrylic acid copolymer showed the shortest lag time in the high concentration bicarbonate buffer, suggesting varied responses depending on the coating layer and buffer components. Use of multiple dissolution media during in vitro testing, including high concentration bicarbonate buffer, would contribute to the efficient design of enteric-coated drug formulations. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

  11. Effects of automated external lubrication on tablet properties and the stability of eprazinone hydrochloride.

    Science.gov (United States)

    Yamamura, Takahiro; Ohta, Tomoaki; Taira, Toshinari; Ogawa, Yutaka; Sakai, Yasuyuki; Moribe, Kunikazu; Yamamoto, Keiji

    2009-03-31

    We investigated the advantages of an external lubrication technique for tableting. A newly developed external lubricating system was applied to tableting in a rotary tablet press using magnesium stearate. The resulting tablets were compared with tablets produced by the conventional internal lubrication method, in which lubricant is blended before tableting. As a model API, we chose eprazinone hydrochloride, because it is easily hydrolyzed by alkaline lubricant. The amount of lubricant required to prevent sticking with external lubrication was only 1/13th of that required with internal lubrication. External lubrication increased tablet crushing strength by 40%, without prolonging tablet disintegration time, and improved the residual ratio of eprazinone hydrochloride in tablets stored under stress conditions for 4 weeks by 10%. The distribution of lubricant on the surface of externally lubricated tablets was observed by scanning electron microscopy after the preparation by focused ion beam milling. The lubricant had formed a layer on the tablet surface. At the central part of the tablet surface, this layer was much thinner than at the edges, and remained extremely thin even when there was excess magnesium stearate. This is the first report to describe the distribution of lubricant on the surface of externally lubricated tablets.

  12. GASTRORETENTIVE DRUG DELIVERY SYSTEM: STOMACH SPECIFIC MUCOADHESIVE TABLET

    OpenAIRE

    Siddhapara Mihir; Tikare Vijay; Ramana MV; Sutariya Bhavesh; Vaghasiya Bhavesh

    2011-01-01

    The current article focuses on the principles of mucoadhesive drug delivery systems based on adhesion to biological surfaces that are covered by mucus. Bioadhesion can be defined as the process by which a natural or a synthetic polymer can adhere to a biological substrate. When the biological substrate is a mucosal layer then the phenomena is known as mucoadhesion. Drug actions can be improved by developing new drug delivery systems, such as the mucoadhesive system. These systems remain in cl...

  13. Nano and Microparticulate Chitosan Based System for Formulation of Carvedilol Rapid Melt Tablet

    Directory of Open Access Journals (Sweden)

    Ravindra Patil

    2015-06-01

    Full Text Available Purpose: In the present study rapid melt tablets (RMT’s of carvedilol were prepared by using ionotropic-gelated chitosan nanoparticles using a spray-drying method. Carvedilol is beta-adrenergic antagonist and its oral bioavailability is about 25-35% because of first pass metabolism. Methods: The spray-dried microparticles were formulated into RMT’s using a wet granulation process. The Formulation and optimization of carvedilol loaded RMTs using nano and microparticulate chitosan based system (NMCS was done by using 32 factorial designs. Results: Drug entrapment efficiency of about 64.9 % (w/w and loading capacity of 14.44% (w/w were achieved for the microparticles, which were ranged from 1 μm to 4 μm in diameter. Results of disintegration tests showed that the formulated RMTs could be completely dissolved within 40 seconds. Dissolution studies suggested that Carvedilol is released more slowly from tablets made using the microencapsulation process compared with tablets containing Carvedilol that is free or in the form of nanoparticles. Conclusion: Results shown that the development of new RMTs designed with crosslinked microparticle might be a rational way to overcome the unwanted taste of conventional RMTs and the side effects related to Carvedilol intrinsic characteristics. The development of Carvedilol NMCS using ludiflash as RMTs could be used as a promising approach for improving the solubility and oral bioavailability of water insoluble drug.

  14. Microspheres and tablet in capsule system: A novel chronotherapeutic system of ketorolac tromethamine for site and time specific delivery

    Science.gov (United States)

    Shahi, Priya; Kumari, Neeraj; Pathak, Kamla

    2015-01-01

    The objective of the present work was to develop a novel delivery system of ketorolac tromethamine (KT) for dual pulse release based on microspheres and tablet in capsule system (MATICS) as a treatment modality for rheumatoid arthritis. The design consisted of an impermeable hard gelatin capsule body, in which a core tablet was (second pulse) placed in the bottom and sealed with a hydrogel plug (HP2). The body was locked with enteric coated cap filled with KT microspheres (first pulse). The microspheres for first pulse were selected by screening the formulations (M1–M6), and M1 with least particle size of 96.38 ± 0.05 μm, highest drug loading of 25.10% ± 0.28% and maximum CDR of 89.32% ± 0.21% was adjudged as the best formulation. The HP2 tablet was selected based on its capability for maintaining a lag period of 6 h. The selection criterion of the second pulse (core tablet: T3) was its disintegration time of 4.02 ± 0.53 min and CDR of 99.10% ± 0.32% in 30 min. All the optimized formulations were assembled in accordance with the proposed design to form pulsatile MATICS and evaluated for in vitro release. MATICS displayed delayed sustained CDR of 80.15% in 8 h from the first pulse (microspheres) after a lag time of 2 h, followed by 97.05% KT release from second pulse (core tablet) in simulated colonic fluid within 10 h. Conclusively, in vitro pulsatile release was a rational combination of delayed sustained and immediate release of KT that has the potential to combat the pain at night and morning stiffness. Incorporation of two pulses in one system offers a reduction in dose frequency and better pain management. PMID:26258058

  15. Statistical modeling methods to analyze the impacts of multiunit process variability on critical quality attributes of Chinese herbal medicine tablets

    Directory of Open Access Journals (Sweden)

    Sun F

    2016-11-01

    Full Text Available Fei Sun,1 Bing Xu,1,2 Yi Zhang,1 Shengyun Dai,1 Chan Yang,1 Xianglong Cui,1 Xinyuan Shi,1,2 Yanjiang Qiao1,2 1Research Center of Traditional Chinese Medicine Information Engineering, School of Chinese Materia Medica, Beijing University of Chinese Medicine, 2Key Laboratory of Manufacture Process Control and Quality Evaluation of Chinese Medicine, Beijing, People’s Republic of China Abstract: The quality of Chinese herbal medicine tablets suffers from batch-to-batch variability due to a lack of manufacturing process understanding. In this paper, the Panax notoginseng saponins (PNS immediate release tablet was taken as the research subject. By defining the dissolution of five active pharmaceutical ingredients and the tablet tensile strength as critical quality attributes (CQAs, influences of both the manipulated process parameters introduced by an orthogonal experiment design and the intermediate granules’ properties on the CQAs were fully investigated by different chemometric methods, such as the partial least squares, the orthogonal projection to latent structures, and the multiblock partial least squares (MBPLS. By analyzing the loadings plots and variable importance in the projection indexes, the granule particle sizes and the minimal punch tip separation distance in tableting were identified as critical process parameters. Additionally, the MBPLS model suggested that the lubrication time in the final blending was also important in predicting tablet quality attributes. From the calculated block importance in the projection indexes, the tableting unit was confirmed to be the critical process unit of the manufacturing line. The results demonstrated that the combinatorial use of different multivariate modeling methods could help in understanding the complex process relationships as a whole. The output of this study can then be used to define a control strategy to improve the quality of the PNS immediate release tablet. Keywords: Panax

  16. An exact model for predicting tablet and blend content uniformity based on the theory of fluctuations in mixtures

    CERN Document Server

    Rane, Sagar S; Rieschl, Sarah

    2012-01-01

    The content uniformity (CU) of blend and tablet formulations is a critical property that needs to be well controlled in order to produce an acceptable pharmaceutical product. Methods that allow the formulations scientist to predict the CU accurately can greatly help in reducing the development efforts. This article presents a new statistical mechanical framework for predicting CU based on first principles at the molecular level. The tablet is modeled as an open system which can be treated as a grand canonical ensemble to calculate fluctuations in the number of granules and thus the CU. Exact analytical solutions to hard sphere mixture systems available in the literature are applied to derive an expression for the CU and elucidate the different factors that impact CU. It is shown that there is a single ratio, {\\lambda}{\\equiv}/; that completely characterizes "granule quality" with respect to impact on CU. Here w and f denote the weight of granule and the fractional (w/w) assay of API in it. This ratio should b...

  17. Computational intelligence models to predict porosity of tablets using minimum features

    Directory of Open Access Journals (Sweden)

    Khalid MH

    2017-01-01

    Full Text Available Mohammad Hassan Khalid,1 Pezhman Kazemi,1 Lucia Perez-Gandarillas,2 Abderrahim Michrafy,2 Jakub Szlęk,1 Renata Jachowicz,1 Aleksander Mendyk1 1Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland; 2Centre National de la Recherche Scientifique, Centre RAPSODEE, Mines Albi, Université de Toulouse, Albi, France Abstract: The effects of different formulations and manufacturing process conditions on the physical properties of a solid dosage form are of importance to the pharmaceutical industry. It is vital to have in-depth understanding of the material properties and governing parameters of its processes in response to different formulations. Understanding the mentioned aspects will allow tighter control of the process, leading to implementation of quality-by-design (QbD practices. Computational intelligence (CI offers an opportunity to create empirical models that can be used to describe the system and predict future outcomes in silico. CI models can help explore the behavior of input parameters, unlocking deeper understanding of the system. This research endeavor presents CI models to predict the porosity of tablets created by roll-compacted binary mixtures, which were milled and compacted under systematically varying conditions. CI models were created using tree-based methods, artificial neural networks (ANNs, and symbolic regression trained on an experimental data set and screened using root-mean-square error (RMSE scores. The experimental data were composed of proportion of microcrystalline cellulose (MCC (in percentage, granule size fraction (in micrometers, and die compaction force (in kilonewtons as inputs and porosity as an output. The resulting models show impressive generalization ability, with ANNs (normalized root-mean-square error [NRMSE] =1% and symbolic regression (NRMSE =4% as the best-performing methods, also exhibiting reliable predictive

  18. Fabrication of extended-release patient-tailored prednisolone tablets via fused deposition modelling (FDM) 3D printing.

    Science.gov (United States)

    Skowyra, Justyna; Pietrzak, Katarzyna; Alhnan, Mohamed A

    2015-02-20

    Rapid and reliable tailoring of the dose of controlled release tablets to suit an individual patient is a major challenge for personalized medicine. The aim of this work was to investigate the feasibility of using a fused deposition modelling (FDM) based 3D printer to fabricate extended release tablet using prednisolone loaded poly(vinyl alcohol) (PVA) filaments and to control its dose. Prednisolone was loaded into a PVA-based (1.75 mm) filament at approximately 1.9% w/w via incubation in a saturated methanolic solution of prednisolone. The physical form of the drug was assessed using differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Dose accuracy and in vitro drug release patterns were assessed using HPLC and pH change flow-through dissolution test. Prednisolone loaded PVA filament demonstrated an ability to be fabricated into regular ellipse-shaped solid tablets using the FDM-based 3D printer. It was possible to control the mass of printed tablet through manipulating the volume of the design (R(2) = 0.9983). On printing tablets with target drug contents of 2, 3, 4, 5, 7.5 and 10mg, a good correlation between target and achieved dose was obtained (R(2) = 0.9904) with a dose accuracy range of 88.7-107%. Thermal analysis and XRPD indicated that the majority of prednisolone existed in amorphous form within the tablets. In vitro drug release from 3D printed tablets was extended up to 24h. FDM based 3D printing is a promising method to produce and control the dose of extended release tablets, providing a highly adjustable, affordable, minimally sized, digitally controlled platform for producing patient-tailored medicines. Copyright © 2015. Published by Elsevier B.V.

  19. The portable P300 dialing system based on tablet and Emotiv Epoc headset.

    Science.gov (United States)

    Tong Jijun; Zhang Peng; Xiao Ran; Ding Lei

    2015-08-01

    A Brain-computer interface (BCI) is a novel communication system that translates brain signals into a control signal. Now with the appearance of the commercial EEG headsets and mobile smart platforms (tablet, smartphone), it is possible to develop the mobile BCI system, which can greatly improve the life quality of patients suffering from motor disease, such as amyotrophic lateral scleroses (ALS), multiple sclerosis, cerebral palsy and head trauma. This study adopted a 14-channel Emotiv EPOC headset and Microsoft surface pro 3 to realize a dialing system, which was represented by 4×3 matrices of alphanumeric characters. The performance of the online portable dialing system based on P300 is satisfying. The average classification accuracy reaches 88.75±10.57% in lab and 73.75±16.94% in metro, while the information transfer rate (ITR) reaches 7.17±1.80 and 5.05±2.17 bits/min respectively. This means the commercial EEG headset and tablet has good prospect in developing real time BCI system in realistic environments.

  20. Adaptation of acoustic model experiments of STM via smartphones and tablets

    Science.gov (United States)

    Thees, Michael; Hochberg, Katrin; Kuhn, Jochen; Aeschlimann, Martin

    2017-10-01

    The importance of Scanning Tunneling Microscopy (STM) in today's research and industry leads to the question of how to include such a key technology in physics education. Manfred Euler has developed an acoustic model experiment to illustrate the fundamental measuring principles based on an analogy between quantum mechanics and acoustics. Based on earlier work we applied mobile devices such as smartphones and tablets instead of using a computer to record and display the experimental data and thus converted Euler's experimental setup into a low-cost experiment that is easy to build and handle by students themselves.

  1. New perspective to develop memantine orally disintegrating tablet formulations: SeDeM expert system.

    Science.gov (United States)

    Gülbağ, Sıla; Yılmaz Usta, Duygu; Gültekin, Hazal E; Oktay, Ayşe N; Demirtaş, Özden; Karaküçük, Alptuğ; Çelebi, Nevin

    2017-07-18

    Nowadays pharmaceutical industries and regulatory authorities suggest new approaches such as Quality by Design principles to reduce experiments of formulation studies, improve product quality, save cost and time. SeDeM Expert System is a predictive approach for the preformulation studies and it provides information about suitability of API for direct compression by evaluating 12 parameters. The system also allows selecting appropriate excipients by determining same parameters to improve compressibility of API. The objective of this study was to develop direct compressed memantine orally disintegrating tablets using SeDeM Expert System. Memantine was found to have poor flow and compressibility properties. Three different direct compressibility and super disintegrating agents (Ludiflash(®), Ludipress(®) and Parteck(®)) were used to improve compressibility of memantine and according to SeDeM diagrams, Parteck(®) was selected for final formulation. Memantine direct compressed tablets showed proper friability, hardness and thickness. The disintegration time of the tables were found below 15 s which was suitable for ODTs. It was found that SeDeM Expert System was easy to use and application of this method provided to develop memantine direct compressed ODT formulation was successful.

  2. [Tablet splitting].

    Science.gov (United States)

    Quinzler, R; Haefeli, W E

    2006-06-01

    The splitting of scored tablets provides many advantages. One benefit is to achieve dose flexibility to account for the huge interindividual differences in dose requirements for instance in paediatric and geriatric patients, which are often not covered by the available strengths in the market. Moreover, large-sized tablets can easier be swallowed if broken before swallowing and medication costs can often be reduced by splitting brands with higher strength. But not all tablets, mostly unscored tablets, are suitable for splitting. Splitting of extended release formulations can result in an overdose by uncontrolled release of the active component and degradation of the compound can occur if an enteric coating is destroyed by the splitting process. Whether tablets are suitable for splitting depends on the properties of the active component (e.g. light sensitivity), the galenics, the shape of the tablet, and the shape of the scoreline. Moreover, not all patients are informed, able, or willing to split tablets and the majority of the elderly population is not capable to break tablets. When split tablets are prescribed it is therefore important to view the shape of the tablet, to assess the patients ability and willingness to break tablets, to properly inform the patient about the appropriate way of splitting, and if necessary to suggest (and instruct) the use of a tablet splitting device.

  3. An effective support system of emergency medical services with tablet computers.

    Science.gov (United States)

    Yamada, Kosuke C; Inoue, Satoshi; Sakamoto, Yuichiro

    2015-02-27

    There were over 5,000,000 ambulance dispatches during 2010 in Japan, and the time for transportation has been increasing, it took over 37 minutes from dispatch to the hospitals. A way to reduce transportation time by ambulance is to shorten the time of searching for an appropriate facility/hospital during the prehospital phase. Although the information system of medical institutions and emergency medical service (EMS) was established in 2003 in Saga Prefecture, Japan, it has not been utilized efficiently. The Saga Prefectural Government renewed the previous system in an effort to make it the real-time support system that can efficiently manage emergency demand and acceptance for the first time in Japan in April 2011. The objective of this study was to evaluate if the new system promotes efficient emergency transportation for critically ill patients and provides valuable epidemiological data. The new system has provided both emergency personnel in the ambulance, or at the scene, and the medical staff in each hospital to be able to share up-to-date information about available hospitals by means of cloud computing. All 55 ambulances in Saga are equipped with tablet computers through third generation/long term evolution networks. When the emergency personnel arrive on the scene and discern the type of patient's illness, they can search for an appropriate facility/hospital with their tablet computer based on the patient's symptoms and available medical specialists. Data were collected prospectively over a three-year period from April 1, 2011 to March 31, 2013. The transportation time by ambulance in Saga was shortened for the first time since the statistics were first kept in 1999; the mean time was 34.3 minutes in 2010 (based on administrative statistics) and 33.9 minutes (95% CI 33.6-34.1) in 2011. The ratio of transportation to the tertiary care facilities in Saga has decreased by 3.12% from the year before, 32.7% in 2010 (regional average) and 29.58% (9085

  4. Design and evaluation of effervescent floating tablets based on hydroxyethyl cellulose and sodium alginate using pentoxifylline as a model drug.

    Science.gov (United States)

    Rahim, Safwan Abdel; Carter, Paul A; Elkordy, Amal Ali

    2015-01-01

    The aim of this work was to design and evaluate effervescent floating gastro-retentive drug delivery matrix tablets with sustained-release behavior using a binary mixture of hydroxyethyl cellulose and sodium alginate. Pentoxifylline was used as a highly water-soluble, short half-life model drug with a high density. The floating capacity, swelling, and drug release behaviors of drug-loaded matrix tablets were evaluated in 0.1 N HCl (pH 1.2) at 37°C±0.5°C. Release data were analyzed by fitting the power law model of Korsmeyer-Peppas. The effect of different formulation variables was investigated, such as wet granulation, sodium bicarbonate gas-forming agent level, and tablet hardness properties. Statistical analysis was applied by paired sample t-test and one-way analysis of variance depending on the type of data to determine significant effect of different parameters. All prepared tablets through wet granulation showed acceptable physicochemical properties and their drug release profiles followed non-Fickian diffusion. They could float on the surface of dissolution medium and sustain drug release over 24 hours. Tablets prepared with 20% w/w sodium bicarbonate at 50-54 N hardness were promising with respect to their floating lag time, floating duration, swelling ability, and sustained drug release profile.

  5. Effect of process variables on the Drucker-Prager cap model and residual stress distribution of tablets estimated by the finite element method.

    Science.gov (United States)

    Hayashi, Yoshihiro; Otoguro, Saori; Miura, Takahiro; Onuki, Yoshinori; Obata, Yasuko; Takayama, Kozo

    2014-01-01

    A multivariate statistical technique was applied to clarify the causal correlation between variables in the manufacturing process and the residual stress distribution of tablets. Theophylline tablets were prepared according to a Box-Behnken design using the wet granulation method. Water amounts (X1), kneading time (X2), lubricant-mixing time (X3), and compression force (X4) were selected as design variables. The Drucker-Prager cap (DPC) model was selected as the method for modeling the mechanical behavior of pharmaceutical powders. Simulation parameters, such as Young's modulus, Poisson rate, internal friction angle, plastic deformation parameters, and initial density of the powder, were measured. Multiple regression analysis demonstrated that the simulation parameters were significantly affected by process variables. The constructed DPC models were fed into the analysis using the finite element method (FEM), and the mechanical behavior of pharmaceutical powders during the tableting process was analyzed using the FEM. The results of this analysis revealed that the residual stress distribution of tablets increased with increasing X4. Moreover, an interaction between X2 and X3 also had an effect on shear and the x-axial residual stress of tablets. Bayesian network analysis revealed causal relationships between the process variables, simulation parameters, residual stress distribution, and pharmaceutical responses of tablets. These results demonstrated the potential of the FEM as a tool to help improve our understanding of the residual stress of tablets and to optimize process variables, which not only affect tablet characteristics, but also are risks of causing tableting problems.

  6. An Innovative Streaming Video System With a Point-of-View Head Camera Transmission of Surgeries to Smartphones and Tablets: An Educational Utility.

    Science.gov (United States)

    Chaves, Rafael Oliveira; de Oliveira, Pedro Armando Valente; Rocha, Luciano Chaves; David, Joacy Pedro Franco; Ferreira, Sanmari Costa; Santos, Alex de Assis Santos Dos; Melo, Rômulo Müller Dos Santos; Yasojima, Edson Yuzur; Brito, Marcus Vinicius Henriques

    2017-10-01

    In order to engage medical students and residents from public health centers to utilize the telemedicine features of surgery on their own smartphones and tablets as an educational tool, an innovative streaming system was developed with the purpose of streaming live footage from open surgeries to smartphones and tablets, allowing the visualization of the surgical field from the surgeon's perspective. The current study aims to describe the results of an evaluation on level 1 of Kirkpatrick's Model for Evaluation of the streaming system usage during gynecological surgeries, based on the perception of medical students and gynecology residents. Consisted of a live video streaming (from the surgeon's point of view) of gynecological surgeries for smartphones and tablets, one for each volunteer. The volunteers were able to connect to the local wireless network, created by the streaming system, through an access password and watch the video transmission on a web browser on their smartphones. Then, they answered a Likert-type questionnaire containing 14 items about the educational applicability of the streaming system, as well as comparing it to watching an in loco procedure. This study is formally approved by the local ethics commission (Certificate No. 53175915.7.0000.5171/2016). Twenty-one volunteers participated, totalizing 294 items answered, in which 94.2% were in agreement with the items affirmative, 4.1% were neutral, and only 1.7% answers corresponded to negative impressions. Cronbach's α was .82, which represents a good reliability level. Spearman's coefficients were highly significant in 4 comparisons and moderately significant in the other 20 comparisons. This study presents a local streaming video system of live surgeries to smartphones and tablets and shows its educational utility, low cost, and simple usage, which offers convenience and satisfactory image resolution, thus being potentially applicable in surgical teaching.

  7. Evaluation of anti-diabetic activity of Glucova Active Tablet on Type I and Type II diabetic model in rats

    Directory of Open Access Journals (Sweden)

    Hardik Soni

    2014-01-01

    Full Text Available Background: Glucova Active Tablet is a proprietary Ayurvedic formulation with ingredients reported for anti-hyperglycemic, anti-hyperlipidemic activity and antioxidant properties. Objective: Evaluation of anti-diabetic activity of Glucova Active Tablet on Type I and Type II diabetic model in rats. Materials and Methods: Experimental Type I diabetes was induced in 24 albino rats with intra-peritoneal injection of streptozotocin (50 mg/kg. Type II diabetes was induced in 18 albino rats by intra-peritoneal injection of streptozotocin (35 mg/kg along with high fat diet. The rats were divided in 5 groups for Type I model and 4 groups for Type II model. Normal control group was kept common for both experimental models. Glucova Active Tablet (108 mg/kg treatment was provided for 28 days twice daily orally. Fasting blood glucose level, serum lipid profile and liver anti-oxidant parameters like superoxide dismutase and reduced glutathione was carried out in both experimental models. Pancreas histopathology was also done. Statistical analysis were done by ′analysis of variance′ test followed by post hoc Tukey′s test, with significant level of P < 0.05.Results and Discussion: Glucova Active Tablet showed significant effect on fasting blood glucose level. It also showed significant alteration in lipid profile and antioxidant parameters. Histopathology study revealed restoration of beta cells in pancreas in Glucova Active Tablet treated group. Conclusion: Finding of this study concludes that Glucova Active Tablet has shown promising anti-diabetic activity in Type I and Type II diabetic rats. It was also found showing good anti-hyperlipidemic activity and anti-oxidant property.

  8. Evaluation of anti-diabetic activity of Glucova Active Tablet on Type I and Type II diabetic model in rats

    Science.gov (United States)

    Soni, Hardik; Patel, Sejal; Patel, Ghanshyam; Paranjape, Archana

    2014-01-01

    Background: Glucova Active Tablet is a proprietary Ayurvedic formulation with ingredients reported for anti-hyperglycemic, anti-hyperlipidemic activity and antioxidant properties. Objective: Evaluation of anti-diabetic activity of Glucova Active Tablet on Type I and Type II diabetic model in rats. Materials and Methods: Experimental Type I diabetes was induced in 24 albino rats with intra-peritoneal injection of streptozotocin (50 mg/kg). Type II diabetes was induced in 18 albino rats by intra-peritoneal injection of streptozotocin (35 mg/kg) along with high fat diet. The rats were divided in 5 groups for Type I model and 4 groups for Type II model. Normal control group was kept common for both experimental models. Glucova Active Tablet (108 mg/kg) treatment was provided for 28 days twice daily orally. Fasting blood glucose level, serum lipid profile and liver anti-oxidant parameters like superoxide dismutase and reduced glutathione was carried out in both experimental models. Pancreas histopathology was also done. Statistical analysis were done by ‘analysis of variance’ test followed by post hoc Tukey's test, with significant level of P < 0.05. Results and Discussion: Glucova Active Tablet showed significant effect on fasting blood glucose level. It also showed significant alteration in lipid profile and antioxidant parameters. Histopathology study revealed restoration of beta cells in pancreas in Glucova Active Tablet treated group. Conclusion: Finding of this study concludes that Glucova Active Tablet has shown promising anti-diabetic activity in Type I and Type II diabetic rats. It was also found showing good anti-hyperlipidemic activity and anti-oxidant property. PMID:24948860

  9. Medically Relevant Assays with a Simple Smartphone and Tablet Based Fluorescence Detection System

    Directory of Open Access Journals (Sweden)

    Piotr Wargocki

    2015-05-01

    Full Text Available Cell phones and smart phones can be reconfigured as biomedical sensor devices but this requires specialized add-ons. In this paper we present a simple cell phone-based portable bioassay platform, which can be used with fluorescent assays in solution. The system consists of a tablet, a polarizer, a smart phone (camera and a box that provides dark readout conditions. The assay in a well plate is placed on the tablet screen acting as an excitation source. A polarizer on top of the well plate separates excitation light from assay fluorescence emission enabling assay readout with a smartphone camera. The assay result is obtained by analysing the intensity of image pixels in an appropriate colour channel. With this device we carried out two assays, for collagenase and trypsin using fluorescein as the detected fluorophore. The results of collagenase assay with the lowest measured concentration of 3.75 µg/mL and 0.938 µg in total in the sample were comparable to those obtained by a microplate reader. The lowest measured amount of trypsin was 930 pg, which is comparable to the low detection limit of 400 pg for this assay obtained in a microplate reader. The device is sensitive enough to be used in point-of-care medical diagnostics of clinically relevant conditions, including arthritis, cystic fibrosis and acute pancreatitis.

  10. Bending energetics of tablet-shaped micelles: a novel approach to rationalize micellar systems.

    Science.gov (United States)

    Bergström, L Magnus

    2007-02-19

    A novel approach to rationalize micellar systems is expounded in which the structural behavior of tablet-shaped micelles is theoretically investigated as a function of the three bending elasticity constants: spontaneous curvature (H0), bending rigidity (k(c)), and saddle-splay constant (k(c)). As a result, experimentally accessible micellar properties, such as aggregation number, length-to-width ratio, and polydispersity, may be related to the different bending elasticity constants. It is demonstrated that discrete micelles or connected cylinders form when H0 > 1/4xi, where xi is the thickness of a surfactant monolayer, whereas various bilayer structures are expected to predominate when H0 bending rigidity is lowered, approaching the critical point at k(c) = 0, whereas monodisperse globular micelles (small length-to-width ratio) are expected to be present at large k(c) values. The spontaneous curvature mainly determines the width of tablet-shaped or ribbonlike micelles, or the radius of disklike micelles, whereas the saddle-splay constant primarily influences the size but not the shape of the micelles.

  11. Oral controlled release drug delivery system and Characterization of oral tablets; A review

    Directory of Open Access Journals (Sweden)

    Muhammad Zaman

    2016-01-01

    Full Text Available Oral route of drug administration is considered as the safest and easiest route of drug administration. Control release drug delivery system is the emerging trend in the pharmaceuticals and the oral route is most suitable for such kind of drug delivery system. Oral route is more convenient for It all age group including both pediatric and geriatrics. There are various systems which are adopted to deliver drug in a controlled manner to different target sites through oral route. It includes diffusion controlled drug delivery systems; dissolution controlled drug delivery systems, osmotically controlled drug delivery systems, ion-exchange controlled drug delivery systems, hydrodynamically balanced systems, multi-Particulate drug delivery systems and microencapsulated drug delivery system. The systems are formulated using different natural, semi-synthetic and synthetic polymers. The purpose of the review is to provide information about the orally controlled drug delivery system, polymers which are used to formulate these systems and characterizations of one of the most convenient dosage form which is the tablets

  12. Modeling methods for mixture-of-mixtures experiments applied to a tablet formulation problem.

    Science.gov (United States)

    Piepel, G F

    1999-01-01

    During the past few years, statistical methods for the experimental design, modeling, and optimization of mixture experiments have been widely applied to drug formulation problems. Different methods are required for mixture-of-mixtures (MoM) experiments in which a formulation is a mixture of two or more "major" components, each of which is a mixture of one or more "minor" components. Two types of MoM experiments are briefly described. A tablet formulation optimization example from a 1997 article in this journal is used to illustrate one type of MoM experiment and corresponding empirical modeling methods. Literature references that discuss other methods for MoM experiments are also provided.

  13. 基于Tablet PC的特大桥结构检查数据采集系统研究%Research on the Huge Bridge Data Collection System Based on Tablet PC

    Institute of Scientific and Technical Information of China (English)

    李悦玲; 王晓晶

    2011-01-01

    Bridge management system has been broadly used in bridge's maintenance and management. The accuracy and efficiency of the on-site data collection were asked higher and higher, but, the data was still collected manually. It is urgent to develop a new bridge (especially for huge bridge) data collection system. This paper used Tablet PC to collect data for huge bridge and developed a new data collection system, which replaced the traditional way of hand-writing records and improved the efficiency and accuracy of data collection. This paper focused on the data collection system based on Tablet PC and the data flow between Tablet PC and huge bridge management system.%随着桥梁养护管理系统越来越广泛的应用到桥梁日常养护和管理当中,对现场采集数据的准确度、效率要求越来越高,目前现场采集数据的方式仍以纸笔记录为主,已无法满足现代桥梁管理的需求,急需研发新的桥梁(尤其是特大桥)数据采集系统.本文将Tablet PC(平板电脑)用于特大桥的数据采集,研发了基于Tablet PC的特大桥结构检查数据采集系统,替代了传统的书写采集方式,提高了特大桥数据采集的效率和准确性.文中重点对Tablet PC数据采集系统、Tablet PC与特大桥养护管理系统间数据传输流程等方面的内容进行研究.

  14. 基于中模孔误差的片重控制数学模型%Mathematical model of tablet weight control based on middle-die hole error

    Institute of Scientific and Technical Information of China (English)

    王行刚; 肖兴明

    2011-01-01

    从分析高速旋转压片机填充工位结构着手,分析影响片重的各种因素,利用数学期望概念,推导出片重的数学公式.研究片重与各影响因素的数学关系,找出决定片重误差的主要因素.提出补偿中模孔深度的相当量概念,各种误差单独出现时,求出各个误差补偿的相当量.各个误差交互出现时,求出中模孔深度误差的数学公式.分析各种误差的性质,利用片重和中模孔深度误差的数学公式,建立高速旋转压片机按照片重误差调节的控制数学模型.在一台40冲GZP高速旋转压片机上,用此控制模型设计片重控制系统,抽样检测表明片重差异度高于国家药品生产管理规范的要求.按照片重误差调节的控制数学模型能够为设计高速旋转压片机片重控制系统提供合理的依据.%Taking the analysis of the filling working procedure on high-speed rotary tablet press as starting point, various influencing factors on tablet weight were analyzed and mathematical formula for tablet weight was derived. Mutual mathematical relation between the tablet weight and the influencing factors was investigated and the main factors which determined tablet weight were found. A conception of compensation equivalent of the depth of middle-die hole was proposed. The compensation equivalent of various errors was found for every individually occurred error. The mathematical formula of the error of middledie hole depth was found for alternately occurred errors. The property of various errors was analyzed. By using the mathematical formulae of tablet weight and depth error of middle-die hole, a mathematical model for controlling high-speed rotary tablet press was established on the basis of error adjustment of tablet weight. The tablet weight control system designed with this control model was installed on a forty-stroke high-speed rotary tablet press GZP. It was shown by sampling detection at the deviation of tablet weight was

  15. Strategic development of a multivariate calibration model for the uniformity testing of tablets by transmission NIR analysis.

    Science.gov (United States)

    Sasakura, D; Nakayama, K; Sakamoto, T; Chikuma, T

    2015-05-01

    The use of transmission near infrared spectroscopy (TNIRS) is of particular interest in the pharmaceutical industry. This is because TNIRS does not require sample preparation and can analyze several tens of tablet samples in an hour. It has the capability to measure all relevant information from a tablet, while still on the production line. However, TNIRS has a narrow spectrum range and overtone vibrations often overlap. To perform content uniformity testing in tablets by TNIRS, various properties in the tableting process need to be analyzed by a multivariate prediction model, such as a Partial Least Square Regression modeling. One issue is that typical approaches require several hundred reference samples to act as the basis of the method rather than a strategically designed method. This means that many batches are needed to prepare the reference samples; this requires time and is not cost effective. Our group investigated the concentration dependence of the calibration model with a strategic design. Consequently, we developed a more effective approach to the TNIRS calibration model than the existing methodology.

  16. A novel spray-dried nanoparticles-in-microparticles system for formulating scopolamine hydrobromide into orally disintegrating tablets

    Directory of Open Access Journals (Sweden)

    Li FQ

    2011-04-01

    Full Text Available Feng-Qian Li1, Cheng Yan2, Juan Bi1, Wei-Lin Lv3, Rui-Rui Ji3, Xu Chen1, Jia-Can Su3, Jin-Hong Hu31Department of Pharmaceutics, Shanghai Eighth People’s Hospital, Shanghai, People’s Republic of China; 2Department of Pharmacy, Bethune International Peace Hospital, Shijiazhuang, People’s Republic of China; 3Changhai Hospital, Second Military Medical University, Shanghai, People’s Republic of ChinaAbstract: Scopolamine hydrobromide (SH-loaded microparticles were prepared from a colloidal fluid containing ionotropic-gelated chitosan nanoparticles using a spray-drying method. The spray-dried microparticles were then formulated into orally disintegrating tablets (ODTs using a wet granulation tablet formation process. A drug entrapment efficiency of about 90% (w/w and loading capacity of 20% (w/w were achieved for the microparticles, which ranged from 2 µm to 8 µm in diameter. Results of disintegration tests showed that the formulated ODTs could be completely dissolved within 45 seconds. Drug dissolution profiles suggested that SH is released more slowly from tablets made using the microencapsulation process compared with tablets containing SH that is free or in the form of nanoparticles. The time it took for 90% of the drug to be released increased significantly from 3 minutes for conventional ODTs to 90 minutes for ODTs with crosslinked microparticles. Compared with ODTs made with noncrosslinked microparticles, it was thus possible to achieve an even lower drug release rate using tablets with appropriate chitosan crosslinking. Results obtained indicate that the development of new ODTs designed with crosslinked microparticles might be a rational way to overcome the unwanted taste of conventional ODTs and the side effects related to SH’s intrinsic characteristics.Keywords: scopolamine hydrobromide, chitosan, nanoparticles-in-microparticles system, spray-drying, orally disintegrating tablets

  17. Gravitational demand on the neck musculature during tablet computer use.

    Science.gov (United States)

    Vasavada, Anita N; Nevins, Derek D; Monda, Steven M; Hughes, Ellis; Lin, David C

    2015-01-01

    Tablet computer use requires substantial head and neck flexion, which is a risk factor for neck pain. The goal of this study was to evaluate the biomechanics of the head-neck system during seated tablet computer use under a variety of conditions. A physiologically relevant variable, gravitational demand (the ratio of gravitational moment due to the weight of the head to maximal muscle moment capacity), was estimated using a musculoskeletal model incorporating subject-specific size and intervertebral postures from radiographs. Gravitational demand in postures adopted during tablet computer use was 3-5 times that of the neutral posture, with the lowest demand when the tablet was in a high propped position. Moreover, the estimated gravitational demand could be correlated to head and neck postural measures (0.48 quantitative data about mechanical requirements on the neck musculature during tablet computer use and are important for developing ergonomics guidelines. Practitioner Summary: Flexed head and neck postures occur during tablet computer use and are implicated in neck pain. The mechanical demand on the neck muscles was estimated to increase 3-5 times during seated tablet computer use versus seated neutral posture, with the lowest demand in a high propped tablet position but few differences in other conditions.

  18. Tableting and tablet properties of alginates: characterisation and potential for Soft Tableting.

    Science.gov (United States)

    Schmid, Wolfgang; Picker-Freyer, Katharina M

    2009-05-01

    The aim of the study was to evaluate the suitability of alginates for Soft Tableting. For this purpose the compaction properties of alginates, varying in molecular weight, guluronic acid/mannuronic acid ratio and salt, were investigated and compared to MCC. Based on the mechanical properties, the suitability of the tested excipients for Soft Tableting was predicted. In order to test the prediction the tested materials were used to tablet enteric coated pellets, which served as a pressure sensitive material. The tableting behaviour was analysed by the 3-D modeling technique. The tablet properties were analysed by determining the elastic recovery and the compactibility. Alginates in general deformed elastically. The compression behaviour depended on the chemical composition of the alginates with sodium alginates being more elastic than potassium alginates. Tablets containing alginates with low guluronic acid content exhibited higher elasticity than tablets with alginates having a low mannuronic acid content. The plasticity of potassium alginates was higher than for sodium alginates. However, the plasticity of all tested alginates was lower than the plasticity of MCC. The compactibility of the tested alginates was sufficient. The proposed prediction, which states that tableting excipients with higher elasticity are more suitable for tableting sensitive materials than plastic excipients, was valid for the tested materials. The elastic alginates inflicted less damage on the pellets than the plastic MCC. Thus, all alginates were more appropriate for tableting pressure sensitive materials than MCC.

  19. The Vindolanda Tablets and the Ancient Economy

    DEFF Research Database (Denmark)

    Evers, Kasper Grønlund

    , a model is outlined which takes into account the different economic behaviours revealed by the tablets and attempts to fit them together into one coherent, economic system, whilst also relating the activities to questions of scale in the ancient economy; moreover, the conclusions drawn in the study......, the aim is to investigate how best to comprehend the economic system attested at Vindolanda and to consider the wider implications for studies of the ancient economy in general. This is accomplished by a three-step approach: first, the nature of the Vindolandan evidence is assessed, and the state...... of research on both studies of the ancient economy and the economy of early Roman Britain is accounted for, so as to highlight the value of the Vindolanda Tablets and lay the ground for the interpretations which follow. Secondly, the economic activities attested by the tablets are analysed in terms of market...

  20. Application of SeDeM Expert system in formulation development of effervescent tablets by direct compression.

    Science.gov (United States)

    Khan, Amjad; Iqbal, Zafar; Rehman, Zahir; Nasir, Fazli; Khan, Abad; Ismail, M; Roohullah; Mohammad, Akhlaq

    2014-11-01

    The SeDeM expert system is a pre formulation tool applied for the prediction of the suitability of a material for direct compression. This innovative tool provides an index of good compressibility of the material indicating its aptitude to be compressed by direct compression. In the study the SeDeM expert system has been applied for the prediction of the behavior of the material to be used in the formulation of effervescent tablets by direct compression. Different formulations were developed on the basis of the results of the SeDeM expert system. Various parameters for the material as per the SeDeM expert system were determined according to their official and reported methods. Powder blend for different formulations was evaluated for their rheological properties while tablets were evaluated for various official and unofficial tests. Suitability of the material for direct compression was successfully predicted using the SeDeM expert system. Domperidone was found unsuitable for direct compression. During formulation all excipients responded as they were predicted as per the SeDeM expert system. Tablets produced using the resultant formulations were having sufficient mechanical strength, free of premature effervescence and were capable to be scaled up for commercial manufacturing.

  1. Kinetic Modelling of Drug Release from Pentoxifylline Matrix Tablets based on Hydrophilic, Lipophilic and Inert Polymers

    Directory of Open Access Journals (Sweden)

    Mircia Eleonora

    2015-12-01

    Full Text Available Pentoxifylline is a xanthine derivative used in the treatment of peripheral vascular disease, which because of its pharmacokinetic and pharmacologic profile is an ideal candidate for the development of extended release formulations. The aim of this study is to present a kinetic analysis of the pentoxifylline release from different extended release tablets formulations, using mechanistic and empirical kinetic models. A number of 28 formulations were prepared and analysed; the analysed formulations differed in the nature of the matrix forming polymers (hydrophilic, lipophilic, inert and in their concentrations. Measurements were conducted in comparison with the reference product Trental 400 mg (Aventis Pharma. The conditions for the dissolution study were according to official regulations of USP 36: apparatus no. 2, dissolution medium water, volume of dissolution medium is 1,000 mL, rotation speed is 50 rpm, spectrophotometric assay at 274 nm. Six mathematical models, five mechanistic (0 orders, 1st-order release, Higuchi, Hopfenberg, Hixson-Crowell and one empirical (Peppas, were fitted to pentoxifylline dissolution profile from each pharmaceutical formulation. The representative model describing the kinetics of pentoxifylline release was the 1st-order release, and its characteristic parameters were calculated and analysed.

  2. System-wide hybrid MPC-PID control of a continuous pharmaceutical tablet manufacturing process via direct compaction.

    Science.gov (United States)

    Singh, Ravendra; Ierapetritou, Marianthi; Ramachandran, Rohit

    2013-11-01

    The next generation of QbD based pharmaceutical products will be manufactured through continuous processing. This will allow the integration of online/inline monitoring tools, coupled with an efficient advanced model-based feedback control systems, to achieve precise control of process variables, so that the predefined product quality can be achieved consistently. The direct compaction process considered in this study is highly interactive and involves time delays for a number of process variables due to sensor placements, process equipment dimensions, and the flow characteristics of the solid material. A simple feedback regulatory control system (e.g., PI(D)) by itself may not be sufficient to achieve the tight process control that is mandated by regulatory authorities. The process presented herein comprises of coupled dynamics involving slow and fast responses, indicating the requirement of a hybrid control scheme such as a combined MPC-PID control scheme. In this manuscript, an efficient system-wide hybrid control strategy for an integrated continuous pharmaceutical tablet manufacturing process via direct compaction has been designed. The designed control system is a hybrid scheme of MPC-PID control. An effective controller parameter tuning strategy involving an ITAE method coupled with an optimization strategy has been used for tuning of both MPC and PID parameters. The designed hybrid control system has been implemented in a first-principles model-based flowsheet that was simulated in gPROMS (Process System Enterprise). Results demonstrate enhanced performance of critical quality attributes (CQAs) under the hybrid control scheme compared to only PID or MPC control schemes, illustrating the potential of a hybrid control scheme in improving pharmaceutical manufacturing operations.

  3. Antacid activity of calcium carbonate and hydrotalcite tablets. Comparison between in vitro evaluation using the "artificial stomach-duodenum" model and in vivo pH-metry in healthy volunteers.

    Science.gov (United States)

    Vatier, J; Ramdani, A; Vitré, M T; Mignon, M

    1994-04-01

    Antacid activity of calcium carbonate (CAM, Rennie) and of hydrotalcite (HYD) containing tablets has been assessed in vitro using computer-controlled "artificial stomach-duodenum" model, including or not a piece of hog gastric mucosa in the gastric reservoir, and simulating the constant flux system or the normal gastroduodenal flux regulation. The data obtained under the latter condition were compared to those obtained in vivo by pH-metry in 12 healthy volunteers, in response to one administration of 2 tablets. The theoretical maximal capacity was similar when 1 tablet of CAM or of HYD was added to the gastric contents, including or not a piece of gastric mucosa, close to 95 H+ mmol. The reduction of acid load penetrating into the duodenum and the duodenal pH were of the same magnitude in response to both antacids. When normal gastroduodenal flux regulation was simulated, a dose-response curve, constructed by 1, 2 or 3 tablets, resulted in the same antacid characteristics in response to both antacids. The maximal gastric and the mean duodenal pH values obtained with CAM were, however, higher than with HYD, corresponding to a greater neutralizing activity developed by CAM than by HYD. The comparison between in vivo administration of two tablets of each antacid and the in vitro model simulating normal gastroduodenal flux regulation in response to the addition of two tablets resulted in similar data. The maximal pH values obtained in in vivo assays were slightly lower than in vitro, depending on the ratio of antacid amount to gastric acid content, well established in in vitro conditions and unknown in in vivo situations.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Tablet Weaving

    Science.gov (United States)

    Kren, Margo

    1976-01-01

    Article described a weaving technique called tablet weaving, an ancient textile process that provides opportunity for making a variety of items, such as guitar straps, belts, and decorative bands. (Author/RK)

  5. Wax-matrix tablet for time-dependent colon-specific delivery system of sophora flavescens Aiton: preparation and in vivo evaluation.

    Science.gov (United States)

    Zou, Meijuan; Wang, Yue; Xu, Caihong; Cheng, Gang; Ren, Jungang; Wu, Gaolei

    2009-02-01

    A wax-matrix time-dependent colon-specific tablet (WM-TDCS) was studied. Wax-matrix tablet core consisting of semi-synthetic glycerides, as a wax polymeric expanding agent, carboxymethyl starch sodium (CMS-Na), and NaCl was prepared, and Sophora flavescens Aiton (ASF, extracts of traditional Chinese medicine) was used as model drug. The wax-matrix ASF tablets core was coated with Eudragit NE 30 D as the inner coating materials and with Opadry OY-P-7171 as the outer coating materials. The in vitro release behaviors of the coated tablets were examined and then in vivo absorption kinetics of the coated tablets in dogs was further investigated. The volume of the tablet core was markedly increased at 37 degrees C because of the expand effect of polymer semi-synthetic glycerides and CMS-Na. The drug release from WM-TDCS was more stable than TDCS in vitro and in vivo. The lag time of ASF release was also controlled by the thickness of the inner coating layer. In vivo evaluation demonstrated that in vivo lag time of absorption was in a good agreement with in vitro lag time of release. ASF wax-matrix tablets coated with Eudragit NE 30 D and Opadry OY-P-7171 using the regular coating technique could be designed to achieve a lag time of 3 h in the small intestinal tract.

  6. Scale-up model describing the impact of lubrication on tablet tensile strength.

    Science.gov (United States)

    Kushner, Joseph; Moore, Francis

    2010-10-31

    Lubrication of 2:1 and 1:1 blends of microcrystalline cellulose and spray-dried lactose or dibasic calcium phosphate (DCP) with 0.33% or 1% magnesium stearate, as model free-flowing pharmaceutical formulations, was performed in rotary drum blenders. Blender process parameters examined in this study included type (Bin, V, and Turbula), volume (0.75-Quart to 200-L), fraction of headspace in the blender after the blend is loaded (30-70%), speed (6-202 rpm), and time (up to 225 min). Based on analysis of the experimental data, the following model for the impact of the lubrication process on tablet tensile strength at 0.85 solid fraction, TS(SF=0.85), was obtained, TS(SF=0.85)=TS(SF=0.85,0) [βexp(-γ×V(1/3)×F(headspace)×r)+(1-β)], where V is blender volume, F(headspace) is the headspace fraction, r is the number of revolutions (i.e. speed × time), TS(SF=0.85,0) is the initial tensile strength of the blend, β is the sensitivity of the blend to lubrication, and γ is the lubrication rate constant of the formulation. This model can be used to maintain tensile strength during scale-up, by ensuring that (V(1/3)F(headspace)r)(1)=(V(1/3)F(headspace)r)(2). The model also suggests that formulations with DCP are less sensitive to lubrication and more slowly lubricated than formulations with spray-dried lactose (i.e. smaller β and γ values).

  7. Coupling 3D printing with hot-melt extrusion to produce controlled-release tablets.

    Science.gov (United States)

    Zhang, Jiaxiang; Feng, Xin; Patil, Hemlata; Tiwari, Roshan V; Repka, Michael A

    2017-03-15

    The main objective of this work was to explore the potential of coupling fused deposition modeling in three-dimensional (3D) printing with hot-melt extrusion (HME) technology to facilitate additive manufacturing, in order to fabricate tablets with enhanced extended release properties. Acetaminophen was used as the model drug and different grades and ratios of polymers were used to formulate tablets. Three-point bending and hardness tests were performed to determine the mechanical properties of the filaments and tablets. 3D-printed tablets, directly compressed mill-extruded tablets, and tablets prepared from a physical mixture were evaluated for drug release rates using a USP-II dissolution apparatus. The surface and cross-sectional morphology of the 3D-printed tablets were assessed by scanning electron microscopy. Differential scanning calorimetry and thermogravimetric analysis were used to characterize the crystal states and thermal properties of materials, respectively. The 3D-printed tablets had smooth surfaces and tight structures; therefore, they showed better extended drug release rates than the directly compressed tablets did. Further, this study clearly demonstrated the feasibility of coupling HME with 3D printing technology, which allows for the formulation of drug delivery systems using different grades and ratios of pharmaceutical polymers. In addition, formulations can be made based on the personal needs of patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Development and evaluation of natural gum-based extended release matrix tablets of two model drugs of different water solubilities by direct compression

    OpenAIRE

    Ofori-Kwakye, Kwabena; Mfoafo, Kwadwo Amanor; Kipo, Samuel Lugrie; Kuntworbe, Noble; Boakye-Gyasi, Mariam EL

    2015-01-01

    The study was aimed at developing extended release matrix tablets of poorly water-soluble diclofenac sodium and highly water-soluble metformin hydrochloride by direct compression using cashew gum, xanthan gum and hydroxypropylmethylcellulose (HPMC) as release retardants. The suitability of light grade cashew gum as a direct compression excipient was studied using the SeDeM Diagram Expert System. Thirteen tablet formulations of diclofenac sodium (∼100 mg) and metformin hydrochloride (∼200 mg) ...

  9. [Process monitoring of dissolution of valsartan and hydrochlorothiazide tablets by fiber-chemical sensor assisted by mathematical separation model of linear equations].

    Science.gov (United States)

    Ding, Hai-Yan; Li, Gai-Ru; Yu, Ying-Ge; Guo, Wei; Zhi, Ling; Li, Xin-Xia

    2014-04-01

    A method for on-line monitoring the dissolution of Valsartan and hydrochlorothiazide tablets assisted by mathematical separation model of linear equations was established. UV spectrums of valsartan and hydrochlorothiazide were overlapping completely at the maximum absorption wavelength respectively. According to the Beer-Lambert principle of absorbance additivity, the absorptivity of Valsartan and hydrochlorothiazide was determined at the maximum absorption wavelength, and the dissolubility of Valsartan and hydrochlorothiazide tablets was detected by fiber-optic dissolution test (FODT) assisted by the mathematical separation model of linear equations and compared with the HPLC method. Results show that two ingredients were real-time determined simultaneously in given medium. There was no significant difference for FODT compared with HPLC (p > 0.05). Due to the dissolution behavior consistency, the preparation process of different batches was stable and with good uniformity. The dissolution curves of valsartan were faster and higher than hydrochlorothiazide. The dissolutions at 30 min of Valsartan and hydrochlorothiazide were concordant with US Pharmacopoeia. It was concluded that fiber-optic dissolution test system assisted by the mathematical separation model of linear equations that can detect the dissolubility of Valsartan and hydrochlorothiazide simultaneously, and get dissolution profiles and overall data, which can directly reflect the dissolution speed at each time. It can provide the basis for establishing standards of the drug. Compared to HPLC method with one-point data, there are obvious advantages to evaluate and analyze quality of sampling drug by FODT.

  10. Preparation and In Vitro/In Vivo Characterization of Porous Sublingual Tablets Containing Ternary Kneaded Solid System of Vinpocetine with β-Cyclodextrin and Hydroxy Acid

    Science.gov (United States)

    Aburahma, Mona H.; El-Laithy, Hanan M.; Hamza, Yassin El-Said

    2010-01-01

    The demand for sublingual tablets has been growing during the previous decades especially for drugs with extensive hepatic first-pass metabolism. Vinpocetine, a widely used neurotropic agent, has low oral bioavailability due to its poor aqueous solubility and marked first-pass metabolism. Accordingly, the aim of this work was to develop tablets for the sublingual delivery of vinpocetine. Initially, the feasibility of improving vinpocetine’s poor aqueous solubility by preparing kneaded solid systems of the drug with β-Cyclodextrin and hydroxy acids (citric acid and tartaric acid) was assessed. The solid system with improved solubility and dissolution properties was incorporated into porous tablets that rapidly disintegrate permitting fast release of vinpocetine into the sublingual cavity. The pores were induced into these tablets by directly compressing the tablets’ excipients with a sublimable material, either camphor or menthol, which was eventually sublimated leaving pores. The obtained results demonstrated that the tablets prepared using camphor attained sufficient mechanical strength for practical use together with rapid disintegration and dissolution. In vivo absorption study performed in rabbits indicated that the sublingual administration of the proposed porous tablets containing vinpocetine solid system with β-Cyclodextrin and tartaric acid could be useful for therapeutic application. PMID:21179352

  11. Development and characterization of fast-dissolving tablet formulations of glyburide based on solid self-microemulsifying systems.

    Science.gov (United States)

    Cirri, Marzia; Roghi, Alessandra; Valleri, Maurizio; Mura, Paola

    2016-07-01

    The aim of this work was to develop effective fast-dissolving tablet formulations of glyburide, endowed with improved dissolution and technological properties, investigating the actual effectiveness of the Solid-Self MicroEmulsifying Drug Delivery System (S-SMEDDS) approach. An initial screening aimed to determine the solubility of the drug in different oils, Surfactants and CoSurfactants allowed the selection of the most suitable components for liquid SMEDDS, whose relative amounts were defined by the construction of pseudo-ternary phase diagrams. The selected liquid SMEDDS formulations (Capyol 90 as oil, Tween 20 as Surfactant and Glycofurol or Transcutol as CoSurfactant) were converted into Solid-SMEDDS, by adsorbing them onto Neusilin (1:1 and 1:0.8w/w S-SMEDDS:carrier), and fully characterized in terms of solid state (DSC and X-ray powder diffraction), morphological (ESEM) and dissolution properties, particle size and reconstitution ability. Finally, the 1:1 S-SMEDDS containing Glycofurol as CoSurfactant, showing the best performance, was selected to prepare two final tablet formulations. The ratio test (t10 min ratio and DE60 ratio) and pair-wise procedures (difference (f1) and similarity (f2) factors) highlighted the similarity of the new developed tablets and the marked difference between their drug dissolution profiles and those of formulations based on the micronized drug. The S-SMEDDS approach allowed to develop fast-dissolving tablets of glyburide, endowed with good technological properties and able to achieve the complete drug dissolution in a time ranging from 10 to 15min, depending on the formulation composition.

  12. Chemometric model for simultaneous spectrophotometric estimation of phenobarbitone and phenytoin sodium in tablets using back-propagation neural network

    Directory of Open Access Journals (Sweden)

    Satyanarayana D

    2006-01-01

    Full Text Available A chemometric model for the simultaneous estimation of phenobarbitone and phenytoin sodium anticonvulsant tablets using the back-propagation neural network calibration has been presented. The use of calibration datasets constructed from the spectral data of pure components is proposed. The calibration sets were designed such that the concentrations were orthogonal and span the possible mixture space fairly evenly. Spectra of phenobarbitone and phenytoin sodium were recorded at several concentrations within their linear range and used to compute the calibration mixture between wavelengths 220 and 260 nm at an interval of 1 nm. The back-propagation neural network model was optimized using three different sets of calibration and monitoring data for the number of hidden sigmoid neurons. The calibration model was thoroughly evaluated at several concentration levels using spectra obtained for 95 synthetic binary mixtures prepared using orthogonal designs. The optimized model showed sufficient robustness even when the calibration sets were constructed from different sets of pure spectra of components. Although the components showed complete spectral overlap, the model could accurately estimate the drugs, with satisfactory precision and accuracy, in tablet dosage with no interference from excipients, as indicated by the recovery study results.

  13. Quantitative Appearance Inspection for Film Coated Tablets.

    Science.gov (United States)

    Yoshino, Hiroyuki; Yamashita, Kazunari; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

    2016-01-01

    The decision criteria for the physical appearance of pharmaceutical products are subjective and qualitative means of evaluation that are based entirely on human interpretation. In this study, we have developed a comprehensive method for the quantitative analysis of the physical appearance of film coated tablets. Three different kinds of film coated tablets with considerable differences in their physical appearances were manufactured as models, and their surface roughness, contact angle, color measurements and physicochemical properties were investigated as potential characteristics for the quantitative analysis of their physical appearance. All of these characteristics were useful for the quantitative evaluation of the physical appearances of the tablets, and could potentially be used to establish decision criteria to assess the quality of tablets. In particular, the analysis of the surface roughness and film coating properties of the tablets by terahertz spectroscopy allowed for an effective evaluation of the tablets' properties. These results indicated the possibility of inspecting the appearance of tablets during the film coating process.

  14. Compound Danshen tablets downregulate amyloid protein precursor mRNA expression in a transgenic cell model of Alzheimer's disease Effects and a comparison with donepezil

    Institute of Scientific and Technical Information of China (English)

    Ren'an Qin; Desheng Zhou; Jiajun Wang; Hua Hu; Yang Yang; Xiaoxuan Yao; Xiaopeng Sun

    2012-01-01

    After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer’s disease. The cell model was treated with donepezil or compound Danshen tablets after culture for 72 hours. Reverse transcription-PCR showed that the mRNA expression of amyloid protein precursor decreased in all groups following culture for 24 hours, and that there was no significant difference in the amount of decrease between donepezil and compound Danshen tablets. Our results suggest that compound Danshen tablets can reduce expression of the mRNA for amyloid protein precursor in a transgenic cell model of Alzheimer’s disease, with similar effects to donepezil.

  15. Design of an expert system for the development and formulation of push-pull osmotic pump tablets containing poorly water-soluble drugs.

    Science.gov (United States)

    Zhang, Zhi-hong; Dong, Hong-ye; Peng, Bo; Liu, Hong-fei; Li, Chun-lei; Liang, Min; Pan, Wei-san

    2011-05-30

    The purpose of this article was to build an expert system for the development and formulation of push-pull osmotic pump tablets (PPOP). Hundreds of PPOP formulations were studied according to different poorly water-soluble drugs and pharmaceutical acceptable excipients. The knowledge base including database and rule base was built based on the reported results of hundreds of PPOP formulations containing different poorly water-soluble drugs and pharmaceutical excipients and the experiences available from other researchers. The prediction model of release behavior was built using back propagation (BP) neural network, which is good at nonlinear mapping and learning function. Formulation design model was established based on the prediction model of release behavior, which was the nucleus of the inference engine. Finally, the expert system program was constructed by VB.NET associating with SQL Server. Expert system is one of the most popular aspects in artificial intelligence. To date there is no expert system available for the formulation of controlled release dosage forms yet. Moreover, osmotic pump technology (OPT) is gradually getting consummate all over the world. It is meaningful to apply expert system on OPT. Famotidine, a water insoluble drug was chosen as the model drug to validate the applicability of the developed expert system. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Preparation of agglomerated crystals for direct tabletting and microencapsulation by the spherical crystallization technique with a continuous system.

    Science.gov (United States)

    Niwa, T; Takeuchi, H; Hino, T; Itoh, A; Kawashima, Y; Kiuchi, K

    1994-04-01

    Adhesive and cohesive properties of chlorpromazine hydrochloride (CP) crystals were modified to improve their powder processing, e.g., direct tabletting and microencapsulation, by agglomeration. Moreover, sustained-released gelling microcapsules of CP were devised to prolong the pharmacological effect. The spherical crystallization technique was applied to prepare agglomerates for direct tabletting and microencapsulation to use them as core materials. The ethanolic solution dissolving CP was poured into a stirred cyclohexane, yielding spherically agglomerated crystals. The resultant agglomerates were free-flowing and easily packable spheres with average diameters of 200 to 1000 microns. The agglomerates reserved the high compressibility of the original powder having a small particle size (14 microns). The compression behavior represented by Heckel's equation suggested that the agglomerates were disintegrated to individual primary crystals at low compression pressures, and then they were closely repacked and plastically deformed at higher pressures. After agglomeration, microencapsulation was continuously performed in the same batch by a phase separation method. Coacervate droplets produced by pouring cyclohexane into a dichloromethane solution, dissolving polyvinyl acetate as a coating polymer, were added to the crystallization system under stirring, to prepare the microcapsules. By filling the microcapsules in gelatin hard capsules or tabletting them, their drug release rates became retarded compared with the physical mixture treated in the same way, having the same formulation as the microcapsules. This phenomenon was due to the gelation of polyvinyl acetate of the microcapsules in the dissolution medium, whose glass transition temperature is very low. This novel sustained-release dosage form is termed "gelled microcapsules."

  17. Developing a mapping tool for tablets

    Science.gov (United States)

    Vaughan, Alan; Collins, Nathan; Krus, Mike

    2014-05-01

    Digital field mapping offers significant benefits when compared with traditional paper mapping techniques in that it provides closer integration with downstream geological modelling and analysis. It also provides the mapper with the ability to rapidly integrate new data with existing databases without the potential degradation caused by repeated manual transcription of numeric, graphical and meta-data. In order to achieve these benefits, a number of PC-based digital mapping tools are available which have been developed for specific communities, eg the BGS•SIGMA project, Midland Valley's FieldMove®, and a range of solutions based on ArcGIS® software, which can be combined with either traditional or digital orientation and data collection tools. However, with the now widespread availability of inexpensive tablets and smart phones, a user led demand for a fully integrated tablet mapping tool has arisen. This poster describes the development of a tablet-based mapping environment specifically designed for geologists. The challenge was to deliver a system that would feel sufficiently close to the flexibility of paper-based geological mapping while being implemented on a consumer communication and entertainment device. The first release of a tablet-based geological mapping system from this project is illustrated and will be shown as implemented on an iPad during the poster session. Midland Valley is pioneering tablet-based mapping and, along with its industrial and academic partners, will be using the application in field based projects throughout this year and will be integrating feedback in further developments of this technology.

  18. Formulation and in vitro evaluation of floating tablets of hydroxypropyl methylcellulose and polyethylene oxide using ranitidine hydrochloride as a model drug.

    Science.gov (United States)

    Gharti, Kp; Thapa, P; Budhathoki, U; Bhargava, A

    2012-10-01

    The present study was carried out with an objective of preparation and in vitro evaluation of floating tablets of hydroxypropyl methyl cellulose (HPMC) and polyethylene oxide (PEO) using ranitidine hydrochloride as a model drug. The floating tablets were based on effervescent approach using sodium bicarbonate a gas generating agent. The tablets were prepared by dry granulation method. The effect of polymers concentration and viscosity grades of HPMC on drug release profile was evaluated. The effect of sodium bicarbonate and stearic acid on drug release profile and floating properties were also investigated. The result of in vitro dissolution study showed that the drug release profile could be sustained by increasing the concentration of HPMC K15MCR and Polyox WSR303. The formulation containing HPMC K15MCR and Polyox WSR303 at the concentration of 13.88% showed 91.2% drug release at the end of 24 hours. Changing the viscosity grade of HPMC from K15MCR to K100MCR had no significant effect on drug release profile. Sodium bicarbonate and stearic acid in combination showed no significant effect on drug release profile. The formulations containing sodium bicarbonate 20 mg per tablet showed desired buoyancy (floating lag time of about 2 minutes and total floating time of >24 hours). The present study shows that polymers like HPMC K15MCR and Polyox WSR303 in combination with sodium bicarbonate as a gas generating agent can be used to develop sustained release floating tablets of ranitidine hydrochloride.

  19. Monitoring and modelling of a continuous from-powder-to-tablet process line

    DEFF Research Database (Denmark)

    Mortier, Séverine T.F.C.; Nopens, Ingmar; De Beer, Thomas

    2014-01-01

    The intention to shift from batch to continuous production processes within the pharmaceutical industry enhances the need to monitor and control the process in-line and real-time to continuously guarantee the end-product quality. Mass and energy balances have been successfully applied to a drying...... process which is part of a continuous from-powder-to-tablet manufacturing line to calculate the residual moisture content of granules leaving the drying unit on the basis of continuously generated data from univariate sensors. Next to monitoring, the application of continuous processes demands also real...

  20. Determination of counterfeit medicines by Raman spectroscopy: Systematic study based on a large set of model tablets.

    Science.gov (United States)

    Neuberger, Sabine; Neusüß, Christian

    2015-08-10

    In the last decade, counterfeit pharmaceutical products have become a widespread issue for public health. Raman spectroscopy which is easy, non-destructive and information-rich is particularly suitable as screening method for fast characterization of chemicals and pharmaceuticals. Combined with chemometric techniques, it provides a powerful tool for the analysis and determination of counterfeit medicines. Here, for the first time, a systematic study of the benefits and limitations of Raman spectroscopy for the analysis of pharmaceutical samples on a large set of model tablets, varying with respect to chemical and physical properties, was performed. To discriminate between the different mixtures, a combination of dispersive Raman spectroscopy performing in backscattering mode and principal component analysis was used. The discrimination between samples with different coatings, a varying amount of active pharmaceutical ingredients and a diversity of excipients were possible. However, it was not possible to distinguish between variations of the press power, mixing quality and granulation. As a showcase, the change in Raman signals of commercial acetylsalicylic acid effervescent tablets due to five different storage conditions was monitored. It was possible to detect early small chemical changes caused by inappropriate storage conditions. These results demonstrate that Raman spectroscopy combined with multivariate data analysis provides a powerful methodology for the fast and easy characterization of genuine and counterfeit medicines. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Modeling of drug release from multi-unit dosage tablets of theophylline

    African Journals Online (AJOL)

    SERVER

    2007-11-19

    Nov 19, 2007 ... dissolution profiles were measured to investigate consistence with the model. ... systems of small discrete individual units such as pellets, granules ..... were determined individually with the Monsanto hardness tester, following ...

  2. Gastrointestinal pH and Transit Time Profiling in Healthy Volunteers Using the IntelliCap System Confirms Ileo-Colonic Release of ColoPulse Tablets.

    Directory of Open Access Journals (Sweden)

    Jacoba M Maurer

    Full Text Available ColoPulse tablets are an innovative development in the field of oral dosage forms characterized by a distal ileum and colon-specific release. Previous studies in humans showed release in the ileo-colonic region, but the relationship between gastrointestinal pH and release was not experimentally proven in vivo. This information will complete the in vivo release-profile of ColoPulse tablets.Release from ColoPulse tablets was studied in 16 healthy volunteers using the dual label isotope strategy. To determine gastrointestinal pH profiles and transit times the IntelliCap system was used. A ColoPulse tablet containing 13C-urea and an uncoated, immediate release tablet containing 15N2-urea were taken simultaneously followed by a standardized breakfast after three hours. Five minutes after intake of the tablets the IntelliCap capsule was swallowed and pH was measured until excretion in the feces. Breath and urine samples were collected for isotope analysis.Full analysis could be performed in 12 subjects. Median bioavailability of 13C -urea was 82% (95% CI 74-94%, range 61-114%. The median lag time (5% release of 13C was 5:42 h (95% CI 5:18-6:18 h, range 2:36-6:36 h, There was no statistically significant difference between lag time based on isotope signal and colon arrival time (CAT based on pH (median 5:42 vs 5:31 h p = 0.903. In all subjects an intestinal pH value of 7.0 was reached before release of 13C from the ColoPulse tablet occurred.From the combined data from the IntelliCap system and the 13C -isotope signal it can be concluded that release from a ColoPulse tablet in vivo is not related to transit times but occurs in the ileo-colonic region after pH 7.0 is reached. This supports our earlier findings and confirms that the ColoPulse system is a promising delivery system for targeting the distal ileum and colon.ISRCTN Registry 18301880.

  3. Analysis of Factor Influencing the Tablet Acceptance for Library Information Services: A Combination of UTAUT and TTF Model

    OpenAIRE

    Sununthar Vongjaturapat; Singha Chaveesuk; Nopporn Chotikakamthorn; Sakesan Tongkhambanchong

    2015-01-01

    Increasingly, powerful mobile technology, like the tablet, empowers learners to seek information in mobile learning scenarios virtually anywhere and anytime. It is important for the academic library to look at how students use their tablets for library information seeking tasks to fully understand the nature of the patron's task and the need for the tablet. This study investigates the function of mobile technology based on the information seeking task, with particular reference to the appropr...

  4. Tablet Use within Medicine

    Science.gov (United States)

    Hogue, Rebecca J.

    2013-01-01

    This paper discusses the scholarly literature related to tablet computer use in medicine. Forty-four research-based articles were examined for emerging categories and themes. The most studied uses for tablet computers include: patients using tablets to complete diagnostic survey instruments, medical professionals using tablet computers to view…

  5. Deposition of a model substance, Tc E-HIDA, in the oral cavity after administration of lozenges, chewing gum and sublingual tablets

    DEFF Research Database (Denmark)

    Christrup, Lona Louring; Davis, S.S.; Melia, C.D.

    1990-01-01

    The deposition and clearance of a model substance, Tc E-HIDA, in the oral cavity/upper oesophagus and in the stomach after administration of lozenges, chewing gum and sublingual tablets has been followed by gamma scintigraphy in a group of healthy male volunteers. Following administration...

  6. Lubrication in tablet formulations.

    Science.gov (United States)

    Wang, Jennifer; Wen, Hong; Desai, Divyakant

    2010-05-01

    Theoretical aspects and practical considerations of lubrication in tablet compression are reviewed in this paper. Properties of the materials that are often used as lubricants, such as magnesium stearate, in tablet dosage form are summarized. The manufacturing process factors that may affect tablet lubrication are discussed. As important as the lubricants in tablet formulations are, their presence can cause some changes to the tablet physical and chemical properties. Furthermore, a detailed review is provided on the methodologies used to characterize lubrication process during tablet compression with relevant process analytical technologies. Finally, the Quality-by-Design considerations for tablet formulation and process development in terms of lubrication are discussed.

  7. NOOK tablet for dummies

    CERN Document Server

    Sandler, Corey

    2012-01-01

    The fun is just a tap away with the nifty NOOK Tablet! It's an e-reader, it's a tablet, and it's hot! The NOOK Tablet offers all the advantages of an Android-based tablet, and this small-trim book is packed with information about how to use it. Learn to set up your NOOK Tablet, navigate the touchscreen, download and read e-books, access the Internet, use all the cool Android apps that are included, and much more. Find out how to create your own e-books, share books with others, listen to music or watch streaming video on your NOOK Tablet, personalize your tablet, add accessories, and

  8. Transforming the Classroom With Tablet Technology.

    Science.gov (United States)

    Sargent, Lana; Miles, Elizabeth

    Identifying the most effective models for integrating new technology into the classroom and understanding its effects on educational outcomes are essential for nurse educators. This article describes an educational intervention with tablet technology (iPads) using an innovative case-based learning model in a nursing program. Students reported positive learning outcomes when using the tablet technology for learning course content.

  9. Formation of chocolate-tablet boudins: Results from scaled analogue models

    Science.gov (United States)

    Zulauf, J.; Zulauf, G.; Göttlich, J.; Peinl, M.

    2014-11-01

    We used power-law viscous plasticine as a rock analogue to simulate chocolate tablet boudinage of rocks undergoing dislocation creep. A competent plasticine layer, oriented perpendicular to the main shortening direction, Z, underwent two phases of plane strain in a weaker plasticine matrix, with the principal stretching axis, X, and the axis of no-change, Y, replacing each other from the first to the second phase. In each phase of plane strain, boudinage was controlled by an initial phase of viscous necking followed by extension fracture along the neck domain. Increase in the magnitude of finite strain (e) and decrease in layer thickness (Hi) result in a decrease in the boudin width (Wa) and an increase in the number of boudins (N). Given the viscosity ratio between layer and matrix (m) is higher than ca. 5, the number of boudins decreases and the boudin width increases with increasing values of m. An unexpected result of the present study is that in each experiment, the number of boudins was significantly higher during the second phase of plane strain. This difference should be related to additional drag of the matrix plasticine on the stiff layer in the neck domains formed during the first phase of boudinage. The aspect ratio of the second generation of boudins (Wd = Wa/Hi) is compatible with aspect ratios of natural boudins and with aspect ratios calculated using analytical solutions.

  10. The Clinical Assessment and Remote Administration Tablet

    Directory of Open Access Journals (Sweden)

    Jessica A Turner

    2011-12-01

    Full Text Available Electronic data capture of case report forms (CRFs, demographic, neuropsychiatric, or clinical assessments, can vary from scanning hand-written forms into databases to fully electronic systems. Web-based forms can be extremely useful for self-assessment; however, in the case of neuropsychiatric assessments, self-assessment is often not an option. The clinician often must be the person either summarizing or making their best judgment about the subject’s response in order to complete an assessment, and having the clinician turn away to type into a web browser may be disruptive to the flow of the interview. The Mind Research Network (MRN has developed a prototype for a software tool for the real-time acquisition and validation of clinical assessments in remote environments. We have developed the Clinical Assessment and Remote Administration Tablet (CARAT on a Microsoft Windows PC tablet system, which has been adapted to interact with various data models already in use in several large-scale databases of neuroimaging studies in clinical populations. The tablet has been used successfully to collect and administer clinical assessments in several large-scale studies, so that the correct clinical measures are integrated with the correct imaging and other data. It has proven to be incredibly valuable in confirming that data collection across multiple research groups is performed similarly, quickly, and with accountability for incomplete datasets. We present the overall architecture and an evaluation of its use.

  11. Evaluation of the drug solubility and rush ageing on drug release performance of various model drugs from the modified release polyethylene oxide matrix tablets.

    Science.gov (United States)

    Shojaee, Saeed; Nokhodchi, Ali; Maniruzzaman, Mohammed

    2017-02-01

    Hydrophilic matrix systems are currently some of the most widely used drug delivery systems for controlled-release oral dosage forms. Amongst a variety of polymers, polyethylene oxide (PEO) is considered an important material used in pharmaceutical formulations. As PEO is sensitive to thermal oxidation, it is susceptible to free radical oxidative attack. The aim of this study was to investigate the stability of PEO based formulations containing different model drugs with different water solubility, namely propranolol HCl, theophylline and zonisamide. Both polyox matrices 750 and 303 grade were used as model carriers for the manufacture of tablets stored at 40 °C. The results of the present study suggest that the drug release from the matrix was affected by the length of storage conditions, solubility of drugs and the molecular weight of the polymers. Generally, increased drug release rates were prevalent in soluble drug formulations (propranolol) when stored at the elevated temperature (40 °C). In contrast, it was not observed with semi soluble (theophylline) and poorly soluble (zonisamide) drugs especially when formulated with PEO 303 polymer. This indicates that the main parameters controlling the drug release from fresh polyox matrices are the solubility of the drug in the dissolution medium and the molecular weight of the polymer. DSC traces indicated that that there was a big difference in the enthalpy and melting points of fresh and aged PEO samples containing propranolol, whereas the melting point of the aged polyox samples containing theophylline and zonisamide was unaffected. Graphical abstract ᅟ.

  12. Toward predicting tensile strength of pharmaceutical tablets by ultrasound measurement in continuous manufacturing.

    Science.gov (United States)

    Razavi, Sonia M; Callegari, Gerardo; Drazer, German; Cuitiño, Alberto M

    2016-06-30

    An ultrasound measurement system was employed as a non-destructive method to evaluate its reliability in predicting the tensile strength of tablets and investigate the benefits of incorporating it in a continuous line, manufacturing solid dosage forms. Tablets containing lactose, acetaminophen, and magnesium stearate were manufactured continuously and in batches. The effect of two processing parameters, compaction force and level of shear strain were examined. Young's modulus and tensile strength of tablets were obtained by ultrasound and diametrical mechanical testing, respectively. It was found that as the blend was exposed to increasing levels of shear strain, the speed of sound in the tablets decreased and the tablets became both softer and mechanically weaker. Moreover, the results indicate that two separate tablet material properties (e.g., relative density and Young's modulus) are necessary in order to predict tensile strength. A strategy for hardness prediction is proposed that uses the existing models for Young's modulus and tensile strength of porous materials. Ultrasound testing was found to be very sensitive in differentiating tablets with similar formulation but produced under different processing conditions (e.g., different level of shear strain), thus, providing a fast, and non-destructive method for hardness prediction that could be incorporated to a continuous manufacturing process.

  13. Enteric coating of ibuprofen tablets (200 mg using an aqueous dispersion system

    Directory of Open Access Journals (Sweden)

    Rabia Bushra

    2010-03-01

    Full Text Available Ibuprofen is a propionic acid derivative that belongs to the class NSAIDs. Major adverse reactions associated with Ibuprofen are related to GIT and include peptic and mucosal ulcers, dyspepsia, severe gastric pain and bleeding, that results in excessive treatment failure. The goal of this study was to develop enteric coated ibuprofen tablets in order to avoid gastric mucosal irritation, diffusion of drug across mucosal lining and to let active ingredient be absorbed easily in small intestine. The formulation was developed and manufactured through the direct compression process, the simplest, easiest and most economical method of manufacturing. Enteric coating was done using an Opadry white subcoating and an aqueous coating dispersion of Acryl-Eze. Enteric coated formulation was subjected to disintegration and dissolution tests by placing in 0.1 M hydrochloric acid for 2 h and then 1 h in phosphate buffer with a pH of 6.8. About 0.04% of drug was released in the acidic phase and 99.05% in the basic medium. These results reflect that ibuprofen can be successfully enteric coated in order to prevent its release in the stomach and facilitate rapid release of the drug in the duodenum, due to the presence of superdisintegrant. Formulating this enteric coated tablets could increase patient compliance by decreasing adverse drug reactions (ADR S associated with Ibuprofen therapy.Ibuprofeno é um derivado do ácido propiônico, que pertence à classe dos fármacos não-esteróides (AINES. As principais reações adversas associadas com o ibuprofeno se referem àquelas do trato gastrintestinal (TGI, como úlceras pépticas e da mucosa, dispepsia, dor gástrica grave e sangramento, que resultam em muitas falhas de tratamento. O objetivo do estudo foi desenvolver comprimidos revestidos de ibuprofeno que impeçam a irritação da mucosa gástrica, difusão do fármaco através da mucosa e permitam, facilmente, a absorção do princípio ativo do intestino

  14. [Development of glipizide push-pull osmotic pump controlled release tablets by using expert system and artificial neural network].

    Science.gov (United States)

    Zhang, Zhi-Hong; Wang, Yue; Wu, Wen-Fang; Zhao, Xi; Sun, Xiao-Cui; Wang, Huan-Qing

    2012-12-01

    The purpose of this study is to develop glipizide push-pull osmotic pump (PPOP) tablets by using a formulation design expert system and an artificial neural network (ANN). Firstly, the expert system for the formulation design of osmotic pump of poor water-soluble drug was employed to design the formulation of glipizide PPOP, taking the dissolution test results of Glucotrol XL as the goal. Then glipizide PPOP was prepared according to the designed formulations and the in vitro dissolution was carried out. And in vivo evaluation was carried out between the samples which were similar to Glucotrol XL and the Glucotrol XL in Beagle dogs. The range of the factors of formulation and procedure, which could influence the drug release, was optimized using artificial neural network. Finally, the design space was found. It was found that the target formulation which was similar to Glucotrol XL in dissolution test could be obtained in a short period by using the expert system. The samples which were similar to Glucotrol XL were bio-equivalent to the Glucotrol XL in Beagle dogs. The design space of the key parameter coating weight gain was 9.5%-12.0%. It could be concluded that a well controlled product of glipizide PPOP was developed since the dissolution test standard of our product was more strict than that of Glucotrol XL.

  15. Predicting absorption and pharmacokinetic profile of carbamazepine from controlled-release tablet formulation in humans using rabbit model

    Directory of Open Access Journals (Sweden)

    Homšek Irena

    2011-01-01

    Full Text Available Controlled-release (CR pharmaceutical formulations offer several advantages over the conventional, immediate release dosage forms of the same drug, including reduced dosing frequency, decreased incidence and/or intensity of adverse effects, greater selectivity of pharmacological activity, reduced drug plasma fluctuation, and better compliance. After a drug product has been registered, and is already on market, minor changes in formulation might be needed. At the same time, the product has to remain effective and safe for patients that could be confirmed via plasma drug concentrations and pharmacokinetic characteristics. It is challenging to predict human absorption and pharmacokinetic characteristics of a drug based on the in vitro dissolution test and the animal pharmacokinetic data. Therefore, the objective of this study was to establish correlation of the pharmacokinetic parameters of carbamazepine (CBZ CR tablet formulation between the rabbit and the human model, and to establish in vitro in vivo correlation (IVIVC based on the predicted fractions of absorbed CBZ. Although differences in mean plasma concentration profiles were notified, the data concerning the predicted fraction of drug absorbed were almost superimposable. Accordingly, it can be concluded that rabbits may be representative as an in vivo model for predicting the pharmacokinetics of the CR formulation of CBZ in humans.

  16. In Vitro Dissolution and In Vivo Bioavailability of Six Brands of Ciprofloxacin Tablets Administered in Rabbits and Their Pharmacokinetic Modeling

    Directory of Open Access Journals (Sweden)

    Sahar Fahmy

    2014-01-01

    Full Text Available This study was undertaken to assess the in vitro dissolution and in vivo bioavailability of six brands of ciprofloxacin oral tablets available in the UAE market using rabbits. The in vitro dissolution profiles of the six ciprofloxacin products were determined using the USP dissolution paddle method. Pharmacokinetic modeling using compartmental and noncompartmental analysis was done to determine the pharmacokinetic parameters of ciprofloxacin after single-dose oral administration. In vitro release study revealed that the amount of ciprofloxacin released in 20 minutes was not less than 80% of the labeled amount which is in accordance with the pharmacopoeial requirements. All tested products are considered to be very rapid dissolving except for formulae A and D. Ciprofloxacin plasma concentration in rabbits was best fitted to a two-compartment open model. The lowest bioavailability was determined to be for product A (93.24% while the highest bioavailability was determined to be for product E (108.01%. Postmarketing surveillance is very crucial to ensure product quality and eliminating substandard products to be distributed and, consequently, ensure better patient clinical outcome. The tested ciprofloxacin generic products distributed in the UAE market were proven to be of good quality and could be used interchangeably with the branded ciprofloxacin product.

  17. ORALLY DISINTEGRATING TABLETS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Mudgal Vinod Kumar

    2011-04-01

    Full Text Available Orally disintegrating tablets (ODTs are gaining prominence as new drug delivery systems and emerged as one of the popular and widely accepted dosage forms, especially for the pediatric and geriatric patients. To obviate the problem of dysphagia and to improve patient compliance, ODTs have gained considerable attention as preferred alternatives to conventional tablet and capsule formulations. Various scientific techniques including freeze drying, moulding, spray drying, sublimation, direct compression, cotton candy process, mass extrusion, melt granulation etc. have been employed for the development of ODTs. These techniques render the disintegration of tablet rapidly and dissolve in mouth without chewing or additional water intake. The current article is focused on ideal characteristics, significant features, patented technologies, formulation aspects including the use of superdisintegrants. Various marketed preparations along with numerous scientific advancements made so far in this avenue have also been discussed.

  18. Experimental study of tensile strength of pharmaceutical tablets: effect of the diluent nature and compression pressure

    Science.gov (United States)

    Juban, Audrey; Briançon, Stéphanie; Puel, François; Hoc, Thierry; Nouguier-Lehon, Cécile

    2017-06-01

    In the pharmaceutical field, tablets are the most common dosage form for oral administration in the world. Among different manufacturing processes, direct compression is widely used because of its economics interest and it is a process which avoids the steps of wet granulation and drying processes. Tablets are composed of at least two ingredients: an active pharmaceutical ingredient (API) which is mixed with a diluent. The nature of the powders and the processing conditions are crucial for the properties of the blend and, consequently, strongly influence the mechanical characteristics of tablets. Moreover, tablets have to present a suitable mechanical strength to avoid crumbling or breaking when handling, while ensuring an appropriate disintegration after administration. Accordingly, this mechanical property is an essential parameter to consider. Experimental results showed that proportion of the diluent, fragmentary (DCPA) or plastic (MCC), had a large influence on the tensile strength evolution with API content as well as the compression load applied during tableting process. From these results a model was developed in order to predict the tensile strength of binary tablets by knowing the compression pressure. The validity of this model was demonstrated for the two studied systems and a comparison was made with two existing models.

  19. Experimental study of tensile strength of pharmaceutical tablets: effect of the diluent nature and compression pressure

    Directory of Open Access Journals (Sweden)

    Juban Audrey

    2017-01-01

    Full Text Available In the pharmaceutical field, tablets are the most common dosage form for oral administration in the world. Among different manufacturing processes, direct compression is widely used because of its economics interest and it is a process which avoids the steps of wet granulation and drying processes. Tablets are composed of at least two ingredients: an active pharmaceutical ingredient (API which is mixed with a diluent. The nature of the powders and the processing conditions are crucial for the properties of the blend and, consequently, strongly influence the mechanical characteristics of tablets. Moreover, tablets have to present a suitable mechanical strength to avoid crumbling or breaking when handling, while ensuring an appropriate disintegration after administration. Accordingly, this mechanical property is an essential parameter to consider. Experimental results showed that proportion of the diluent, fragmentary (DCPA or plastic (MCC, had a large influence on the tensile strength evolution with API content as well as the compression load applied during tableting process. From these results a model was developed in order to predict the tensile strength of binary tablets by knowing the compression pressure. The validity of this model was demonstrated for the two studied systems and a comparison was made with two existing models.

  20. Developing and validating a tablet version of an illness explanatory model interview for a public health survey in Pune, India.

    Directory of Open Access Journals (Sweden)

    Joseph G Giduthuri

    Full Text Available BACKGROUND: Mobile electronic devices are replacing paper-based instruments and questionnaires for epidemiological and public health research. The elimination of a data-entry step after an interview is a notable advantage over paper, saving investigator time, decreasing the time lags in managing and analyzing data, and potentially improving the data quality by removing the error-prone data-entry step. Research has not yet provided adequate evidence, however, to substantiate the claim of fewer errors for computerized interviews. METHODOLOGY: We developed an Android-based illness explanatory interview for influenza vaccine acceptance and tested the instrument in a field study in Pune, India, for feasibility and acceptability. Error rates for tablet and paper were compared with reference to the voice recording of the interview as gold standard to assess discrepancies. We also examined the preference of interviewers for the classical paper-based or the electronic version of the interview and compared the costs of research with both data collection devices. RESULTS: In 95 interviews with household respondents, total error rates with paper and tablet devices were nearly the same (2.01% and 1.99% respectively. Most interviewers indicated no preference for a particular device; but those with a preference opted for tablets. The initial investment in tablet-based interviews was higher compared to paper, while the recurring costs per interview were lower with the use of tablets. CONCLUSION: An Android-based tablet version of a complex interview was developed and successfully validated. Advantages were not compromised by increased errors, and field research assistants with a preference preferred the Android device. Use of tablets may be more costly than paper for small samples and less costly for large studies.

  1. Design and development of bilayer tablet for immediate and extended release of acarbose and metformin HCl

    Directory of Open Access Journals (Sweden)

    Meenakshi Joshi

    2014-01-01

    Full Text Available The present investigation studied a novel Bilayer tablet having extended release (ER system of metformin HCl (M.HCl with Eudragit RS 100 and RL 100 and immediate release (IR system of Acarbose with PVP K30 and PEG 6000 in different ratios using solvent evaporation technique. Solid dispersions (SDs were characterized by Fourier Transform-Infra Red spectroscopy, Diffrential Scanning Calorimetry, X-Ray Diffractometry and Scanning Electron Microscopy. Selected SD system was subjected to Bilayer tablet preparation by direct compression. Compressed tablets were evaluated for physical parameters, drug release and stability. SEM studies suggested the homogenous dispersion of the drug in polymers. FT-IR studies confirmed the formation of hydrogen bonding between the drug and polymer. XRD and DSC suggested the amorphous nature of the drug in SDs. All tablet formulations showed compliance with pharmacopoeial standards. In-vitro dissolution kinetics followed the Higuchi model via a non-fickian diffusion controlled release mechanism after the initial burst release. Stability studies conducted for optimized formulation did not show any change in the physical properties, drug content and drug release. Bilayer tablets showed an IR effect to provide the loading dose of the drug, followed by ER effect for 12 h, indicating a promising potential of the M.HCl and Acarbose Bilayer tablet as an alternative to the conventional dosage form.

  2. Accuracy of tablet splitting.

    Science.gov (United States)

    McDevitt, J T; Gurst, A H; Chen, Y

    1998-01-01

    We attempted to determine the accuracy of manually splitting hydrochlorothiazide tablets. Ninety-four healthy volunteers each split ten 25-mg hydrochlorothiazide tablets, which were then weighed using an analytical balance. Demographics, grip and pinch strength, digit circumference, and tablet-splitting experience were documented. Subjects were also surveyed regarding their willingness to pay a premium for commercially available, lower-dose tablets. Of 1752 manually split tablet portions, 41.3% deviated from ideal weight by more than 10% and 12.4% deviated by more than 20%. Gender, age, education, and tablet-splitting experience were not predictive of variability. Most subjects (96.8%) stated a preference for commercially produced, lower-dose tablets, and 77.2% were willing to pay more for them. For drugs with steep dose-response curves or narrow therapeutic windows, the differences we recorded could be clinically relevant.

  3. Formulation and evaluation of floating tablets of liquorice extract

    Directory of Open Access Journals (Sweden)

    H N Aswatha Ram

    2010-01-01

    Full Text Available Background: Floating tablets prolong the gastric residence time of drugs, improve bioavailability, and facilitate local drug delivery to the stomach. With this objective, floating tablets containing aqueous extract of liquorice as drug was prepared for the treatment of Helicobacter pylori and gastric ulcers. Methods: The aqueous extract of liquorice was standardized by HPTLC. Tablets containing HPMC K100M (hydrophilic polymer, liquorice extract, sodium bicarbonate (gas generating agent, talc, and magnesium stearate were prepared using direct compression method. The formulations were evaluated for physical parameters like diameter, thickness, hardness, friability, uniformity of weight, drug content, buoyancy time, dissolution, and drug release mechanism. The formulations were optimized on the basis of buoyancy time and in vitro drug release. Results: The diameter of all formulations was in the range 11.166-11.933 mm; thickness was in the range 4.02-4.086 mm. The hardness ranged from 3.1 to 3.5 kg/cm 2 . All formulations passed the USP requirements for friability and uniformity of weight. The buoyancy time of all tablet formulations was less than 5 min and tablet remained in floating condition throughout the study. All the tablet formulations followed zero-order kinetics and Korsemeyer-Peppas model in drug release. Conclusion: The optimized formulation was found to be F6 which released 98.3% of drug in 8 h in vitro, while the buoyancy time was 3.5 min. Formulations containing psyllium husk, sodium bicarbonate and HPMC K100M in combination can be a promising for gastroretentive drug delivery systems.

  4. A novel spray-dried nanoparticles-in-microparticles system for formulating scopolamine hydrobromide into orally disintegrating tablets.

    Science.gov (United States)

    Li, Feng-Qian; Yan, Cheng; Bi, Juan; Lv, Wei-Lin; Ji, Rui-Rui; Chen, Xu; Su, Jia-Can; Hu, Jin-Hong

    2011-01-01

    Scopolamine hydrobromide (SH)-loaded microparticles were prepared from a colloidal fluid containing ionotropic-gelated chitosan nanoparticles using a spray-drying method. The spray-dried microparticles were then formulated into orally disintegrating tablets (ODTs) using a wet granulation tablet formation process. A drug entrapment efficiency of about 90% (w/w) and loading capacity of 20% (w/w) were achieved for the microparticles, which ranged from 2 μm to 8 μm in diameter. Results of disintegration tests showed that the formulated ODTs could be completely dissolved within 45 seconds. Drug dissolution profiles suggested that SH is released more slowly from tablets made using the microencapsulation process compared with tablets containing SH that is free or in the form of nanoparticles. The time it took for 90% of the drug to be released increased significantly from 3 minutes for conventional ODTs to 90 minutes for ODTs with crosslinked microparticles. Compared with ODTs made with noncrosslinked microparticles, it was thus possible to achieve an even lower drug release rate using tablets with appropriate chitosan crosslinking. Results obtained indicate that the development of new ODTs designed with crosslinked microparticles might be a rational way to overcome the unwanted taste of conventional ODTs and the side effects related to SH's intrinsic characteristics.

  5. The combined effects of capsaicin, green tea extract and chicken essence tablets on human autonomic nervous system activity.

    Science.gov (United States)

    Shin, Ki Ok; Moritani, Toshio

    2007-04-01

    The purpose of this study was to investigate whether combined capsaicin, green tea, and chicken essence tablets (CCGC) enhance human autonomic nervous activities (ANS) associated with thermogenic sympathetic activity without any adverse effect on the cardiac depolarization-repolarization period. Six healthy males (25.2 +/-1.7 y) volunteered for this experiment. Autonomic nervous activities were examined 5-min at rest per 30-min for total 1.5 h after consuming chicken or CCGC or placebo tablets at random on separate days. Using heart rate variability power spectral analysis, we assessed human autonomic nervous activities. In comparison to chicken essence or placebo tablets, it was observed that the consumption of CCGC significantly increased human autonomic nervous activities [Total power representing over-all ANS activity; CCGC trial 160.2 (50.0) vs. placebo 92.8 (53.3)%, p chicken 130.5 (52.9)%, p chicken essence or placebo tablets. Therefore, these results suggest that combined capsaicin, green tea, and chicken essence tablets may be a beneficial food ingredient improving human autonomic nervous activities, particularly thermogenic sympathetic activity as a modulator of energy metabolism without any adverse effects on cardiac electrical stability.

  6. Prediction of effects of punch shapes on tableting failure by using a multi-functional single-punch tablet press

    Directory of Open Access Journals (Sweden)

    Takashi Osamura

    2017-09-01

    Full Text Available We previously determined “Tableting properties” by using a multi-functional single-punch tablet press (GTP-1. We proposed plotting “Compactability” on the x-axis against “Manufacturability” on the y-axis to allow visual evaluation of “Tableting properties”. Various types of tableting failure occur in commercial drug production and are influenced by the amount of lubricant used and the shape of the punch. We used the GTP-1 to measure “Tableting properties” with different amounts of lubricant and compared the results with those of tableting on a commercial rotary tableting machine. Tablets compressed with a small amount of lubricant showed bad “Manufacturability”, leading to sticking of powder on punches. We also tested various punch shapes. The GTP-1 correctly predicted the actual tableting results for all punch shapes. With punches that were more likely to cause tableting failure, our system predicted the effects of lubricant quantity in the tablet formulation and the occurrence of sticking in the rotary tableting machine.

  7. FORMULATION AND EVALUATION OF MOUTH DISSOLVING TABLET OF ISOSORBIDE MONONITRATE

    Directory of Open Access Journals (Sweden)

    Bhanushali Akash K

    2011-03-01

    Full Text Available The aim of the present study was to formulate and evaluate the mouth dissolving tablets of isosorbide mononitrate. Drug delivery systems are becoming more complex as pharmaceutical scientist acquires better understanding of the physicochemical and biochemical parameters pertinent to their performance. Over the last decade, the demand of fast disintegrating tablet has been growing mainly for geriatric and pediatric patients, because of swallowing difficulties, the characteristics of fast disintegrating tablet for potential emergency treatment. The superdisintegrant used in this study was crospovidone. The tablets were evaluated for weight variation, hardness, friability, wetting time, water absorption ratio, and disintegration time and dissolution study. The tablets were prepared by direct compression method.

  8. Comparative investigations of tablet crushing force testers

    DEFF Research Database (Denmark)

    Sonnergaard, Jørn; Jensen, C.G.; Poulsen, L.

    2005-01-01

    The performance of 16 tablet breaking force testers was evaluated in terms of accuracy, reproducibility and repeatability. Three tablet formulations with different plastic or brittle deformation mechanisms and with target breaking forces of 50, 100 and 150 N were tested. Statistically significant...... by the concept of components of variance was 5-7 % depending on the model tablet excipient. The standard deviation within testers (repeatability) was affected by the type of model formulation showing increasing variability with increasing brittleness of the compressed material. No specific effect of altering...

  9. “Formulation and evaluation of starch acetate matrix tablets in combination with surfactants for controlled release”

    OpenAIRE

    Mahesh Kumar Vishwanadha; B. Shravan Kumar; Rajasri. Ch; Mounika.G; Ramya.D; Saikrupa.B

    2015-01-01

    In the present study, an attempt has been made to evaluate starch acetate in combination with surfactant for the controlled release profile of drug from matrix system. Ibuprofen was used as a model drug to evaluate its release characteristics from different matrices. Starch acetate was synthesized, characterized and then employed in the matrix tablets as a hydrophobic polymer in different ratios in combination with SLS. Formulated tablets were characterized for parameters like thickness, weig...

  10. Model Systems

    Directory of Open Access Journals (Sweden)

    Francisco Rodríguez-Trelles

    1998-12-01

    Full Text Available Current efforts to study the biological effects of global change have focused on ecological responses, particularly shifts in species ranges. Mostly ignored are microevolutionary changes. Genetic changes may be at least as important as ecological ones in determining species' responses. In addition, such changes may be a sensitive indicator of global changes that will provide different information than that provided by range shifts. We discuss potential candidate systems to use in such monitoring programs. Studies of Drosophila subobscura suggest that its chromosomal inversion polymorphisms are responding to global warming. Drosophila inversion polymorphisms can be useful indicators of the effects of climate change on populations and ecosystems. Other species also hold the potential to become important indicators of global change. Such studies might significantly influence ecosystem conservation policies and research priorities.

  11. Porous hydroxyapatite tablets as carriers for low-dosed drugs.

    Science.gov (United States)

    Cosijns, A; Vervaet, C; Luyten, J; Mullens, S; Siepmann, F; Van Hoorebeke, L; Masschaele, B; Cnudde, V; Remon, J P

    2007-09-01

    The present study evaluated an innovative technique for the manufacturing of low-dosed tablets. Tablets containing hydroxyapatite and a pore forming agent (50% (w/w) Avicel PH 200/20, 37.5% and 50% corn starch/37.5% sorbitol) were manufactured by direct compression followed by sintering. The influence of pore forming agent (type and concentration), sinter temperature and sinter time on tablet properties was investigated. Sintering (1250 degrees C) revealed tablets with an acceptable friability (manufactured using a modified gelcasting technique yielding tablets with a median pore size of 60 and 80 microm. Release from these tablets was drastically increased indicating that the permeability of the tablets was influenced by the pore size, shape and connectivity of the porous network. Changing and controlling these parameters made it possible to obtain drug delivery systems providing different drug delivery behaviour.

  12. Robust calibrations on reduced sample sets for API content prediction in tablets: definition of a cost-effective NIR model development strategy.

    Science.gov (United States)

    Pieters, Sigrid; Saeys, Wouter; Van den Kerkhof, Tom; Goodarzi, Mohammad; Hellings, Mario; De Beer, Thomas; Heyden, Yvan Vander

    2013-01-25

    Owing to spectral variations from other sources than the component of interest, large investments in the NIR model development may be required to obtain satisfactory and robust prediction performance. To make the NIR model development for routine active pharmaceutical ingredient (API) prediction in tablets more cost-effective, alternative modelling strategies were proposed. They used a massive amount of prior spectral information on intra- and inter-batch variation and the pure component spectra to define a clutter, i.e., the detrimental spectral information. This was subsequently used for artificial data augmentation and/or orthogonal projections. The model performance improved statistically significantly, with a 34-40% reduction in RMSEP while needing fewer model latent variables, by applying the following procedure before PLS regression: (1) augmentation of the calibration spectra with the spectral shapes from the clutter, and (2) net analyte pre-processing (NAP). The improved prediction performance was not compromised when reducing the variability in the calibration set, making exhaustive calibration unnecessary. Strong water content variations in the tablets caused frequency shifts of the API absorption signals that could not be included in the clutter. Updating the model for this kind of variation demonstrated that the completeness of the clutter is critical for the performance of these models and that the model will only be more robust for spectral variation that is not co-linear with the one from the property of interest.

  13. New simple image overlay system using a tablet PC for pinpoint identification of the appropriate site for anastomosis in peripheral arterial reconstruction.

    Science.gov (United States)

    Mochizuki, Yasuaki; Hosaka, Akihiro; Kamiuchi, Hiroki; Nie, Jun Xiao; Masamune, Ken; Hoshina, Katsuyuki; Miyata, Tetsuro; Watanabe, Toshiaki

    2016-12-01

    To evaluate the accuracy and utility of a new image overlay system using a tablet PC for patients undergoing peripheral arterial reconstruction. Eleven limbs treated with distal bypass surgery were studied. Three-dimensional images obtained by processing a preoperative contrast-enhanced computed tomography scan were superimposed onto the back-camera images of a tablet PC. We used this system to pinpoint a planned distal anastomotic site preoperatively and to make a precise incision directly above it during surgery. We used a branch artery near the distal anastomotic site as a reference point and the accuracy of the system was validated by comparing its results with the intraoperative findings. The precision of the system was also compared with that of a preoperative ultrasonographic examination. Both the image overlay system and ultrasonography (US) accurately identified the target branch artery in all except one limb. In that limb, which had a very small reference branch artery, preoperative US wrongly identified another branch, whereas the image overlay system located the target branch with an error of 10 mm. Our image overlay system was easy to use and allowed us to precisely identify a target artery preoperatively. Therefore, this system could be helpful for pinpointing the most accurate incision site during surgery.

  14. IVIVC in oral absorption for fenofibrate immediate release tablets using a dissolution/permeation system.

    Science.gov (United States)

    Buch, Philipp; Langguth, Peter; Kataoka, Makoto; Yamashita, Shinji

    2009-06-01

    The usefulness of a dissolution/permeation (D/P) system to predict the in vivo performance of solid dosage forms containing the poorly soluble drug, fenofibrate, was studied. Biorelevant dissolution media simulating the fasted and fed state conditions of the human gastrointestinal tract were used in order to simulate the effect of food on the absorption of fenofibrate. Moreover, the results obtained from the D/P system were correlated with pharmacokinetic parameters obtained following in vivo studies in rats. The in vitro parameter (amount permeated in the D/P system) reflected well the in vivo performance in rats in terms of AUC and C(max) of fenofibric acid. This study thus demonstrates the potential of the D/P system as valuable tool for absorption screening of dosage forms for poorly soluble drugs. (c) 2008 Wiley-Liss, Inc.

  15. Tablet Technologies and Education

    OpenAIRE

    Heidi L. Schnackenberg

    2013-01-01

    Recently, tablet technologies have grown tremendously in popularity. They lend themselves to a myriad of learning modalities and therefore may be well suited to use in schools and universities. While teachers work to find useful applications for tablets, students have already begun using them at home and, in secondary and higher education, in classes. Unfortunately, sometimes when students use tablets for courses they play with “apps,” rather than using the technology as a useful and powerful...

  16. Optimization of fast dissolving etoricoxib tablets prepared by sublimation technique

    Directory of Open Access Journals (Sweden)

    Patel D

    2008-01-01

    Full Text Available The purpose of this investigation was to develop fast dissolving tablets of etoricoxib. Granules containing etoricoxib, menthol, crospovidone, aspartame and mannitol were prepared by wet granulation technique. Menthol was sublimed from the granules by exposing the granules to vacuum. The porous granules were then compressed in to tablets. Alternatively, tablets were first prepared and later exposed to vacuum. The tablets were evaluated for percentage friability and disintegration time. A 3 2 full factorial design was applied to investigate the combined effect of 2 formulation variables: amount of menthol and crospovidone. The results of multiple regression analysis indicated that for obtaining fast dissolving tablets; optimum amount of menthol and higher percentage of crospovidone should be used. A surface response plots are also presented to graphically represent the effect of the independent variables on the percentage friability and disintegration time. The validity of a generated mathematical model was tested by preparing a checkpoint batch. Sublimation of menthol from tablets resulted in rapid disintegration as compared with the tablets prepared from granules that were exposed to vacuum. The optimized tablet formulation was compared with conventional marketed tablets for percentage drug dissolved in 30 min (Q 30 and dissolution efficiency after 30 min (DE 30 . From the results, it was concluded that fast dissolving tablets with improved etoricoxib dissolution could be prepared by sublimation of tablets containing suitable subliming agent.

  17. Optimization of fast dissolving etoricoxib tablets prepared by sublimation technique.

    Science.gov (United States)

    Patel, D M; Patel, M M

    2008-01-01

    The purpose of this investigation was to develop fast dissolving tablets of etoricoxib. Granules containing etoricoxib, menthol, crospovidone, aspartame and mannitol were prepared by wet granulation technique. Menthol was sublimed from the granules by exposing the granules to vacuum. The porous granules were then compressed in to tablets. Alternatively, tablets were first prepared and later exposed to vacuum. The tablets were evaluated for percentage friability and disintegration time. A 3(2) full factorial design was applied to investigate the combined effect of 2 formulation variables: amount of menthol and crospovidone. The results of multiple regression analysis indicated that for obtaining fast dissolving tablets; optimum amount of menthol and higher percentage of crospovidone should be used. A surface response plots are also presented to graphically represent the effect of the independent variables on the percentage friability and disintegration time. The validity of a generated mathematical model was tested by preparing a checkpoint batch. Sublimation of menthol from tablets resulted in rapid disintegration as compared with the tablets prepared from granules that were exposed to vacuum. The optimized tablet formulation was compared with conventional marketed tablets for percentage drug dissolved in 30 min (Q(30)) and dissolution efficiency after 30 min (DE(30)). From the results, it was concluded that fast dissolving tablets with improved etoricoxib dissolution could be prepared by sublimation of tablets containing suitable subliming agent.

  18. Development and Characterization of Novel Floating-Mucoadhesive Tablets Bearing Venlafaxine Hydrochloride

    Directory of Open Access Journals (Sweden)

    Raghvendra Misra

    2016-01-01

    Full Text Available The present investigation is concerned about the development of floating bioadhesive drug delivery system of venlafaxine hydrochloride which after oral administration exhibits a unique combination of floating and bioadhesion to prolong gastric residence time and increase drug bioavailability within the stomach. The floating bioadhesive tablets were prepared by the wet granulation method using different ratios of hydroxypropyl methyl cellulose (HPMC K4MCR and Carbopol 934PNF as polymers. Sodium bicarbonate (NaHCO3 and citric acid were used as gas (CO2 generating agents. Tablets were characterized for floating properties, in vitro drug release, detachment force, and swelling index. The concentration of hydroxypropyl methyl cellulose and Carbopol 934PNF significantly affects the in vitro drug release, floating properties, detachment force, and swelling properties of the tablets. The optimized formulation showed the floating lag time 72±2.49 seconds and duration of floating 24.50±0.74 hr. The in vitro release studies and floating behavior were studied in simulated gastric fluid (SGF at pH 1.2. Different drug release kinetics models were also applied. The in vitro drug release from tablets was sufficiently sustained (more than 18 hr and the Fickian transports of the drug from the tablets were confirmed. The radiological evidence suggests that the tablets remained buoyant and altered position in the stomach of albino rabbit and mean gastric residence time was prolonged (more than > 6 hr.

  19. A novel multi-unit tablet for treating circadian rhythm diseases.

    Science.gov (United States)

    Liu, Qi; Gong, Yinhua; Shi, Yun; Jiang, Liqun; Zheng, Chunli; Ge, Liang; Liu, Jianping; Zhu, Jiabi

    2013-06-01

    This study aimed to develop and evaluate a novel multi-unit tablet that combined a pellet with a sustained-release coating and a tablet with a pulsatile coating for the treatment of circadian rhythm diseases. The model drug, isosorbide-5-mononitrate, was sprayed on microcrystalline cellulose (MCC)-based pellets and coated with Eudragit(®) NE30D, which served as a sustained-release layer. The coated pellets were compressed with cushion agents (a mixture of MCC PH-200/ MCC KG-802/PC-10 at a ratio of 40:40:20) at a ratio of 4:6 using a single-punch tablet machine. An isolation layer of OpadryII, swellable layer of HPMC E5, and rupturable layer of Surelease(®) were applied using a conventional pan-coating process. Central-composite design-response surface methodology was used to investigate the influence of these coatings on the square of the difference between release times over a 4 h time period. Drug release studies were carried out on formulated pellets and tablets to investigate the release behaviors, and scanning electron microscopy (SEM) was used to monitor the pellets and tablets and their cross-sectional morphology. The experimental results indicated that this system had a pulsatile dissolution profile that included a lag period of 4 h and a sustained-release time of 4 h. Compared to currently marketed preparations, this tablet may provide better treatment options for circadian rhythm diseases.

  20. Tablet splitting: Product quality assessment of metoprolol succinate extended release tablets.

    Science.gov (United States)

    Zhao, Na; Zidan, Ahmed; Tawakkul, Mobin; Sayeed, Vilayat A; Khan, Mansoor

    2010-11-30

    Metoprolol succinate extended release tablets comprise a multiple unit system containing metoprolol succinate in a multitude of controlled release pellets. Each pellet acts as a separate drug delivery unit and is designed to deliver metoprolol continuously over the dosage interval. Despite the flexibility that controlled release pellets may offer, segregation is one of the challenges that commonly occur during tableting for such drug delivery system. Since all commercial metoprolol succinate extended release tablets are scored, they are deemed suitable for splitting. The present study was aimed at utilizing an innovative technology to determine the dose uniformity for split tablets. Four marketed drug products consisting of innovator and generics were evaluated for effect of splitting on weight, assay and content uniformity. Novel analytical tool such as near infrared (NIR) chemical imaging was used to visualize the distribution of metoprolol succinate and functional excipients on the surfaces of the marketed tablets. The non-homogeneous distribution of directly compressed metoprolol succinate beads on the surface of the tablets as well as the split intersection explained the large variation in the split tablets' weight and content uniformity results. The obtained results indicated the usefulness of NIR chemical imaging to determine the need for content uniformity studies for certain split tablets.

  1. Development and Evaluation of a Novel Pellet-Based Tablet System for Potential Colon Delivery of Budesonide

    Directory of Open Access Journals (Sweden)

    Jaleh Varshosaz

    2012-01-01

    Full Text Available Budesonide, a potent glucocorticoid, is used for the treatment of inflammatory bowel diseases. Current available oral formulations of budesonide have low efficacy against ulcerative colitis because of the premature drug release in the upper part of the gastrointestinal tract. In this paper a pH- and time-controlled colon-targeted pellet-based tablet of budesonide was established. Pellet cores were prepared by extrusion-spheronization method and further coated with xanthan gum (barrier layer, Eudragit NE30D and L30D55 combination (inner layer, and Eudragit FS30 (as enteric layer sequentially to achieve the required release profile. The coated pellets then compressed into tablets using inert tabletting granules of Cellactose or Pearlitol. Release studies, performed in simulated gastric, intestinal, and colon pH were used in sequence to mimic the gastrointestinal transit. The influence of formulation variables like barrier layer thickness, inner layer composition, and enteric coat thickness on drug release were investigated and the coated pellets that contained 12% weight gain in xanthan gum layer, Eudragit L30D55 and Eudragit NE30D with a ratio of 3 : 7 in inner layer with 30% weight gain and 25% weight gain in Eudragit FS layer were found to protect the drug release in stomach and small intestine and 83.35 ± 2.4 of budesonide was released at 24 h. The drug release from the tablets prepared using 40% Cellactose 80 as tableting excipient was found to be closely similar to that of uncompressed pellets.

  2. Influence of tablet splitting on content uniformity of lisinopril/hydrochlorthiazide tablets.

    Science.gov (United States)

    Vranić, Edina; Uzunović, Alija

    2007-11-01

    Dose-related adverse effects of medications are a major problem in modern medical practice. The "correct" dose, based on drug company guidelines in package inserts, may not be correct for many patients. Tablet splitting or dividing has been an accepted practice for many years as a means of obtaining the prescribed dose of medication. As model tablets for this investigation, two batches of lisinopril- hydrochlorothiazide scored tablets labeled to contain 20/12.5 mg were used. The aim of this study was to establish possible influence of tablet splitting on content uniformity of lisinopril/hydrochlorthiazide tablets. Determination of the content uniformity of lisinopril and hydrochlorthiazide in our batches, was carried out by HPLC method. The results of content uniformity studies for halves of tablets containing combination of lisinopril-hydrochlorthiazide (supposed to contain 50% of stated 20/12.5 mg in the whole tablet) were: 49.60 +/-3.29% and 49.29+/-0.60 % (lisinopril); 50.33+/-3.50% and 50.69+/-1.95% (hydrochlorthiazide) for batch I and II, respectively. We can conclude that the results obtained in this study support an option of tablet splitting, which is very important for obtaining the required dosage when a dosage form of the required strength is unavailable, and for better individualization of the therapy.

  3. Calcification prevention tablets

    Science.gov (United States)

    Lindsay, Geoffrey A.; Hasting, Michael A.; Gustavson, Michael A.

    1991-01-01

    Citric acid tablets, which slowly release citric acid when flushed with water, are under development by the Navy for calcification prevention. The citric acid dissolves calcium carbonate deposits and chelates the calcium. For use in urinals, a dispenser is not required because the tablets are non-toxic and safe to handle. The tablets are placed in the bottom of the urinal, and are consumed in several hundred flushes (the release rate can be tailored by adjusting the formulation). All of the ingredients are environmentally biodegradable. Mass production of the tablets on commercial tableting machines was demonstrated. The tablets are inexpensive (about 75 cents apiece). Incidences of clogged pipes and urinals were greatly decreased in long term shipboard tests. The corrosion rate of sewage collection pipe (90/10 Cu/Ni) in citric acid solution in the laboratory is several mils per year at conditions typically found in traps under the urinals. The only shipboard corrosion seen to date is of the yellow brass urinal tail pieces. While this is acceptable, the search for a nontoxic corrosion inhibitor is underway. The shelf life of the tablets is at least one year if stored at 50 percent relative humidity, and longer if stored in sealed plastic buckets.

  4. Implementation of an advanced hybrid MPC-PID control system using PAT tools into a direct compaction continuous pharmaceutical tablet manufacturing pilot plant.

    Science.gov (United States)

    Singh, Ravendra; Sahay, Abhishek; Karry, Krizia M; Muzzio, Fernando; Ierapetritou, Marianthi; Ramachandran, Rohit

    2014-10-01

    It is desirable for a pharmaceutical final dosage form to be manufactured through a quality by design (QbD)-based approach rather than a quality by testing (QbT) approach. An automatic feedback control system coupled with PAT tools that is part of the QbD paradigm shift, has the potential to ensure that the pre-defined end product quality attributes are met in a time and cost efficient manner. In this work, an advanced hybrid MPC-PID control architecture coupled with real time inline/online monitoring tools and principal components analysis (PCA) based additional supervisory control layer has been proposed for a continuous direct compaction tablet manufacturing process. The advantages of both MPC and PID have been utilized in a hybrid scheme. The control hardware and software integration and implementation of the control system has been demonstrated using feeders and blending unit operation of a continuous tablet manufacturing pilot plant and an NIR based PAT tool. The advanced hybrid MPC-PID control scheme leads to enhanced control loop performance of the critical quality attributes in comparison to a regulatory (e.g. PID) control scheme indicating its potential to improve pharmaceutical product quality.

  5. Creating Electronic Books-Chapters for Computers and Tablets Using Easy Java/JavaScript Simulations, EjsS Modeling Tool

    CERN Document Server

    Wee, Loo Kang

    2015-01-01

    This paper shares my journey (tools used, design principles derived and modeling pedagogy implemented) when creating electronic books-chapters (epub3 format) for computers and tablets using Easy Java/JavaScript Simulations, (old name EJS, new EjsS) Modeling Tool. The theory underpinning this work grounded on learning by doing through dynamic and interactive simulation-models that can be more easily made sense of instead of the static nature of printed materials. I started combining related computer models with supporting texts and illustrations into a coherent chapter, a logical next step towards tighter support for teachers and students ,developing prototypes electronic chapters on the topics of Simple Harmonic Motion and Gravity customized for the Singapore-Cambridge General Certificate of Education Advanced Level (A-level). I aim to inspire more educators to create interactive and open educational resources for the benefit of all. Prototypes: http://iwant2study.org/ospsg/index.php/interactive-resources/phy...

  6. The use of the SeDeM diagram expert system for the formulation of Captopril SR matrix tablets by direct compression.

    Science.gov (United States)

    Saurí, J; Millán, D; Suñé-Negre, J M; Pérez-Lozano, P; Sarrate, R; Fàbregas, A; Carrillo, C; Miñarro, M; Ticó, J R; García-Montoya, E

    2014-01-30

    The SeDeM diagram expert system has been used to study excipients, Captopril and designed formulations for their galenic characterization and to ascertain the critical points of the formula affecting product quality to obtain suitable formulations of Captopril direct compression SR matrix tablets. The application of the SeDeM diagram expert system enables selecting excipients with in order to optimize the formula in the preformulation and formulation studies. The methodology is based on the implementation of ICH Q8, establishing the design space of the formula with the use of experiment design, using the parameters of the SeDeM diagram expert system as system responses. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Effect of Fujian tablet on the expression of Nogo-A mRNA in the cervical spinal cord of middle cerebral artery occlusion model rats

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Inhibiting the expression of Nogo-A in cervical spinal cord by use of interaction of antigen and antibody can help the remodeling of corticospinal projection of focal cerebral ischemia model rats to facilitate neurological recovery, which provides a new possible mechanism for drugs to promote neurological recovery. However, the effects of drugs on the expression of Nogo-A in cervical spinal cord are still unclear.OBJECTIVE: To observe the effect of Fujian tablet on the expression of Nogo-A mRNA in cervical spinal cords of middle cerebral artery occlusion (MCAO) rats, and to investigate the possible regulatory effect of Fujian tablet on the regenerated microenvironment of spinal conduction bundle.DESIGN: A randomized and controlled trial taking Wistar rats as experimental animals.SETTING: Department of Neurology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine.MATERIALS: This experiment was carried out in the laboratory of Shandong Academy of Medical Science between June 2005 and July 2006. A total of 40 healthy male Wistar rats, aged 12 weeks, weighing 250 -300 g, were provided by the Experimental Animal Center of Shandong University. Fujian tablets (main components: Heshouwu, Yinyanghuo, etc) were provided by office of Pharmaceutics of Shandong University of traditional Chinese medicine. Nogo-A detection kit was provided by Wuhan Boster Biotechnology Co.,Ltd.,and batch number was 040309009. This experiment was approved by Local Animal Ethics Committee.METHODS: Forty male rats were randomly divided into 4 groups, with 10 in each: normal group,sham-operation group, model group and administration group. Rats in the administration group and model group were subjected to MCAO. Rats in the sham-operation group underwent the same craniotomy, and their middle cerebral arteries (MCA) were not occluded. Rats in the normal group were untouched. Rats in administration group were intragastrically administrated with the solution of Fujian

  8. Amorphization within the tablet

    DEFF Research Database (Denmark)

    Doreth, Maria; Hussein, Murtadha Abdul; Priemel, Petra A.

    2017-01-01

    , the feasibility of microwave irradiation to prepare amorphous solid dispersions (glass solutions) in situ was investigated. Indomethacin (IND) and polyvinylpyrrolidone K12 (PVP) were tableted at a 1:2 (w/w) ratio. In order to study the influence of moisture content and energy input on the degree of amorphization......, tablet formulations were stored at different relative humidity (32, 43 and 54% RH) and subsequently microwaved using nine different power-time combinations up to a maximum energy input of 90 kJ. XRPD results showed that up to 80% (w/w) of IND could be amorphized within the tablet. mDSC measurements...

  9. Android tablets for dummies

    CERN Document Server

    Gookin, Dan

    2015-01-01

    Learn all you need to know about your Android tablet in one quick and easy reference! It's not a computer and it's not a smartphone-so what in the world is it? Whether you're new to Android or new to tablets altogether, you're about to experience mobile computing like never before with this fun, full-color guide! Inside, longtime and bestselling author Dan Gookin walks you through setting up your Android tablet, navigating the interface, browsing the web, setting up email, connecting to social media, finding plenty of apps, music, books, and movies to indulge your interests-and so much more.

  10. Continuous system modeling

    Science.gov (United States)

    Cellier, Francois E.

    1991-01-01

    A comprehensive and systematic introduction is presented for the concepts associated with 'modeling', involving the transition from a physical system down to an abstract description of that system in the form of a set of differential and/or difference equations, and basing its treatment of modeling on the mathematics of dynamical systems. Attention is given to the principles of passive electrical circuit modeling, planar mechanical systems modeling, hierarchical modular modeling of continuous systems, and bond-graph modeling. Also discussed are modeling in equilibrium thermodynamics, population dynamics, and system dynamics, inductive reasoning, artificial neural networks, and automated model synthesis.

  11. Revision of Import and Export Requirements for Controlled Substances, Listed Chemicals, and Tableting and Encapsulating Machines, Including Changes To Implement the International Trade Data System (ITDS); Revision of Reporting Requirements for Domestic Transactions in Listed Chemicals and Tableting and Encapsulating Machines; and Technical Amendments. Final rule.

    Science.gov (United States)

    2016-12-30

    The Drug Enforcement Administration is updating its regulations for the import and export of tableting and encapsulating machines, controlled substances, and listed chemicals, and its regulations relating to reports required for domestic transactions in listed chemicals, gamma-hydroxybutyric acid, and tableting and encapsulating machines. In accordance with Executive Order 13563, the Drug Enforcement Administration has reviewed its import and export regulations and reporting requirements for domestic transactions in listed chemicals (and gamma-hydroxybutyric acid) and tableting and encapsulating machines, and evaluated them for clarity, consistency, continued accuracy, and effectiveness. The amendments clarify certain policies and reflect current procedures and technological advancements. The amendments also allow for the implementation, as applicable to tableting and encapsulating machines, controlled substances, and listed chemicals, of the President's Executive Order 13659 on streamlining the export/import process and requiring the government-wide utilization of the International Trade Data System (ITDS). This rule additionally contains amendments that implement recent changes to the Controlled Substances Import and Export Act (CSIEA) for reexportation of controlled substances among members of the European Economic Area made by the Improving Regulatory Transparency for New Medical Therapies Act. The rule also includes additional substantive and technical and stylistic amendments.

  12. Formulation and Evaluation of Aceclofenac Liquisolid Tablets

    Directory of Open Access Journals (Sweden)

    Kankudte A.D

    2013-07-01

    Full Text Available In the present study, the potential of liquisolid systems to improve the dissolution properties of poorly water soluble agents was investigated using Aceclofenac. Aceclofenac is a Non steroidal anti-inflammatory drug used orally for treatment. According to BCS, Aceclofenac is class II compound i.e. poorly water soluble. The in vitro release pattern of LS compacts and directly compressed tablets were studied using USP-II apparatus. Different LS compacts were prepared using a mathematical model to calculate the required quantities of powder and liquid ingredients to produce acceptably flowable and compressible admixture. Avicel PH 102, Aerosil 200 and Sodium starch Glycolate were employed as carrier, coating material and disintegrant respectively for preparing LS comp. The prepared LS compacts were evaluated for their flow properties such as bulk density, tapped density, angle of repose, Carr’s compressibility index and Hausner’s ratio. Liquisolid compacts demonstrated significantly higher drug release rates in dissolution media compared to tablets prepared by the direct compression method. This was due to an increase in wetting properties and surface of drug available for dissolution.

  13. Justification of Drug Product Dissolution Rate and Drug Substance Particle Size Specifications Based on Absorption PBPK Modeling for Lesinurad Immediate Release Tablets.

    Science.gov (United States)

    Pepin, Xavier J H; Flanagan, Talia R; Holt, David J; Eidelman, Anna; Treacy, Don; Rowlings, Colin E

    2016-09-01

    In silico absorption modeling has been performed, to assess the impact of in vitro dissolution on in vivo performance for ZURAMPIC (lesinurad) tablets. The dissolution profiles of lesinurad tablets generated using the quality control method were used as an input to a GastroPlus model to estimate in vivo dissolution in the various parts of the GI tract and predict human exposure. A model was set up, which accounts for differences of dosage form transit, dissolution, local pH in the GI tract, and fluid volumes available for dissolution. The predictive ability of the model was demonstrated by confirming that it can reproduce the Cmax observed for independent clinical trial. The model also indicated that drug product batches that pass the proposed dissolution specification of Q = 80% in 30 min are anticipated to be bioequivalent to the clinical reference batch. To further explore the dissolution space, additional simulations were performed using a theoretical dissolution profile below the proposed specification. The GastroPlus modeling indicates that such a batch will also be bioequivalent to standard clinical batches despite having a dissolution profile, which would fail the proposed dissolution specification of Q = 80% in 30 min. This demonstrates that the proposed dissolution specification sits comfortably within a region of dissolution performance where bioequivalence is anticipated and is not near an edge of failure for dissolution, providing additional confidence to the proposed specifications. Finally, simulations were performed using a virtual drug substance batch with a particle size distribution at the limit of the proposed specification for particle size. Based on these simulations, such a batch is also anticipated to be bioequivalent to clinical reference, demonstrating that the proposed specification limits for particle size distribution would give products bioequivalent to the pivotal clinical batches.

  14. Tablet Computer Literacy Levels of the Physical Education and Sports Department Students

    OpenAIRE

    Gulten HERGUNER

    2016-01-01

    Education systems are being affected in parallel by newly emerging hardware and new developments    occurring in technology daily. Tablet usage especially is becoming ubiquitous in the teaching‐learning processes in recent years. Therefore, using the tablets effectively, managing them and having a high level of tablet literacy play an important role within the education system. This study aimed at determining the tablet literacy levels of students in the Physical Education and ...

  15. Grasp interaction with tablets

    CERN Document Server

    Wolf, Katrin

    2015-01-01

    This book presents guidelines for a future device type: a tablet that allows ergonomic front- and back-of-device interaction. These guidelines help designers and developers of user interfaces to build ergonomic applications for tablet devices, in particular for devices that enable back-of-device interaction. In addition, manufacturers of tablet devices obtain arguments that back-of-device interaction is a promising extension of the interaction design space and results in increased input capabilities, enriched design possibilities, and proven usability. The guidelines are derived from empirical studies and developed to fit the users’ skills to the way the novel device type is held. Three particular research areas that are relevant to develop design guidelines for tablet interaction are investigated: ergonomic gestures, interaction areas, and pointing techniques.

  16. Olaparib tablet formulation

    DEFF Research Database (Denmark)

    Plummer, Ruth; Swaisland, Helen; Leunen, Karin

    2015-01-01

    BACKGROUND: The oral PARP inhibitor olaparib has shown efficacy in patients with BRCA-mutated cancer. This Phase I, open-label, three-part study (Parts A-C) in patients with advanced solid tumours evaluated the effect of food on the pharmacokinetics (PK) of olaparib when administered in tablet...... formulation. METHODS: PK data were obtained in Part A using a two-treatment period crossover design; single-dose olaparib 300 mg (two 150 mg tablets) was administered in two prandial states: fasted and fed. In Part B, patients received olaparib tablets (300 mg bid) for 5 days under fasting conditions; in Part...... exposure to olaparib 300 mg tablets, although in the absence of an effect on the extent of olaparib absorption....

  17. Development and Efficacy Assessment of an Enteric Coated Porous Tablet Loaded With F4 Fimbriae for Oral Vaccination of Piglets against F4+ Escherichia coli Infections.

    Science.gov (United States)

    Srivastava, Atul; Gowda, D V; Madhunapantula, SubbaRao V; Siddaramaiah

    2016-01-01

    Enterotoxigenic Escherichia coli (ETEC) infection is one of the major causes contributing to the development of diarrhoea and mortality in new born, suckling and newly weaned piglets. To date, no preventive/treatment strategy showed promising results, which could be due to the lack of potent vaccines, and/or due to the development of resistance of ETEC to antibiotics. Therefore, in the present investigation, a novel porous sodium alginate (SA) tablet formulation loaded with F4 fimbriae antigen was developed and tested for efficacy against ETEC infections in piglet models. Precompression parameters of the powder mixes and post compression parameters of tablets have been evaluated and results were found to be satisfactory. Loading of F4 fimbrial antigens into the tablets was achieved by inducing pores in the tablets via the sublimation of camphor followed by incubation with purified F4 fimbriae. The loaded tablets have been coated with Eudragit L100 to protect the F4 fimbriae from (a) highly acidic gastric environment; (b) proteolytic cleavage by pepsin; and (c) to promote subsequent release in the intestine. Evaluation of developed F4 fimbrial tablets in a Pig model demonstrated induction of mucosal immunity, and a significant reduction of F4+ E. coli in faeces. Therefore, F4 fimbriae loaded porous tablets could be a novel oral vaccination candidate to induce mucosal and systemic immunity against ETEC infections.

  18. EFFECT OF LUMINAL pH CHANGES ON GUAR GUM-HPMC E15 LV MIXED MATRIX TABLETS FOR MESALAMINE DRUG DELIVERY TO COLON AND STUDY ON IN- VITRO CHARACTERISTICS IN TWO DIFFERENT DISSOLUTION MODELS vs. MARKETED FORMULATION

    Directory of Open Access Journals (Sweden)

    A. Maria John Newton*, L. Prabakaran and K.N. Jayaveera

    2012-07-01

    Full Text Available The study was designed to investigate the impact of colonic pH changes on formulated colon targeted Mesalamine matrix tablets in the treatment of inflammatory bowel disease (IBD. Mesalamine tablets were fabricated with guar gum as Polymer system. The different batches of Mesalamine tablets (GMM1-GMM6 were compressed with increasing proportion of guar gum and HPMC E15 LV. The different buffer conditions were chosen to mimic the pH changes in terminal part of the ileum as well as the colon. A separate two in vitro studies were conducted in all the formulations. The impact of the pH changes on the coated tablets in normal pH condition and reduced pH condition (pH reduced during IBD were compared. In IBD the pH of the colon falls below its normal level. The extent of pH change depends on the severity of the disease. The study was designed to evaluate the in vitro dissolution characteristics of Mesalamine matrix tablets in a variety of simulated fluids (pH range 1.2, 6, 6.8, 7.2, 5. The results indicated that the impact of pH changes on drug release profile was not affected in the diseased and normal pH condition of the colon. The present treatment methods of IBD mostly depend on pH sensitivity polymers or enteric coating technique. These pH sensitive polymers based colonic devices may not serve the patient needs successfully because the influence of colonic pH on pH sensitive polymer based devices plays an important role in triggering the drug release in target site. The lowered pH condition in diseased state could not trigger the drug release in pH sensitive polymer based devices as it was not the threshold pH of the particular coated polymer. In case of enteric coating there may be a possibility of disintegration of the tablet before reaching the colon due to the contractile movement of GI tract and fluctuation in the GI pH. The present matrix tablets were prepared with guar gum, which cannot be affected by the pH changes of the colon, maintained

  19. Evaluation of the performance characteristics of bilayer tablets: Part II. Impact of environmental conditions on the strength of bilayer tablets.

    Science.gov (United States)

    Kottala, Niranjan; Abebe, Admassu; Sprockel, Omar; Bergum, James; Nikfar, Faranak; Cuitiño, Alberto M

    2012-12-01

    Ambient air humidity and temperature are known to influence the mechanical strength of tablets. The objective of this work is to understand the influence of processing parameters and environmental conditions (humidity and temperature) on the strength of bilayer tablets. As part of this study, bilayer tablets were compressed with different layer ratios, dwell times, layer sequences, material properties (plastic and brittle), first and second layer forces, and lubricant concentrations. Compressed tablets were stored in stability chambers controlled at predetermined conditions (40C/45%RH, 40C/75%RH) for 1, 3, and 5 days. The axial strength of the stored tablets was measured and a statistical model was developed to determine the effects of the aforementioned factors on the strength of bilayer tablets. As part of this endeavor, a full 3 × 2(4) factorial design was executed. Responses of the experiments were analyzed using PROC GLM of SAS (SAS Institute Inc, Cary, North Carolina, USA). A model was fit using all the responses to determine the significant interactions (p < 0.05). Results of this study indicated that storage conditions and storage time have significant impact on the strength of bilayer tablets. For Avicel-lactose and lactose-Avicel tablets, tablet strength decreased with the increasing humidity and storage time. But for lactose-lactose tablets, due to the formation of solid bridges upon storage, an increase in tablet strength was observed. Significant interactions were observed between processing parameters and storage conditions on the strength of bilayer tablets.

  20. Development of time controlled chronomodulated tablet with swelling and rupturable layers: Optimization of factors influencing lag-time and drug release

    OpenAIRE

    Desai, Mayur; Rishad R. Jivani; Patel, Laxman D; Jivani, Noordin P; Sonagara, Bhavin

    2012-01-01

    Introduction: A tablet system consisting of cores coated with two layers of swelling and rupturable coatings was prepared and evaluated as time controlled chronomodulated tablet. Materials and Methods: Cores containing Montelukast sodium as model drug were prepared by direct compression and then coated sequentially with an inner swelling layer containing a HPMC E 5 and an outer rupturable layer of Eudragit RL/RS (1:1). A three-factor, two-level, full factorial design was used to investigate t...

  1. Preparation and pharmaceutical evaluation of acetaminophen nano-fiber tablets: Application of a solvent-based electrospinning method for tableting.

    Science.gov (United States)

    Hamori, Mami; Nagano, Kana; Kakimoto, Sayaka; Naruhashi, Kazumasa; Kiriyama, Akiko; Nishimura, Asako; Shibata, Nobuhito

    2016-03-01

    In this study, we developed nano-fiber-based tablets with acetaminophen (AAP; LogPow=0.51) for controlled-release delivery systems and evaluated in vitro drug dissolution and in vivo pharmacokinetics in rats. Nano-fibers made from methacrylic acid copolymer S (MAC; EUDRAGIT S100) and containing AAP were prepared using a solvent-based electrospinning (ES) method. In vitro dissolution rate profiles of AAP showed tableting pressure-dependent decreases and pH-dependent increases. The results of tablet tracking by X-ray irradiation showed tablets based on MAC nano-fibers did not disintegrate in the upper intestinal lumen and had the properties of a long-term-acting tablet. In addition, the in vitro release profiles of AAP from nano-fiber tablets prepared by dissolving MAC with AAP (NFT), nano-fiber tablets prepared by adsorbing AAP to drug-free MAC nano-fibers (NFTadso), and tablets prepared by adsorbing half the amount of AAP to MAC nano-fibers containing the remaining amount of AAP (NFThalf) showed independent controlled-release aspects of AAP compared with physical mixture tablets (PMT). In vivo pharmacokinetic studies in rats after intraduodenal administration of 14 mg/rat AAP in NFT, NFTadso, and NFThalf demonstrated that all these tablets based on MAC nano-fibers showed sustained-release profiles compared with PMT, and showed ultra-sustained release properties for AAP. These new tablets based on MAC nano-fibers did not disintegrate in the intestine in the lower pH region, and the tablets could regulate the release of AAP in a pH-dependent manner. The ES method is a useful technique to prepare nano-fibers and showed promising results as an oral delivery system for sustained-release regulation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  2. Establishment of Near Infrared Quantitative Model of Lacidophilin Tablets%乳酸菌素片近红外定量模型的建立

    Institute of Scientific and Technical Information of China (English)

    张继红

    2015-01-01

    目的:建立乳酸菌素片近红外光谱定量模型。方法:采用光纤型近红外漫反射光谱法分析和偏最小二乘法,经内部交叉验证,建立了同厂家乳酸菌素片中乳酸菌素的定量校正模型,用建立的定量校正模型对验证集样品进行预测。结果:乳酸菌素片定量模型预测结果的相对偏差小于2.0%。结论:利用近红外光谱技术对药品进行快速无损伤定量分析是可行的,通过这些研究,发明一种适用于基层稽查人员快速控制其质量的工具,同时也可应用于产品的在线质量控制。%Objective: To establish a near infrared quantitative model for lacidophilin tablets . Methods: The quantitative calibration model of lactein in lacidophilin tablets was set up using near infrared diffuse reflectance spectrophotometry ( NIRDRS ) and PLS ( partial least squares ) regression through cross-validation in the same manufacturer . The established quantitative calibration model was used for the prediction of validation samples . Results: The relative deviation of predicted results of quantitative model of lacidophilin tablets was less than 2 . 0%. Conclusion: It is feasible to use near infrared spectroscopy technology for the rapid non-destructive quantitative analysis of drugs . Based on this research , a quality control tool is to be developed which is applicable to the inspectors at the grass-roots level in product quality supervision , and also can be applied to the on-line quality control of products .

  3. Conscious and anaesthetised Göttingen mini-pigs as an in-vivo model for buccal absorption - pH-dependent absorption of metoprolol from bioadhesive tablets

    DEFF Research Database (Denmark)

    Meng-Lund, Emil; Jacobsen, Jette; Andersen, Morten B

    2014-01-01

    significantly different to the buccal anaesthetised groups (120 ± 0 and 165 ± 15 min) for buccal tablet pH 6.2 and pH 8.9, respectively. Also, the absolute bioavailability from the anaesthetised buccal tablet pH 8.9 (20.7 ± 4.0%) had a significant increase compared to all other buccal tablet groups...

  4. Evaluation of honey locust (Gleditsia triacanthos Linn.) gum as sustaining material in tablet dosage forms.

    Science.gov (United States)

    Uner, Melike; Altinkurt, Turan

    2004-07-01

    In this study, honey locust gum (HLG) obtained from Gleditsia triacanthos (honey locust) beans was investigated as a hydrophilic matrix material in the tablets prepared at different concentrations (5% and 10%) by wet granulation method. Theophylline was chosen as a model drug. The matrix tablets containing hydroxyethylcellulose and hydroxypropyl methylcellulose as sustaining polymers at the same concentrations were prepared and a commercial sustained release (CSR) tablet containing 200 mg theophylline was examined for comparison of HLG performance. Physical analysis on CSR tablet, matrix tablets and their granules before compression were performed. According to the results obtained from dissolution studies in distilled water, pH 1.2 HCl buffer and pH 7.2 phosphate buffer, no significant difference was found between CSR tablet and the matrix tablet containing 10% HLG in each medium (P > 0.05) and these tablets showed zero-order kinetic model in all the mediums.

  5. Formulation and in vitro evaluation of theophylline anhydrous bioadhesive tablets

    Directory of Open Access Journals (Sweden)

    Deshmukh V

    2009-01-01

    Full Text Available The aim of the current study was to design oral controlled release (CR theophylline anhydrous bioadhesive tablets and to optimize the drug release profile and in vitro bioadhesion strength. Different types of natural hydrophilic polymers such as xanthun gum, locust bean gum, guar gum, karaya gum, and their combinations were used to formulate matrix tablets. Tablets of anhydrous theophylline were prepared by the direct compression method and were subjected to in vitro drug dissolution for 12 hours using the USP dissolution apparatus basket type at a speed of 100 rpm and temperature of 37 ± 0.5°C using gastric fluid (pH 1.2. The bioadhesive strength of the tablets was measured as the force of detachment against the porcine gastric mucosa. The in vitro release study as well as the retention time of the bioadhesive tablets on the mucous membrane were investigated to develop a bioadhesive polymer-based CR delivery system and to evaluate the performance of such a delivery device. The combination of karaya gum:guar gum (6:4 tablet showed a greater bioadhesive strength as compared with a single gum and other gum combination tablets. Karaya gum:guar gum-loaded tablets were not discharged from the mucous membrane and were dissolved in the gastric fluid. An increase in the gum concentration increases the drug release profile beyond 12 hours whereas there is no significant effect of gum concentration on the bioadhesive strength of the tablet.

  6. Properties of gastroretentive sustained release tablets prepared by combination of melt/sublimation actions of L-menthol and penetration of molten polymers into tablets.

    Science.gov (United States)

    Fukuda, Mamoru; Goto, Akinori

    2011-01-01

    A novel floating sustained release tablet having a cavity in the center was developed by utilizing the physicochemical properties of L-menthol and the penetration of molten hydrophobic polymer into tablets. A dry-coated tablet containing famotidine as a model drug in outer layer was prepared with a L-menthol core by direct compression. The tablet was placed in an oven at 80°C to remove the L-menthol core from tablet. The resulting tablet was then immersed in the molten hydrophobic polymers at 90°C. The buoyancy and drug release properties of tablets were investigated using United States Pharmacopeia (USP) 32 Apparatus 2 (paddle 100 rpm) and 900 ml of 0.01 N HCl. The L-menthol core in tablets disappeared completely through pathways in the outer layer with no drug outflows when placed in an oven for 90 min, resulting in a formation of a hollow tablet. The hollow tablets floated on the dissolution media for a short time and the drug release was rapid due to the disintegration of tablet. When the hollow tablets were immersed in molten hydrophobic polymers for 1 min, the rapid drug release was drastically retarded due to a formation of wax matrices within the shell of tablets and the tablets floated on the media for at least 6 h. When Lubri wax® was used as a polymer, the tablets showed the slowest sustained release. On the other hand, faster sustained release properties were obtained by using glyceryl monostearate (GMS) due to its low hydrophobic nature. The results obtained in this study suggested that the drug release rate from floating tablets could be controlled by both the choice of hydrophobic polymer and the combined use of hydrophobic polymers.

  7. Drug release characteristics from chitosan-alginate matrix tablets based on the theory of self-assembled film.

    Science.gov (United States)

    Li, Liang; Wang, Linlin; Shao, Yang; Ni, Rui; Zhang, Tingting; Mao, Shirui

    2013-06-25

    The aim of this study was to better understand the underlying drug release characteristics from chitosan-alginate matrix tablets containing different types of drugs. Theophylline, paracetamol, metformin hydrochloride and trimetazidine hydrochloride were used as model drugs exhibiting significantly different solubilities (12, 16, 346 and >1000 mg/ml at 37 °C in water). A novel concept raised was that drugs were released from chitosan-alginate matrix tablets based on the theory of a self-assembled film-controlled release system. The film was only formed on the surface of tablets in gastrointestinal environment and originated from chitosan-alginate polyelectrolyte complex, confirmed by differential scanning calorimetry characterization. The formed film could decrease the rate of polymer swelling to a degree, also greatly limit the erosion of tablets. Drugs were all released through diffusion in the hydrated matrix and polymer relaxation, irrespective of the drug solubility. The effects of polymer level and initial drug loading on release depended on drug properties. Drug release was influenced by the change of pH. In contrast, the impact of ionic strength of the release medium within the physiological range was negligible. Importantly, hydrodynamic conditions showed a key factor determining the superiority of the self-assembled film in controlling drug release compared with conventional matrix tablets. The new insight into chitosan-alginate matrix tablets can help to broaden the application of this type of dosage forms.

  8. Formulation and Evaluation of Darifenacin Hydrobromide Extended Release Matrix Tablets

    Directory of Open Access Journals (Sweden)

    Syed Meraj Sultana

    2016-08-01

    Full Text Available Darifenacin hydrobromide is a highly selective muscarinic (M3 receptor blocker that has been widely used for the treatment of overactive bladder syndrome. The bioavailability of darifenacin hydrobromide is 15–19% due to extensive first pass metabolism. Hence oral administration of darifenacin hydrobromide as extended tablets is a possible solution to overcome this problem. So the aim of the study was to formulate and evaluate Darifenacin hydrobromide extended release matrix tablets using extended release polymers like HPMC K4M, HPMC K15M and HPMC K100M, Metalose 60 SH-50 and Xanthum gum in different concentrations. Formulated tablets were characterized for different parameters like hardness, thickness, weight variation, friability, % Cumulative drug release etc. Nine formulations (F1 – F9 were formulated using direct compression technique. From the results obtained, it was concluded that the optimized formulation containing HPMC K15 M and K100M (1:2 showed better release up to 24hrs.The dissolution profiles and kinetic studies indicate that the release of Darifenacin Hydrobromide can be effectively controlled by the use of hydrophilic matrix systems. Different kinetic models were applied to the optimized formulation and observed that formulation (F9 followed first order kinetic model and Non-Fickian diffusion (or Anomalous transport as mechanism of drug release.

  9. In-line positioning of ultrasound images using wireless remote display system with tablet computer facilitates ultrasound-guided radial artery catheterization.

    Science.gov (United States)

    Tsuchiya, Masahiko; Mizutani, Koh; Funai, Yusuke; Nakamoto, Tatsuo

    2016-02-01

    Ultrasound-guided procedures may be easier to perform when the operator's eye axis, needle puncture site, and ultrasound image display form a straight line in the puncture direction. However, such methods have not been well tested in clinical settings because that arrangement is often impossible due to limited space in the operating room. We developed a wireless remote display system for ultrasound devices using a tablet computer (iPad Mini), which allows easy display of images at nearly any location chosen by the operator. We hypothesized that the in-line layout of ultrasound images provided by this system would allow for secure and quick catheterization of the radial artery. We enrolled first-year medical interns (n = 20) who had no prior experience with ultrasound-guided radial artery catheterization to perform that using a short-axis out-of-plane approach with two different methods. With the conventional method, only the ultrasound machine placed at the side of the head of the patient across the targeted forearm was utilized. With the tablet method, the ultrasound images were displayed on an iPad Mini positioned on the arm in alignment with the operator's eye axis and needle puncture direction. The success rate and time required for catheterization were compared between the two methods. Success rate was significantly higher (100 vs. 70 %, P = 0.02) and catheterization time significantly shorter (28.5 ± 7.5 vs. 68.2 ± 14.3 s, P method as compared to the conventional method. An ergonomic straight arrangement of the image display is crucial for successful and quick completion of ultrasound-guided arterial catheterization. The present remote display system is a practical method for providing such an arrangement.

  10. Integrating a Single Tablet PC in Chemistry, Engineering, and Physics Courses

    Science.gov (United States)

    Rogers, James W.; Cox, James R.

    2008-01-01

    A tablet PC is a versatile computer that combines the computing power of a notebook with the pen functionality of a PDA (Cox and Rogers 2005b). The authors adopted tablet PC technology in order to improve the process and product of the lecture format in their chemistry, engineering, and physics courses. In this high-tech model, a single tablet PC…

  11. Formulation and in-vitro evaluation of floating bilayer tablet of lisinopril maleate and metoprolol tartrate.

    Science.gov (United States)

    Ijaz, Hira; Qureshi, Junaid; Danish, Zeeshan; Zaman, Muhammad; Abdel-Daim, Mohamed; Hanif, Muhammad; Waheed, Imran; Mohammad, Imran Shair

    2015-11-01

    The purpose of this study was to introduce the technology for the development of rate-controlled oral drug delivery system to overcome various physiological problems. Several approaches are being used for the purpose of increasing the gastric retentive time, including floating drug delivery system. Gastric floating lisinopril maleate and metoprolol tartrate bilayer tablets were formulated by direct compression method using the sodium starch glycolate, crosscarmellose sodium for IR layer. Eudragit L100, pectin, acacia as sustained release polymers in different ratios for SR metoprolol tartrate layer and sodium bicarbonate, citric acid as gas generating agents for the floating extended release layer. The floating bilayer tablets of lisinopril maleate and metoprolol tartrate were designed to overcome the various problems associated with conventional oral dosage form. Floating tablets were evaluated for floating lag time, drug contents and in-vitro dissolution profile and different kinetic release models were applied. It was clear that the different ratios of polymers affected the drug release and floating time. L2 and M4 showed good drug release profile and floating behavior. The linear regression and model fitting showed that all formulation followed Higuchi model of drug release model except M4 that followed zero order kinetic. From the study it is evident that a promising controlled release by floating bilyer tablets of lisinopril maleate and metoprolol tartrate can be developed successfully.

  12. [Modern polymers in matrix tablets technology].

    Science.gov (United States)

    Zimmer, Łukasz; Kasperek, Regina; Poleszak, Ewa

    2014-01-01

    Matrix tablets are the most popular method of oral drug administration, and polymeric materials have been used broadly in matrix formulations to modify and modulate drug release rate. The main goal of the system is to extend drug release profiles to maintain a constant in vivo plasma drug concentration and a consistent pharmacological effect. Polymeric matrix tablets offer a great potential as oral controlled drug delivery systems. Cellulose derivatives, like hydroxypropyl methylcellulose (HPMC) are often used as matrix formers. However, also other types of polymers can be used for this purpose including: Kollidon SR, acrylic acid polymers such as Eudragits and Carbopols. Nevertheless, polymers of natural origin like: carragens, chitosan and alginates widely used in the food and cosmetics industry are now coming to the fore of pharmaceutical research and are used in matrix tablets technology. Modern polymers allow to obtain matrix tablets by 3D printing, which enables to develop new formulation types. In this paper, the polymers used in matrix tablets technology and examples of their applications were described.

  13. Bilayer Tablet via Microsphere: A Review

    Directory of Open Access Journals (Sweden)

    Piyushkumar Vinubhai Gundaraniya

    2013-01-01

    Full Text Available The aim of the present work is to develop bilayer tablets containing sustained release microspheres as one layer and immediate release as another layer. The proposed dosage form is intended to decrease the dosing frequency and the combined administration of an anti-diabetic agent. Several pharmaceutical companies are currently developing bi-layer tablets, for a variety of reasons: patent extension, therapeutic, marketing to name a few. To reduce capital investment, quite often existing but modified tablet presses are used to develop and produce such tablets. One such approach is using microspheres as carriers for drugs also known as micro particles. It is the reliable means to deliver the drug to the target site with specificity, if modified, and to maintain the desired concentration at the site of interest. Microspheres received much attention not only for prolonged release, but also for targeting of anti-diabetic drugs. Bilayer tablet via microsphere is new era for the successful development of controlled release formulation along with various features to provide a way of successful drug delivery system. Especially when in addition high production output is required. An attempt has been made in this review article to introduce the society to the current technological developments in bilayer and floating drug delivery system.

  14. Effect of diluents on tablet integrity and controlled drug release.

    Science.gov (United States)

    Zhang, Y E; Schwartz, J B

    2000-07-01

    The objective of this study was to evaluate the effect of diluents and wax level on tablet integrity during heat treatment and dissolution for sustained-release formulations and the resultant effect on drug release. Dibasic calcium phosphate dihydrate (DCPD), microcrystalline cellulose (MCC), and lactose were evaluated for their effect on tablet integrity during drug dissolution and heat treatment in wax matrix formulations. A newly developed direct compression diluent, dibasic calcium phosphate anhydrous (DCPA), was also evaluated. Compritol 888 ATO was used as the wax matrix material, with phenylpropanolamine hydrochloride (PPA) as a model drug. Tablets were made by direct compression and then subjected to heat treatment at 80 degrees C for 30 min. The results showed that MCC, lactose, and DCPA could maintain tablets intact during heat treatment above the melting point of wax (70 degrees C-75 degrees C). However, DCPD tablets showed wax egress during the treatment. MCC tablets swelled and cracked during drug dissolution and resulted in quick release. DCPD and lactose tablets remained intact during dissolution and gave slower release than MCC tablets. DCPA tablets without heat treatment disintegrated very quickly and showed immediate release. In contrast, heat-treated DCPA tablets remained intact through the 24-hr dissolution test and only released about 80% PPA at 6 hr. In the investigation of wax level, DCPD was used as the diluent. The drug release rate decreased as the wax content increased from 15% to 81.25%. The dissolution data were best described by the Higuchi square-root-of-time model. Diluents showed various effects during heat treatment and drug dissolution. The integrity of the tablets was related to the drug release rate. Heat treatment retarded drug release if there was no wax egress.

  15. Determining the polymer threshold amount for achieving robust drug release from HPMC and HPC matrix tablets containing a high-dose BCS class I model drug: in vitro and in vivo studies.

    Science.gov (United States)

    Klančar, Uroš; Baumgartner, Saša; Legen, Igor; Smrdel, Polona; Kampuš, Nataša Jeraj; Krajcar, Dejan; Markun, Boštjan; Kočevar, Klemen

    2015-04-01

    It is challenging to achieve mechanically robust drug-release profiles from hydrophilic matrices containing a high dose of a drug with good solubility. However, a mechanically robust drug release over prolonged period of time can be achieved, especially if the viscosity and amount of the polymer is sufficiently high, above the "threshold values." The goal of this research was to determine the hydroxypropyl cellulose (HPC) and hydroxypropyl methylcellulose (HPMC) polymer threshold amount that would enable robust drug release from matrix tablets containing a high dose of levetiracetam as a class I model drug according to the Biopharmaceutical Classification System (BCS). For this purpose, formulations containing HPC or HPMC of similar viscosity range, but in different amounts, were prepared. Based on the dissolution results, two final formulations were selected for additional in vitro and in vivo evaluation to confirm the robustness and to show bioequivalence. Tablets were exposed to various stress conditions in vitro with the use of different mechanically stress-inducing dissolution methods. The in vitro results were compared with in vivo results obtained from fasted and fed bioequivalence studies. Under both conditions, the formulations were bioequivalent and food had a negligible influence on the pharmacokinetic parameters C max and area under the curve (AUC). It was concluded that the drug release from both selected formulations is mechanically robust and that HPC and HPMC polymers with intrinsic viscosities above 9 dL/g and in quantities above 30% enable good mechanical resistance, which ensures bioequivalence. In addition, HPC matrices were found to be more mechanically robust compared to HPMC.

  16. Preparation and in vitro evaluation of guar gum based triple-layer matrix tablet of diclofenac sodium.

    Science.gov (United States)

    Chavda, H V; Patel, M S; Patel, C N

    2012-01-01

    The objective of the present study was to design an oral controlled drug delivery system for sparingly soluble diclofenac sodium (DCL) using guar gum as triple-layer matrix tablets. Matrix tablet granules containing 30% (D1), 40% (D2) or 50% (D3) of guar gum were prepared by the conventional wet granulation technique. Matrix tablets of diclofenac sodium were prepared by compressing three layers one by one. Centre layer of sandwich like structure was incorporated with matrix granules containing DCL which was covered on either side by guar gum granule layers containing either 70, 80 or 87% of guar gum as release retardant layers. The tablets were evaluated for hardness, thickness, drug content, and drug release studies. To ascertain the kinetics of drug release, the dissolution profiles were fitted to various mathematical models. The in vitro drug release from proposed system was best explained by the Hopfenberg model indicating that the release of drug from tablets displayed heterogeneous erosion. D3G3, containing 87% of guar gum in guar gum layers and 50% of guar gum in DCL matrix granule layer was found to provide the release rate for prolonged period of time. The results clearly indicate that guar gum could be a potential hydrophilic carrier in the development of oral controlled drug delivery systems.

  17. Evaluation of Calendula mucilage as a mucoadhesive and controlled release component in buccal tablets.

    Science.gov (United States)

    Sabale, V; Patel, V; Paranjape, A

    2014-01-01

    Mucoadhesive drug delivery systems were developed to sustain drug delivery via various mucus membranes for either local or systemic delivery of poorly absorbed drugs such as peptides and proteins as well as drugs that are subjected to high first-pass metabolism. The present study was undertaken to use isolated Calendula mucilage as a mucoadhesive agent and to formulate controlled release buccoadhesive tablets with an intention to avoid hepatic first-pass metabolism as well as to enhance residence time of drug in the buccal cavity. The mucilage was isolated from the Calendula petals by aqueous extraction method and characterized for various physiochemical parameters as well as for its adhesive properties. By using direct compression technique, tablets were prepared containing dried mucilage and chlorpheniramine maleate (CPM) as a model drug. Three batches of tablets were prepared and evaluated containing three mucoadhesive components namely Methocel K4M, Carbopol 974P and isolated Calendula mucilage in 16.66%, 33.33 % and 50 % (1:2:3 ratio) resulting in 9 different formulations. FTIR studies between mucilage and CPM suggested the absence of a chemical interaction between CPM and Calendula mucilage. The results of the study showed that the isolated mucilage had good physicochemical and morphological characteristics and tablets conformed to the pharmacopoeial specifications. Also in vitro release studies showed controlled action of drug with increasing the concentration of the isolated Calendula mucilage as a mucoadhesive agent in the formulations. Permeability studies indicated that permeability behavior was not statistically different (P>0.05) by changing the mucoadhesive component. The formulated mucoadhesive tablets for buccal administration containing 75 mg Calendula mucilage showed controlled drug release. Thus, mucoadhesive natural Calendula mucilage based buccal tablets for controlled release were successfully formulated.

  18. Hydroxypropyl methylcellulose based cephalexin extended release tablets: influence of tablet formulation, hardness and storage on in vitro release kinetics.

    Science.gov (United States)

    Saravanan, Muniyandy; Sri Nataraj, Kalakonda; Ganesh, Kettavarampalayam Swaminath

    2003-08-01

    The object of this study was to develop hydroxypropyl methylcellulose (HPMC) based cephalexin extended release tablet, which can release the drug for six hours in predetermined rate. Twenty-one batches of cephalexin tablets were prepared by changing various physical and chemical parameters, in order to get required theoretical release profile. The influences of HPMC, microcrystalline cellulose powder (MCCP), granulation technique, wetting agent and tablet hardness on cephalexin release from HPMC based extended release tablets were studied. The formulated tablets were also characterized by physical and chemical parameters. The dissolution results showed that a higher amount of HPMC in tablet composition resulted in reduced drug release. Addition of MCCP resulted in faster drug release. Tablets prepared by dry granulation was released the drug slowly than the same prepared with a wet granulation technique. Addition of wetting agent in the tablets prepared with dry granulation technique showed slower release. An increase in tablet hardness resulted in faster drug release. Tablets prepared with a wet granulation technique and having a composition of 9.3% w/w HPMC with a hardness of 10-12 kg/cm(2) gave predicted release for 6 h. The in vitro release data was well fit in to Higuchi and Korsmeyer-Peppas model. Physical and chemical parameters of all formulated tablets were within acceptable limits. One batch among formulated twenty-one batches was successful and showed required theoretical release. The effect of storage on in vitro release and physicochemical parameters of successful batch was studied and was found to be in acceptable limits.

  19. Tablet PC Support of Students' Learning Styles

    Directory of Open Access Journals (Sweden)

    Shreya Kothaneth

    2012-12-01

    Full Text Available In the context of rapid technology development, it comes as no surprise that technology continues to impact the educational domain, challenging traditional teaching and learning styles. This study focuses on how students with different learning styles use instructional technology, and in particular, the tablet PC, to enhance their learning experience. The VARK model was chosen as our theoretical framework as we analyzed responses of an online survey, both from a quantitative and qualitative standpoint. Results indicate that if used correctly, the tablet PC can be used across different learning styles to enrich the educational experience.

  20. Distribution of crushing strength of tablets

    DEFF Research Database (Denmark)

    Sonnergaard, Jørn

    2002-01-01

    as a material constant. However, the estimation of this parameter is laborious and subject to estimation problems. It is shown that the Weibull modulus is inherently connected to the coefficient of variation and that the information obtained from the modulus is unclear. The distribution of crushing strength...... data from nine model tablet formulations and four commercial tablets are shown to follow the normal distribution. The importance of proper cleaning of the crushing strength apparatus is demonstrated. Copyright © 2002 Elsevier Science B.V....

  1. Tablet PC Support of Students' Learning Styles

    Directory of Open Access Journals (Sweden)

    Shreya Kothaneth

    2012-12-01

    Full Text Available In the context of rapid technology development, it comes as no surprise that technology continues to impact the educational domain, challenging traditional teaching and learning styles. This study focuses on how students with different learning styles use instructional technology, and in particular, the tablet PC, to enhance their learning experience. The VARK model was chosen as our theoretical framework as we analyzed responses of an online survey, both from a quantitative and qualitative standpoint. Results indicate that if used correctly, the tablet PC can be used across different learning styles to enrich the educational experience.

  2. Teach yourself visually Fire tablets

    CERN Document Server

    Marmel, Elaine

    2014-01-01

    Expert visual guidance to getting the most out of your Fire tablet Teach Yourself VISUALLY Fire Tablets is the comprehensive guide to getting the most out of your new Fire tablet. Learn to find and read new bestsellers through the Kindle app, browse the app store to find top games, surf the web, send e-mail, shop online, and much more! With expert guidance laid out in a highly visual style, this book is perfect for those new to the Fire tablet, providing all the information you need to get the most out of your device. Abundant screenshots of the Fire tablet graphically rich, touch-based Androi

  3. A three-layer guar gum matrix tablet for oral controlled delivery of highly soluble metoprolol tartrate.

    Science.gov (United States)

    Krishnaiah, Y S R; Karthikeyan, R S; Satyanarayana, V

    2002-07-25

    The objective of the study is to design oral controlled drug delivery systems for highly water-soluble drugs using guar gum as a carrier in the form of a three-layer matrix tablet. Metoprolol tartrate was chosen as a model drug because of its high water solubility. Matrix tablets containing either 30 (M1), 40 (M2) or 50% (M3) of guar gum were prepared by wet granulation technique using starch paste as a binder. Three-layer matrix tablets of metoprolol tartrate were prepared by compressing on both sides of guar gum matrix tablet granules of metoprolol tartrate M1, M2 or M3 with either 50 (TL1M1, TL1M2 or TL1M3) or 75 mg (TL2M1, TL2M2 or TL2M3) of guar gum granules as release retardant layers. Both the matrix and three-layer matrix tablets were evaluated for hardness, thickness, drug content uniformity, and subjected to in vitro drug release studies. The amount of metoprolol tartrate released from the matrix and three-layer matrix tablets at different time intervals was estimated by using a HPLC method. Matrix tablets of metoprolol tartrate were unable to provide the required drug release rate. However, the three-layer guar gum matrix tablets (TL2M3) provided the required release rate on par with the theoretical release rate for metoprolol tartrate formulations meant for twice daily administration. The three-layer guar gum matrix tablet (TL2M3) showed no change either in physical appearance, drug content or in dissolution pattern after storage at 40 degrees C/75% RH for 6 months. The FT-IR study did not show any possibility of metoprolol tartrate/guar gum interaction with the formulation excipients used in the study. The results indicated that guar gum, in the form of three-layer matrix tablets, is a potential carrier in the design of oral controlled drug delivery systems for highly water-soluble drugs such as metoprolol tartrate.

  4. Comparative studies on the dissolution profiles of oral ibuprofen suspension and commercial tablets using biopharmaceutical classification system criteria

    Directory of Open Access Journals (Sweden)

    J C Rivera-Leyva

    2012-01-01

    Full Text Available In vitro dissolution studies for solid oral dosage forms have recently widened the scope to a variety of special dosage forms such as suspensions. For class II drugs, like Ibuprofen, it is very important to have discriminative methods for different formulations in physiological conditions of the gastrointestinal tract, which will identify different problems that compromise the drug bioavailability. In the present work, two agitation speeds have been performed in order to study ibuprofen suspension dissolution. The suspensions have been characterised relatively to particle size, density and solubility. The dissolution study was conducted using the following media: buffer pH 7.2, pH 6.8, 4.5 and 0.1 M HCl. For quantitative analysis, the UV/Vis spectrophotometry was used because this methodology had been adequately validated. The results show that 50 rpm was the adequate condition to discriminate the dissolution profile. The suspension kinetic release was found to be dependent on pH and was different compared to tablet release profile at the same experimental conditions. The ibuprofen release at pH 1.0 was the slowest.

  5. Preparation and evaluation of novel metronidazole sustained release and floating matrix tablets.

    Science.gov (United States)

    Asnaashari, Solmaz; Khoei, Nazaninossadat Seyed; Zarrintan, Mohammad Hosein; Adibkia, Khosro; Javadzadeh, Yousef

    2011-08-01

    In the present study, metronidazole was used for preparing floating dosage forms that are designed to retain in the stomach for a long time and have developed as a drug delivery system for better eradication of Helicobacter Pylori in peptic ulcer diseases. For this means, various formulations were designed using multi-factorial design. HPMC, psyllium and carbopol in different concentrations were used as floating agents, and sodium bicarbonate was added as a gas-forming agent. Hardness, friability, drug loading, floating ability and release profiles as well as kinetics of release were assessed. Formulations containing HPMC as filler showed prolonged lag times for buoyancy. Adding psyllium to these formulations had reduced relative lag times. Overall, selected formulations were able to float immediately and showed buoyancy for at least 8?h. Meanwhile, sustained profiles of drug release were also obtained. Kinetically, among the 10 assessed models, the release pattern of metronidazole from the tablets fitted best to Power law, Weibull and Higuchi models in respect overall to mean percentage error values of 3.8, 4.73 and 5.77, respectively, for calcium carbonate-based tablets and, 2.95, 6.39 and 3.9, respectively, for calcium silicate-based tablets. In general, these systems can float in the gastric condition and control the drug release from the tablets.

  6. Modelling Railway Interlocking Systems

    DEFF Research Database (Denmark)

    Lindegaard, Morten Peter; Viuf, P.; Haxthausen, Anne Elisabeth

    2000-01-01

    In this report we present a model of interlocking systems, and describe how the model may be validated by simulation. Station topologies are modelled by graphs in which the nodes denote track segments, and the edges denote connectivity for train traÆc. Points and signals are modelled by annotatio...

  7. The Nebusarsekim Tablet

    NARCIS (Netherlands)

    Stadhouders, H.A.I.

    2008-01-01

    During the summer of 2007 an internet hype was unleashed by the breaking news that an Old Testament name of some importance, figuring in the Book of Jeremiah Ch. 39, had been positively identified on a cuneiform clay tablet, viz. a bill of receipt from the time of this prophet's floruit. Many a scho

  8. Development and evaluation of Ketoprofen sustained release matrix tablet using Hibiscus rosa-sinensis leaves mucilage

    Directory of Open Access Journals (Sweden)

    M. Kaleemullah

    2017-07-01

    Full Text Available Currently, the use of natural gums and mucilage is of increasing importance in pharmaceutical formulations as valuable drug excipient. Natural plant-based materials are economic, free of side effects, biocompatible and biodegradable. Therefore, Ketoprofen matrix tablets were formulated by employing Hibiscus rosa-sinensis leaves mucilage as natural polymer and HPMC (K100M as a synthetic polymer to sustain the drug release from matrix system. Direct compression method was used to develop sustained released matrix tablets. The formulated matrix tablets were evaluated in terms of physical appearance, weight variation, thickness, diameter, hardness, friability and in vitro drug release. The difference between the natural and synthetic polymers was investigated concurrently. Matrix tablets developed from each formulation passed all standard physical evaluation tests. The dissolution studies of formulated tablets revealed sustained drug release up to 24 h compared to the reference drug Apo Keto® SR tablets. The dissolution data later were fitted into kinetic models such as zero order equation, first order equation, Higuchi equation, Hixson Crowell equation and Korsmeyer-Peppas equation to study the release of drugs from each formulation. The best formulations were selected based on the similarity factor (f2 value of 50% and more. Through the research, it is found that by increasing the polymers concentration, the rate of drug release decreased for both natural and synthetic polymers. The best formulation was found to be F3 which contained 40% Hibiscus rosa-sinensis mucilage polymer and showed comparable dissolution profile to the reference drug with f2 value of 78.03%. The release kinetics of this formulation has shown to follow non-Fickian type which involved both diffusion and erosion mechanism. Additionally, the statistical results indicated that there was no significant difference (p > 0.05 between the F3 and reference drug in terms of MDT and

  9. A Systems Biology-Based Approach to Uncovering the Molecular Mechanisms Underlying the Effects of Dragon's Blood Tablet in Colitis, Involving the Integration of Chemical Analysis, ADME Prediction, and Network Pharmacology

    OpenAIRE

    Haiyu Xu; Yanqiong Zhang; Yun Lei; Xiumei Gao; Huaqiang Zhai; Na Lin; Shihuan Tang; Rixin Liang; Yan Ma; Defeng Li; Yi Zhang; Guangrong Zhu; Hongjun Yang; Luqi Huang

    2014-01-01

    Traditional Chinese medicine (TCM) is one of the oldest East Asian medical systems. The present study adopted a systems biology-based approach to provide new insights relating to the active constituents and molecular mechanisms underlying the effects of dragon's blood (DB) tablets for the treatment of colitis. This study integrated chemical analysis, prediction of absorption, distribution, metabolism, and excretion (ADME), and network pharmacology. Firstly, a rapid, reliable, and accurate ult...

  10. Gastroretentive Pulsatile Release Tablets of Lercanidipine HCl: Development, Statistical Optimization, and In Vitro and In Vivo Evaluation

    Directory of Open Access Journals (Sweden)

    Gagganapalli Santhoshi Reddy

    2014-01-01

    Full Text Available The present study was aimed at the development of gastroretentive floating pulsatile release tablets (FPRTs of lercanidipine HCl to enhance the bioavailability and treat early morning surge in blood pressure. Immediate release core tablets containing lercanidipine HCl were prepared and optimized core tablets were compression-coated using buoyant layer containing polyethylene oxide (PEO WSR coagulant, sodium bicarbonate, and directly compressible lactose. FPRTs were evaluated for various in vitro physicochemical parameters, drug-excipient compatibility, buoyancy, swelling, and release studies. The optimized FPRTs were tested in vivo in New Zealand white rabbits for buoyancy and pharmacokinetics. DoE optimization of data revealed FPRTs containing PEO (20% w/w with coat weight 480 mg were promising systems exhibiting good floating behavior and lag time in drug release. Abdominal X-ray imaging of rabbits after oral administration of the tablets, confirmed the floating behavior and lag time. A quadratic model was suggested for release at 7th and 12th h and a linear model was suggested for release lag time. The FPRT formulation improved pharmacokinetic parameters compared to immediate release tablet formulation in terms of extent of absorption in rabbits. As the formulation showed delay in drug release both in vitro and in vivo, nighttime administration could be beneficial to reduce the cardiovascular complications due to early morning surge in blood pressure.

  11. Home healthcare monitoring embedded system based on tablet PC%基于平板电脑的家庭医疗监护系统

    Institute of Scientific and Technical Information of China (English)

    杨鹏; 王文俊

    2012-01-01

    以基于WindowsCE的平板电脑为硬件开发平台,采用VS2005集成开发环境开发了基于WindowsCE操作系统的USB驱动和基于WindowsCE系统的生理参数监护图形界面软件,并利用平板电脑常见的USB接口作为数据传输接口与生理参数采集模块进行数据通信,以对人体的主要生理参数进行实时监控。经试验显示,该监护系统基本达到了预期的要求。%The system is based on the hardware platform of tablet PC based on Windows CE. The USB driver and graphical interface software of physiological parameter monitoring based on Windows CE is developed with VS2005 integrated development environment tool.The system communicates with the physiological parameters acquisition module with USB interface in order to monitor the mainly physiological parameters on the human body. Experiment shows the monitoring system can meet desired real-time monitoring request.

  12. Optimization and Assessment of Three Different High Performance Liquid Chromatographic Systems for the Combinative Fingerprint Analysis and Multi-Ingredients Quantification of Sangju Ganmao Tablet.

    Science.gov (United States)

    Guo, Meng-Zhe; Han, Jie; He, Dan-Dan; Zou, Jia-Hui; Li, Zheng; Du, Yan; Tang, Dao-Quan

    2017-03-01

    Chromatographic separation is still a critical subject for the quality control of traditional Chinese medicine. In this study, three different high performance liquid chromatographic (HPLC) systems employing commercially available columns packed with 1.8, 3.5 and 5.0 μm particles were respectively developed and optimized for the combinative fingerprint analysis and multi-ingredients quantification of Sangju Ganmao tablet (SGT). Chromatographic parameters including the repeatability of retention time and peak area, symmetry factor, resolution, number of theoretical plates and peak capacity were used to assess the chromatographic performance of different HPLC systems. The optimal chromatographic system using Agilent ZORBAX SB-C18 column (2.1 mm × 100 mm, 3.5 μm) as stationary phase was respectively coupled with diode array detector or mass spectrometry detector for the chromatographic fingerprint analysis and simultaneous quantification or identification of nine compounds of SGT. All the validation data conformed to the acceptable requirements. For the fingerprint analysis, 31 peaks were selected as the common peaks to evaluate the similarities of SGT from 10 different manufacturers using heatmap, hierarchical cluster analysis and principal component analysis. The results demonstrated that the combinations of the quantitative and chromatographic fingerprint analysis offer an efficient way to evaluate the quality consistency of SGT.

  13. A binary concrete crack self-healing system containing oxygen-releasing tablet and bacteria and its Ca(2+)-precipitation performance.

    Science.gov (United States)

    Zhang, J L; Wang, C G; Wang, Q L; Feng, J L; Pan, W; Zheng, X C; Liu, B; Han, N X; Xing, F; Deng, X

    2016-12-01

    A strategy to supply molecular oxygen for microbial calcium precipitation was developed for the first time. Firstly, a controlled oxygen-releasing tablet (ORT) containing CaO2 and lactic acid with a suitable ratio of 9:1 was developed. It can provide a stable oxygen supply and maintain pH in the range of 9.5-11.0 for 45 days while contacting with water. In the presence of oxygen, a self-healing bacterium H4 spores germinated more effectively and maintained high metabolic activity. Furthermore, H4 vegetative cells induced 50 % more calcium precipitation than that obtained without oxygen supply. Finally, a binary self-healing system containing bacterial spores and ORT was established. The calcium precipitation experiments showed that H4 in the binary self-healing system precipitated 27.5 mM calcium with oxygen supply after 32 days and dissolved oxygen (DO) concentration of the solution decreased from 15 to 4 mg l(-1), while only 6.9 mM calcium precipitation was obtained without oxygen supply. This work can disclose the effect of oxygen on microbial calcium precipitation and further lay a foundation for the establishment of ternary self-healing system containing bacteria, ORT, and nutrients, which will be promising for the self-healing of cracks deep inside the concrete structure.

  14. In-process control data acquisition and analysis in tablet production

    OpenAIRE

    Hribar , Erik

    2012-01-01

    The diploma thesis will study the problem of process data acquisition and analysis. It describes the upgrade of current information system for in-process control in tablet production. We will establish the system for overview and archiving of measurements from tableting machine control unit. We will prepare various statistical views for comparison of data from current system and archived measurements from tableting machine control unit. Current information system for in-process control maint...

  15. Enhancement of famotidine dissolution rate through liquisolid tablets formulation: in vitro and in vivo evaluation.

    Science.gov (United States)

    Fahmy, Rania H; Kassem, Mohammed A

    2008-08-01

    Although famotidine was reported to be 7.5 and 20 times more potent than ranitidine and cimetidine, respectively, its oral bioavailability is low and variable; due mainly to its poor aqueous solubility. The purpose of this study was to improve famotidine dissolution through its formulation into liquisolid systems and then to investigate the in vitro and in vivo performance of the prepared liquisolid tablets. The new mathematical model was utilized to formulate various liquisolid powder systems. Both DSC and XRD suggested loss of famotidine crystallinity upon liquisolid formulation which was further confirmed by SEM indicating that even though the drug existed in a solid dosage form, it is held within the powder substrate in a solubilized, almost molecularly dispersed state, which contributed to the enhanced drug dissolution properties. All the tested liquisolid tablet formulations showed higher drug dissolution rates (DR) than the conventional, directly compressed tables. In addition, the selected optimal formula released 78.36% of its content during the first 10 min which is 39% higher than that of the directly compressed tablets. Further, the bioavailability study indicated that the prepared optimal liquisolid formula did not differ significantly from the marketed famotidine tablets concerning Cmax, tmax, and AUC(0-8) at P<0.05.

  16. Tablet Computer Literacy Levels of the Physical Education and Sports Department Students

    Directory of Open Access Journals (Sweden)

    Gulten HERGUNER

    2016-04-01

    Full Text Available Education systems are being affected in parallel by newly emerging hardware and new developments    occurring in technology daily. Tablet usage especially is becoming ubiquitous in the teaching‐learning processes in recent years. Therefore, using the tablets effectively, managing them and having a high level of tablet literacy play an important role within the education system. This study aimed at determining the tablet literacy levels of students in the Physical Education and Sports Teaching department at Sakarya University in Turkey, and examining this data with regard to various variables. Some 276 students participated in the study. Findings of the study suggest that the sample has a high tablet literacy level. While no significant difference was found in the tablet literacy  by gender, the students in the 2nd grade are noted to have higher levels of tablet literacy compared to the students in 3rd and 4th grades and tablet owners are more tablet literate when compared to non‐owners. A significant but low level correlation was found between the tablet usage time and tablet literacy.  

  17. The effect of Qingbi Tablet on the KLF6-FRP regulation system of rheumatoid arthritis process%清痹片对类风湿关节炎KLF6-FRP调控体系的干预作用

    Institute of Scientific and Technical Information of China (English)

    刘维; 吴沅皞; 刘晓亚; 张磊; 薛斌; 陈英俊

    2011-01-01

    Objective: The project intends to investigate the role of KLF6-FRP regulation system of rheumatoid arthritis process, then to illuminate the possible ati-arthritis mechanism of the Qingbi Tablet, as a scientific basis for the research and application of the antiarthritic traditional Chinese medicine. Methods: Focusing on the Qingbi tablet with the formulating principle of dispelling toxins and dredging collaterals, under the guidance of TCM theory, the experimental research used collagen-induced arthritis (CIA) as the experimental animal models with the incisiveness point of the KLF6-TGFpl-FRP network (Kruppel like transcription factor 6-Transforming growth factor β1-Follistatin related protein). Comparating with normal group, the CIA rats were divided randomly into 5 groups, treating with or without the Qingbi tablets of low, middle, high dosage (0.36gkg -1-d-1, lg-kg-1-d-1 or 1.8g-kg-1-d-1) or Methotrexate. One half of rats were sacrificed on the 35th or the 49th day. The wrist joints were collected for measuring the KLF6 and FRP by Western Blotting. And the ankle joints were collected for measuring the TGFβ1, TNFα, IL-1β and MMP-3 with the immunohistochemistry assay. Results: The expression levels of KLF6, FRP, TGFβ1, TNFα, IL-ip, MMP-3 of CIA in rats were higher significantly compared with the normal ones (P<0.01). With a dose dependent, the expressions of KLF6 in the rats treating with Qingbi tablets of lg-kg-1-d-1 or 1.8g-kg-1-d-1 were lower significantly compared with the model group but of FRP are higher (P<0.01). The expression levels of TGFpi, TNFα, IL-1β, MMP-3 in treated groups are significantly lower than the model group (P<0.01). The expression levels of TNFα, IL-1β, MMP-3 of Qingbi high dosage group were power than the MTX group (P<0.01). Conclusion: The Qingbi Tablet has the effects of intervening the expression the KLF6-FRP regulation system and related factors on the RA process effectively.%目的:探讨清痹片对KLF6-FRP调控体系

  18. Numerical Investigation of the Residual Stress Distribution of Flat-Faced and Convexly Curved Tablets Using the Finite Element Method.

    Science.gov (United States)

    Otoguro, Saori; Hayashi, Yoshihiro; Miura, Takahiro; Uehara, Naoto; Utsumi, Shunichi; Onuki, Yoshinori; Obata, Yasuko; Takayama, Kozo

    2015-01-01

    The stress distribution of tablets after compression was simulated using a finite element method, where the powder was defined by the Drucker-Prager cap model. The effect of tablet shape, identified by the surface curvature, on the residual stress distribution was investigated. In flat-faced tablets, weak positive shear stress remained from the top and bottom die walls toward the center of the tablet. In the case of the convexly curved tablet, strong positive shear stress remained on the upper side and in the intermediate part between the die wall and the center of the tablet. In the case of x-axial stress, negative values were observed for all tablets, suggesting that the x-axial force always acts from the die wall toward the center of the tablet. In the flat tablet, negative x-axial stress remained from the upper edge to the center bottom. The x-axial stress distribution differed between the flat and convexly curved tablets. Weak stress remained in the y-axial direction of the flat tablet, whereas an upward force remained at the center of the convexly curved tablet. By employing multiple linear regression analysis, the mechanical properties of the tablets were predicted accurately as functions of their residual stress distribution. However, the multiple linear regression prediction of the dissolution parameters of acetaminophen, used here as a model drug, was limited, suggesting that the dissolution of active ingredients is not a simple process; further investigation is needed to enable accurate predictions of dissolution parameters.

  19. Suppressed Release of Clarithromycin from Tablets by Crystalline Phase Transition of Metastable Polymorph Form I.

    Science.gov (United States)

    Fujiki, Sadahiro; Watanabe, Narumi; Iwao, Yasunori; Noguchi, Shuji; Mizoguchi, Midori; Iwamura, Takeru; Itai, Shigeru

    2015-08-01

    The pharmaceutical properties of clarithromycin (CAM) tablets containing the metastable form I of crystalline CAM were investigated. Although the dissolution rate of form I was higher than that of stable form II, the release of CAM from form I tablet was delayed. Disintegration test and liquid penetration test showed that the disintegration of the tablet delayed because of the slow penetration of an external solution into form I tablet. Investigation by scanning electron microscopy revealed that the surface of form I tablet was covered with fine needle-shaped crystals following an exposure to the external solution. These crystals were identified as form IV crystals by powder X-ray diffraction. The phenomenon that CAM releases from tablet was inhibited by fine crystals spontaneously formed on the tablet surface could be applied to the design of sustained-release formulation systems with high CAM contents by minimizing the amount of functional excipients. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. Selected System Models

    Science.gov (United States)

    Schmidt-Eisenlohr, F.; Puñal, O.; Klagges, K.; Kirsche, M.

    Apart from the general issue of modeling the channel, the PHY and the MAC of wireless networks, there are specific modeling assumptions that are considered for different systems. In this chapter we consider three specific wireless standards and highlight modeling options for them. These are IEEE 802.11 (as example for wireless local area networks), IEEE 802.16 (as example for wireless metropolitan networks) and IEEE 802.15 (as example for body area networks). Each section on these three systems discusses also at the end a set of model implementations that are available today.

  1. 养心开郁片对抑郁症模型大鼠行为活动的影响%Effect of Yangxin Kaiyu Tablet on Depression Model Rats

    Institute of Scientific and Technical Information of China (English)

    王晓燕; 孙建宁; 林海; 董力; 畅洪异; 王静怡

    2011-01-01

    Objective; To investigate the effect of Yangxin Kaiyu tablet (YXKY Tablet) on behavior and memory in chronic depression model rats. Method:Chronic stress depression rat model was established by chronic and mild unpredictable stressors and housed seperately as described in the literature. The preference for 1 % sucrose solution, Morris water maze and space search test was carried out. SD rats were randomly divided into control group, model group, fluoxetine hydrochloride group, and three dose groups of YXKY tablet (1 500, 750, 375 mg·kg-1). YXKY tablet were administered i. g. once per day for 28 days; same volume of water was given to model group and control group. Result; The preference for 1% sucrose solution was increased in 375, 750 mg·kg-1 of YXKY tablet groups. Navigation latency in Morris water maze was shortened in three dose groups of YXKY tablet. Lasting time, distance, and total times of crossing the target region in the fourth quadrant were increased significantly in 375, 750 mg-kg-1 of YXKY tablet groups. There was statistically significant difference between medication treatment groups and model groups (P <0. 05 or P <0. 01). Conclusion; YXKY tablet could improve depressive rats' behavior and memory. The experimental result provided a basis for clinical treatment to depression.%目的:探讨养心开郁片对抑郁症模型大鼠行为活动和学习记忆的影响.方法:造模方法为慢性轻度不可预见性的应激模型加孤养,观察对大鼠1%蔗糖偏嗜度、Morris水迷宫实验完成的影响.将SD大鼠随机分成6组,即空白对照组、模型组、盐酸氟西汀组、养心开郁片高、中、低剂量组(1 500,750,375 mg· kg-1).造模同时ig给药,每日1次,连续给药28 d.均按10.0 mL·kg-1给药,对照组、模型组ig等量蒸馏水.结果:养心开郁片中、低剂量组均能增加1%蔗糖水偏嗜度;高、中、低剂量组均能缩短Morris水迷宫中定位导航的潜伏期;中、低剂量

  2. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  3. Formulation and optimization of carbamazepine floating tablets

    Directory of Open Access Journals (Sweden)

    Patel D

    2007-01-01

    Full Text Available Floating tablets of carbamazepine were developed using melt granulation technique. Bees wax was used as a hydrophobic meltable material. Hydroxypropylmethylcellulose, sodium bicarbonate and ethyl cellulose were used as matrixing agent, gas-generating agent and floating enhancer, respectively. The tablets were evaluated for in vitro buoyancy and dissolution studies. A simplex lattice design was applied to investigate the combined effect of 3 formulation variables i.e. amount of hydroxypropyl methylcellulose ( X 1 , ethyl cellulose ( X 2 and sodium bicarbonate ( X 3 . The floating lag time (F lag , time required for 50% (t 50 and 80% drug dissolution (t 80 were taken as responses. Results of multiple regression analysis indicated that, low level of X 1 and X 2 , and high level of X 3 should be used to manufacture the tablet formulation with desired in vitro floating time and dissolution. Formulations developed using simplex lattice design were fitted to various kinetic models for drug release. Formulation S3 was selected as a promising formulation and was found stable at 40 o and 75% relative humidity for 3 months. Present study demonstrates the use of simplex lattice design in the development of floating tablets with minimum experimentation.

  4. Multiscale Cloud System Modeling

    Science.gov (United States)

    Tao, Wei-Kuo; Moncrieff, Mitchell W.

    2009-01-01

    The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.

  5. Formulation and evaluation of buccoadhesive tablets of clotrimazole

    Directory of Open Access Journals (Sweden)

    Reza Tahvilian

    2010-01-01

    Full Text Available The buccoadhesive tablet is one of delivery systems that can be used for different drugs in order to improve the efficacy of drugs in patients. Hydrophilic polymers are using to prepare these types of tablets with appropriate adhesion and stability in order to deliver the drug for a period of time and also in a specific place in month. The purpose of the study was to formulate and evaluate mucoadhesive buccal tablets of clotrimazole. The tablets were evaluated for weight variation, hardness, friability, disintegration, content uniformity, surface pH, mucoadhesive strength, swelling index and in vitro drug release.Increasing hydroxypropylmethylcellulose (HPMC concentration resulted in decreasing the swelling index and increasing surface pH. The surface pH of all tablets was found to be satisfactory, close to neutral pH; hence, no irritation would observe with these tablets. The maximum bioadhesive strength was observed in tablets formulated with high content of HPMC. Lower release rates were observed by increasing the content of HPMC in the formulation The in vitro release results demonstrated that drug is released by non-Fickian diffusion mechanism with zero-order kinetics.

  6. FORMULATION DEVELOPMENT AND EVALUATION OF TERBUTALINE SULPHATE MUCOADHESIVE BUCCAL TABLETS

    Directory of Open Access Journals (Sweden)

    Gururaj S.Kulkarni

    2013-03-01

    Full Text Available The main objective of developing any new dosage form is reduce the side effects and increase the therapeutic effect of drug in existing dose of dosage form. Mucoadhesive drug delivery system is oral dosage form, where the tablet, gel or patch is attached to the buccal region for direct absorption of drug into blood circulation. This route can prevent the metabolism of drug in G.I tract or liver and side effects of metabolites avoided. In this study, the attempt was made to prepare mucoadhesive buccal tablets of Terbutaline sulphate with natural polymer sodium alginate with one side absorption by backing layer with ethyl cellulose. The buccal tablets of Terbutaline sulphate studied in detail. I R Spectroscopy did the compatible study between polymers and Terbutaline sulphate and No interaction was found between drug and polymers. Different formulations of oral Mucoadhesive buccal tablets of Terbutaline Sulphate (TS were prepared using polymer sodium alginate, in different concentrations by direct compression. Post compressed evaluation studies, hardness, thickness, friability; weight variation and drug content, mucoadhesive strength of tablets were studied. The in-vitro release of TS was studied in buffer pH 6.8 at 370C. All parameters of TS buccal tablets are passed the standard of mucoadhesive buccal tablets. It was found that mucoadhesive natural polymers exhibited better adhesiveness and mucoadhesiveness. The in vitro study of TS exhibited greater drug release profile with release of in the range of 79.25 to 99.85%.

  7. Dynamic Systems Modeling

    Directory of Open Access Journals (Sweden)

    Sorin Dan ŞANDOR

    2003-01-01

    Full Text Available System Dynamics was introduced by Jay W. Forrester in the 1960s. Since then the methodology was adopted in many areas of natural or social sciences. This article tries to present briefly how this methodology works, both as Systems Thinking and as Modelling with Vensim computer software.

  8. Safety of sublingual immunotherapy Timothy grass tablet in subjects with allergic rhinitis with or without conjunctivitis and history of asthma

    DEFF Research Database (Denmark)

    Maloney, J; Durham, S; Skoner, D

    2015-01-01

    BACKGROUND: Patients with asthma may be more susceptible to adverse events (AEs) with sublingual immunotherapy tablet (SLIT-tablet) treatment, such as severe systemic reactions and asthma-related events. Using data from eight trials of grass SLIT-tablet in subjects with allergic rhinitis with/wit...

  9. Predicting the Drug Release Kinetics of Matrix Tablets

    CERN Document Server

    Baeumer, Boris; Hinow, Peter; Rades, Thomas; Radunskaya, Ami; Tucker, Ian

    2008-01-01

    In this paper we develop two mathematical models to predict the release kinetics of a water soluble drug from a polymer/excipient matrix tablet. The first of our models consists of a random walk on a weighted graph, where the vertices of the graph represent particles of drug, excipient and polymer, respectively. The graph itself is the contact graph of a multidisperse random sphere packing. The second model describes the dissolution and the subsequent diffusion of the active drug out of a porous matrix using a system of partial differential equations. The predictions of both models show good qualitative agreement with experimental release curves. The models will provide tools for designing better controlled release devices.

  10. Crystallographic control on the substructure of nacre tablets.

    Science.gov (United States)

    Checa, Antonio G; Mutvei, Harry; Osuna-Mascaró, Antonio J; Bonarski, Jan T; Faryna, Marek; Berent, Katarzyna; Pina, Carlos M; Rousseau, Marthe; Macías-Sánchez, Elena

    2013-09-01

    Nacre tablets of mollusks develop two kinds of features when either the calcium carbonate or the organic portions are removed: (1) parallel lineations (vermiculations) formed by elongated carbonate rods, and (2) hourglass patterns, which appear in high relief when etched or in low relief if bleached. In untreated tablets, SEM and AFM data show that vermiculations correspond to aligned and fused aragonite nanogloblules, which are partly surrounded by thin organic pellicles. EBSD mapping of the surfaces of tablets indicates that the vermiculations are invariably parallel to the crystallographic a-axis of aragonite and that the triangles are aligned with the b-axis and correspond to the advance of the {010} faces during the growth of the tablet. According to our interpretation, the vermiculations appear because organic molecules during growth are expelled from the a-axis, where the Ca-CO3 bonds are the shortest. In this way, the subunits forming nacre merge uninterruptedly, forming chains parallel to the a-axis, whereas the organic molecules are expelled to the sides of these chains. Hourglass patterns would be produced by preferential adsorption of organic molecules along the {010}, as compared to the {100} faces. A model is presented for the nanostructure of nacre tablets. SEM and EBSD data also show the existence within the tablets of nanocrystalline units, which are twinned on {110} with the rest of the tablet. Our study shows that the growth dynamics of nacre tablets (and bioaragonite in general) results from the interaction at two different and mutually related levels: tablets and nanogranules.

  11. Modeling Sustainable Food Systems

    Science.gov (United States)

    Allen, Thomas; Prosperi, Paolo

    2016-05-01

    The processes underlying environmental, economic, and social unsustainability derive in part from the food system. Building sustainable food systems has become a predominating endeavor aiming to redirect our food systems and policies towards better-adjusted goals and improved societal welfare. Food systems are complex social-ecological systems involving multiple interactions between human and natural components. Policy needs to encourage public perception of humanity and nature as interdependent and interacting. The systemic nature of these interdependencies and interactions calls for systems approaches and integrated assessment tools. Identifying and modeling the intrinsic properties of the food system that will ensure its essential outcomes are maintained or enhanced over time and across generations, will help organizations and governmental institutions to track progress towards sustainability, and set policies that encourage positive transformations. This paper proposes a conceptual model that articulates crucial vulnerability and resilience factors to global environmental and socio-economic changes, postulating specific food and nutrition security issues as priority outcomes of food systems. By acknowledging the systemic nature of sustainability, this approach allows consideration of causal factor dynamics. In a stepwise approach, a logical application is schematized for three Mediterranean countries, namely Spain, France, and Italy.

  12. Preparation and biological efficacy of haddock bone calcium tablets

    Institute of Scientific and Technical Information of China (English)

    霍健聪; 邓尚贵; 谢超; 童国忠

    2010-01-01

    To investigate the possible use of waste products obtained after processing haddock, the present study prepared haddock bone calcium powder by NaOH and ethanol soaking (alkalinealcohol method) and prepared haddock bone calcium tablets using the powder in combination with appropriate excipients. The biological efficacy of the haddock bone calcium tablets was investigated using Wistar rats as an experiment model. Results show that the optimal parameters for the alkalinealcohol method are: NaOH concentration 1...

  13. Smartphones, tablets and mobile applications for radiology

    Energy Technology Data Exchange (ETDEWEB)

    Székely, András, E-mail: andras.szekely@gmail.com [Kenézy Hospital Department of Radiology, 4043 Debrecen, Bartók Béla út 2-26 (Hungary); Talanow, Roland, E-mail: roland@talanow.info [P.O. Box 1570, Lincoln, CA 95648 (United States); Bágyi, Péter [Kenézy Hospital Department of Radiology, 4043 Debrecen, Bartók Béla út 2-26 (Hungary)

    2013-05-15

    Background: Smartphones are phone devices that may also be used for browsing, navigation and running smaller computer programs called applications. One may consider them as compact personal computers which are primarily to be used for making phone calls. Tablets or “tablet PCs” are fully functioning standalone computers the size of a thin LCD monitor that use the screen itself for control and data input. Both of these devices may be categorized based on the mobile operating system that they use. The aim of this study is to illustrate how smartphones and tablets can be used by diagnostic imaging professionals, radiographers and residents, and to introduce relevant applications that are available for their field. Materials and methods: A search was performed on iTunes, Android Market, Blackberry App World, and Windows Phone Marketplace for mobile applications pertinent to the field of diagnostic imaging. The following terms were applied for the search strategy: (1) radiology, (2) X-ray, (3) ultrasound, (4) MRI, (5) CT, (6) radiographer, (7) nuclear medicine. Two radiologists and one radiology resident reviewed the results. Our review was limited to english-language software. Additional applications were identified by reviewing the list of similar software provided in the description of each application. We downloaded and installed all applications that appeared relevant to an appropriate mobile phone or tablet device. Results: We identified and reviewed a total of 102 applications. We ruled out 1 non-English application and 20 other applications that were created for entertainment purposes. Thus our final list includes 81 applications in the following five categories: diagnostic reading, decision support applications, medical books, interactive encyclopedias, and journal reading programs. Conclusion: Smartphones and tablets offer new opportunities for diagnostic imaging practitioners; these easy-to-use devices equipped with excellent display may be used for

  14. Smartphones, tablets and mobile applications for radiology.

    Science.gov (United States)

    Székely, András; Talanow, Roland; Bágyi, Péter

    2013-05-01

    Smartphones are phone devices that may also be used for browsing, navigation and running smaller computer programs called applications. One may consider them as compact personal computers which are primarily to be used for making phone calls. Tablets or "tablet PCs" are fully functioning standalone computers the size of a thin LCD monitor that use the screen itself for control and data input. Both of these devices may be categorized based on the mobile operating system that they use. The aim of this study is to illustrate how smartphones and tablets can be used by diagnostic imaging professionals, radiographers and residents, and to introduce relevant applications that are available for their field. A search was performed on iTunes, Android Market, Blackberry App World, and Windows Phone Marketplace for mobile applications pertinent to the field of diagnostic imaging. The following terms were applied for the search strategy: (1) radiology, (2) X-ray, (3) ultrasound, (4) MRI, (5) CT, (6) radiographer, (7) nuclear medicine. Two radiologists and one radiology resident reviewed the results. Our review was limited to english-language software. Additional applications were identified by reviewing the list of similar software provided in the description of each application. We downloaded and installed all applications that appeared relevant to an appropriate mobile phone or tablet device. We identified and reviewed a total of 102 applications. We ruled out 1 non-English application and 20 other applications that were created for entertainment purposes. Thus our final list includes 81 applications in the following five categories: diagnostic reading, decision support applications, medical books, interactive encyclopedias, and journal reading programs. Smartphones and tablets offer new opportunities for diagnostic imaging practitioners; these easy-to-use devices equipped with excellent display may be used for diagnostic reading, reference, learning, consultation, and for

  15. POLYSACCHARIDE MATRIX TABLET FOR COLON SPECIFIC DRUG DELIVERY

    OpenAIRE

    Amit Kumar Panigrahi et al

    2012-01-01

    The objective of the present study was to prepare a matrix tablet for colon targeting. Natural gaums (guar gum and xanthan gum) were used for the preparation of colon targeted drug delivery system. Different concentrations of guar gum and xanthan gum and their combinations were tried for the purpose. The prepared tablets were evaluated for in-process parameters as well as colon targeting characteristics. The colon targeting properties were evaluated by analysing the formulations for drug rele...

  16. Monitoring the hydrolyzation of aspirin during the dissolution testing for aspirin delayed-release tablets with a fiber-optic dissolution system

    Institute of Scientific and Technical Information of China (English)

    Yan Wang; Ping-Ping Xu; Xin-Xia Li; Kun Nie; Ming-Fu Tuo; Bin Kong; Jian Chen

    2012-01-01

    The purpose of this study was to investigate the hydrolyzation of aspirin during the process of dissolution testing for aspirin delayed-release tablets. Hydrolysis product of salicylic acid can result in adverse effects and affect the determination of dissolution rate assaying. In this study, the technique of differential spectra was employed, which made it possible to monitor the dissolution testing in situ. The results showed that the hydrolyzation of aspirin made the percentage of salicylic acid exceed the limit of free salicylic acid (4.0), and the hydrolyzation may affect the quality detection of aspirin delayed-release tablets.

  17. Assessing Student Writing on Tablets

    Science.gov (United States)

    Davis, Laurie Laughlin; Orr, Aline; Kong, Xiaojing; Lin, Chow-Hong

    2015-01-01

    There is increasing expectation that schools should be able to use tablets for a range of instructional and assessment purposes. This article considers the comparability of student writing on tablets and laptops to ensure that writing assessment is conducted in a way that is fair to all students. Data were collected from a sample of 826 students…

  18. Tablet PCs: The Write Approach

    Science.gov (United States)

    Milner, Jacob

    2006-01-01

    This article discusses the transforming effects of tablet PCs in the classroom. As 1-to-1 computing becomes the goal on K-12 campuses, school districts are turning to this newer, pen-based technology. Saint Mary's School's new Lenovo ThinkPad X41 tablet PCs had transformed the way Saint Mary's teachers did their jobs. Teachers created outlines for…

  19. Modeling Complex Systems

    CERN Document Server

    Boccara, Nino

    2010-01-01

    Modeling Complex Systems, 2nd Edition, explores the process of modeling complex systems, providing examples from such diverse fields as ecology, epidemiology, sociology, seismology, and economics. It illustrates how models of complex systems are built and provides indispensable mathematical tools for studying their dynamics. This vital introductory text is useful for advanced undergraduate students in various scientific disciplines, and serves as an important reference book for graduate students and young researchers. This enhanced second edition includes: . -recent research results and bibliographic references -extra footnotes which provide biographical information on cited scientists who have made significant contributions to the field -new and improved worked-out examples to aid a student’s comprehension of the content -exercises to challenge the reader and complement the material Nino Boccara is also the author of Essentials of Mathematica: With Applications to Mathematics and Physics (Springer, 2007).

  20. Rapid identification Phenytoin Sodium Tablets by NIR conformity test model%近红外一致性检验模型快速鉴别苯妥英钠片

    Institute of Scientific and Technical Information of China (English)

    李连杰; 李杨; 黄德友; 刘娟; 蒋登高

    2014-01-01

    OBJECTIVE To identify Phenytoin tablets rapidly by near infrared ( NIR).METHODS The ob-ject was phenyion sodium tablets which was procluced by different enterprises ,and optical fiber probe was used to test the near-infrared spectral reflectance .The spectral preprocessing methods were the first derivative and vector normali-zation method .The range of spectrum were 9000~7500 cm-1、6900~5600 cm-1 and 5000~4250 cm -1 .RESULTS Phenytoin sodium tablets model could accurately identify and distinguish between different manufactur -ers.CONCLUSION The established method can provide a reference for the rapid identification of phenytoin sodi -um tablets from different manufacturers.%目的:利用近红外光谱法快速鉴别苯妥英钠片的真伪。方法以全国不同企业生产的苯妥英钠片为分析对象,用光纤探头测定近红外反射光谱,光谱预处理方法为一阶导数和矢量归一化法,谱段范围为9000~7500cm -1、6900~5600cm -1和5000~4250cm -1。结果模型能准确鉴别苯妥英钠片并区分不同的生产厂家。结论所建立的方法可以为快速鉴别不同厂家生产的苯妥英钠片提供参考。

  1. Bioequivalency of ranitidine tablets.

    Science.gov (United States)

    Alkaysi, H N; Salem, M A; Gharaibeh, A M; el-Sayed, Y M; Ali-Gharaibeh, K I; Badwan, A A

    1989-04-01

    The bioavailability of two brands of ranitidine tablets was studied in 10 healthy volunteers. Formulation factors were compared by performing disintegration, dissolution and content uniformity tests. Plasma concentrations of ranitidine were measured using a sensitive and precise high pressure liquid chromatographic (HPLC) procedure. Pharmacokinetic parameters were determined for both formulations and included: Cmax, AUCt, AUC infinity, tmax, t1/2 and the terminal rate of elimination (k). Statistical analysis revealed that differences between the brands were not significant. The two formulations can be considered to be bioequivalent.

  2. Tablets i skolen

    DEFF Research Database (Denmark)

    Lorentzen, Rasmus Fink

    2012-01-01

    Denne rapport afslutter CELMS undersøgelse af Odder Kommunes projekt med indførelse af iPads på alle kommunens skoler. Undersøgelsen har til formål at belyse om der er pædagogiske og læringsmæssige fordele forbundet med brugen af tablets i undervisningen i grundskolen og i givet fald hvilke...... designer og tablet’ens egenskaber i et generelt perspektiv. Rapporten afsluttes med en række anbefalinger til henholdsvis lærere og skoleledere med henblik på videre udvikling af indsatsen....

  3. Distributed generation systems model

    Energy Technology Data Exchange (ETDEWEB)

    Barklund, C.R.

    1994-12-31

    A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.

  4. Modeling the earth system

    Energy Technology Data Exchange (ETDEWEB)

    Ojima, D. [ed.

    1992-12-31

    The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.

  5. Windows for tablets for dummies

    CERN Document Server

    Rathbone, Andy

    2013-01-01

    Just for you--Windows 8 from the tablet user's perspective If you're an experienced Windows user, you don't need a guide to everything that Windows 8 can do, just to those tools and functions that work on your tablet. And so here it is. This new book zeros in on what you need to know to work best on your tablet with Windows 8. Topics include navigating the new Windows 8 interface and how it works on a touchscreen, how to safely connect to the Internet, how to work with apps or share your tablet in a group, and much more. If you're a new tablet user, you'll particularly appre

  6. Evaluation of chitosan–anionic polymers based tablets for extended-release of highly water-soluble drugs

    Directory of Open Access Journals (Sweden)

    Yang Shao

    2015-02-01

    Full Text Available The objective of this study is to develop chitosan–anionic polymers based extended-release tablets and test the feasibility of using this system for the sustained release of highly water-soluble drugs with high drug loading. Here, the combination of sodium valproate (VPS and valproic acid (VPA were chosen as the model drugs. Anionic polymers studied include xanthan gum (XG, carrageenan (CG, sodium carboxymethyl cellulose (CMC-Na and sodium alginate (SA. The tablets were prepared by wet granulation method. In vitro drug release was carried out under simulated gastrointestinal condition. Drug release mechanism was studied. Compared with single polymers, chitosan–anionic polymers based system caused a further slowdown of drug release rate. Among them, CS–xanthan gum matrix system exhibited the best extended-release behavior and could extend drug release for up to 24 h. Differential scanning calorimetry (DSC and Fourier transform infrared spectroscopy (FTIR studies demonstrated that polyelectrolyte complexes (PECs were formed on the tablet surface, which played an important role on retarding erosion and swelling of the matrix in the later stage. In conclusion, this study demonstrated that it is possible to develop highly water-soluble drugs loaded extended-release tablets using chitosan–anionic polymers based system.

  7. FORMULATION DEVELOPMENT OF ISOXSUPRINE HYDROCHLORIDE MODIFIED RELEASE MATRIX TABLETS

    Directory of Open Access Journals (Sweden)

    Ketan Patel

    2012-01-01

    Full Text Available The objective of the present investigation was to study the effect of critical formulation parameters affecting release of isoxsuprine hydrochloride from matrix tablets using combination of polyethylene oxide (PEO and dicalcium phosphate (DCP. The powder blend consisting of drug and excipients was analyzed for angle of repose, Carr’s index and Hausner’s ratio. The tablets were prepared by direct compression method. To assess the compressional behavior of the drug-excipient blend, the tablets were analyzed for friability and crushing strength. The in vitro drug release study was carried out in distilled water. The powder blend exhibited satisfactorily flow as measured by angle of repose, Carr’s index and Hausner’s ratio. The formulation ingredients showed satisfactory tableting properties (friability <1%, crushing strength ≥ 4 kgf. The drug release was modified on addition of PEO and DCP. Addition of 5 to 25% DCP in the formulation of matrix tablets caused apparent difference in the drug dissolution in distilled water. However, the difference was insignificant as analyzed by analysis of variance (ANOVA and similarity factor ( f2. The drug release from the tablets was best explained by Weibull model. Unified Weibull model was evolved to predict drug release from the formulated batches. The findings of this investigation can be extended to industry to cut down the cost of formulation and to by-pass the existing patents employing hydrophilic matrixing agents, at least for selective drugs.

  8. Grewia polysaccharide as a pharmaceutical excipient in matrix tablets

    Directory of Open Access Journals (Sweden)

    Elijah I. Nep

    2011-03-01

    Full Text Available Matrix-based tablets using different concentrations of grewia gum, and the model drug ibuprofen, were prepared using a wet granulation technique. Similar formulations were also prepared using HPMC, guar gum or ethyl cellulose as the polymer matrix. In addition to tablet properties, swelling and erosion of tablets and kinetics of drug release were also investigated. In vitro drug release studies, in phosphate buffer (pH 7.2 using USP type II apparatus, revealed that grewia gum at concentrations of 16%, 32% and 48% can sustain therelease of ibuprofen tablets for up to 24 hours. Release profiles were similar to those tablets containing ethyl cellulose as the matrix former. Swelling and erosion of grewia gum matrices occurred simultaneously, and ibuprofen release was by anomalous diffusion in accordance with the Korsmeyer-Peppas model. There was evidence suggesting synergism between grewia gum and guar gum in sustaining the release of ibuprofen from tablets when used in the ratio 2:1. Grewia gum may therefore prove a useful excipient, when used on its own, or in combination with other polymers, to modify drug release.

  9. Ionotropic Cross-linked Carbo-protein Micro Matrix System: An Approach for Improvement of Drug Release, Compaction and Tableting behavior of Losartan Potassium.

    Science.gov (United States)

    Khandai, Madhusmruti; Chakraborty, Santanu; Ghosh, Ashoke Kumar

    2015-01-01

    The aim of the present research work is to develop carbo-protein polymeric complex based sustain release microspheres of losartan potassium and investigate the ability of this dosage form to improve the flowability, compressibility and tableting properties of losartan potassium. The influence of silk sericin, alginate and its blend on various physicochemical parameters and in vitro drug release pattern were studied to optimize the concentration of polymeric blend required for 12 h. sustain release. Optimized batch was subjected to different flowability, compressibility and tableting properties studies to observe the effects of carbo-protein microspheres on flow properties. Results indicated that the concentration of sericin was found to be the main influential factor for prolonged drug release. Different micromeritic studies revealed that the poor flowability and compressibility properties of pure losartan potassium were significantly improved by this algino-sericin microspheric dosage form. Research findings also revealed that plasticity, die filling behavior and tableting properties of the pure drug were significantly improved by this microsphere formulation. So these prospective results concluded that carbo-protein polymeric microspheres helps to sustain the drug release for prolong hours as well as improve the flowability, compressibility and tableting properties of losartan potassium.

  10. FORMULATION AND EVALUATION OF GASTRO RETENTIVE FLOATING TABLETS OF GLICLAZIDE

    Directory of Open Access Journals (Sweden)

    Thakkar Hardik Kumar Rajeshbhai

    2011-04-01

    Full Text Available A gastro retentive floating drug delivery system containing gliclazide was prepared in the form of tablet and evaluated for its processing parameters and in vitro release behaviour. Gliclazide is a selective second-generation sulphonyl urea used in treatment of hyperglycemia and it absorbs rapidly and completely. However its absorption is erratic in diabetic patient due to its impaired gastric motility or gastric emptying. To overcome these drawbacks, the present investigation was to develop a gastro retentive floating tablets of gliclazide. Ten formulations containing retardant materials such as hydroxypropylmethylcellulose K4M and K15M, sodium bicarbonate was used as a gas generating agent to reduce floating lag time and other release promoters. Tablets remained buoyant over 12 hours in the release medium, and the amount of sodium bicarbonate found to be significant for not only to remaining buoyant without causing disintegration of the tablet, but also to release of the drug in the acidic medium. Final F6 optimized formulation released approximately 99% drug in 12 hours in vitro, while the floating lag time was 39 sec and tablet remained floatable throughout all studies. In vitro gastro retentive study of tablets gave successful results by floating in gastric content over a period of 24 hours. The results of the current study clearly indicate, a promising potential of the gliclazide floating system as an alternative to the conventional dosage form.

  11. Tablet Personal Computer Integration in Higher Education: Applying the Unified Theory of Acceptance and Use Technology Model to Understand Supporting Factors

    Science.gov (United States)

    Moran, Mark; Hawkes, Mark; El Gayar, Omar

    2010-01-01

    Many educational institutions have implemented ubiquitous or required laptop, notebook, or tablet personal computing programs for their students. Yet, limited evidence exists to validate integration and acceptance of the technology among student populations. This research examines student acceptance of mobile computing devices using a modification…

  12. Mechanical Systems, Classical Models

    CERN Document Server

    Teodorescu, Petre P

    2009-01-01

    This third volume completes the Work Mechanical Systems, Classical Models. The first two volumes dealt with particle dynamics and with discrete and continuous mechanical systems. The present volume studies analytical mechanics. Topics like Lagrangian and Hamiltonian mechanics, the Hamilton-Jacobi method, and a study of systems with separate variables are thoroughly discussed. Also included are variational principles and canonical transformations, integral invariants and exterior differential calculus, and particular attention is given to non-holonomic mechanical systems. The author explains in detail all important aspects of the science of mechanics, regarded as a natural science, and shows how they are useful in understanding important natural phenomena and solving problems of interest in applied and engineering sciences. Professor Teodorescu has spent more than fifty years as a Professor of Mechanics at the University of Bucharest and this book relies on the extensive literature on the subject as well as th...

  13. MOUTH DISSOLVING TABLET: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Kulkarni S. D.

    2011-04-01

    Full Text Available Mouth dissolving Tablets disintegrate and/or dissolve rapidly in the saliva without the need for water. Some tablets are designed to dissolve in saliva extremely fast, within a few seconds, and are true fast-dissolving tablets. Others contain agents to enhance the rate of tablet disintegration in the oral cavity, and are more appropriately termed fast-disintegrating tablets, as they may take up to a minute to completely disintegrate. Mouth or Fast dissolving tablets have been formulated for pediatric, geriatric and bedridden patients and in the many elderly persons will have difficulties in taking conventional oral dosage forms because of hand tremors and dysphagia. The technologies used for manufacturing fast-dissolving tablets are freeze-drying, spray-drying, molding, sublimation, sugar-based excipients, compression, and disintegration addition. As a result of increased life expectancy, the elderly constitute a large portion of the worldwide population today. These people eventually will experience deterioration of their physiological and physical abilities.

  14. Aqueous coating dispersion (pseudolatex) of zein improves formulation of sustained-release tablets containing very water-soluble drug.

    Science.gov (United States)

    Li, X N; Guo, H X; Heinamaki, J

    2010-05-01

    Zein is an alcohol soluble protein of corn origin that exhibits hydrophobic properties. Pseudolatexes are colloidal dispersions containing spherical solid or semisolid particles less than 1 microm in diameter and can be prepared from any existing thermoplastic water-insoluble polymer. The novel plasticized film-coating pseudolatex of zein was studied in formulation of sustained-release tablets containing very water-soluble drug. Film formation of plasticized aqueous dispersion was compared with film forming properties of plasticized organic solvent system (ethanol) of zein. The water vapor permeability (WVP), water uptake and erosion, and moisture sorption were evaluated with free films. The tablets containing metoprolol tartrate as a model drug were used in pan-coating experiments. Aqueous film coatings plasticized with PEG 400 exhibited very low water uptake. No significant difference in WVP, moisture sorption and erosion were found between aqueous films and organic solvent-based films of zein plasticized with PEG 400. The atomic force microscopy (AFM) images on microstructure of films showed that colloidal particle size of zein in the aqueous films was smaller than that observed in the solvent-based films. In addition, the aqueous-based films were more compact and smoother than the respective solvent-based films. The aqueous zein-coated tablets containing very water-soluble drug (metoprolol tartrate) exhibited clear sustained-release dissolution profiles in vitro, while the respective solvent-based film-coated tablets showed much faster drug release. Furthermore, aqueous zein-coated tablets had lower water absorption at high humidity conditions. In conclusion, the plasticized aqueous dispersion (pseudolatex) of zein can be used for moisture resistant film coating of sustained-release tablets containing very water-soluble drug.

  15. Dutch distribution zones of stable iodine tablets based on atmospheric dispersion modelling of accidental releases from nuclear power plants.

    NARCIS (Netherlands)

    Kok-Palma, Y.S.; Leenders, M.; Meulenbelt, J.

    2010-01-01

    Rapid administration of stable iodine is essential for the saturation and subsequent protection of the thyroid gland against the potential harm caused by radioiodines. This paper proposes the Dutch risk analysis that uses an atmospheric dispersion model to calculate the size of the zones around nucl

  16. EFFECT OF TABLET FORMULATION VARIABLES ON TRAMADOL HCL ELEMENTARY OSMOTIC PUMP TABLET

    OpenAIRE

    Basani Gavaskar; Dilip Dodda; Subash Vijaya Kumar

    2010-01-01

    Osmotic drug delivery system utilize osmotic pressure as a energy source and driving force for delivery of drugs, pH presence of food under physiological factors may affect drug release from conventional controlled release system (Matrices and reservoirs), where as drug release from osmotic system is independent of these factors to a large extent. The aim of the current study was to formulate elementary osmotic pump tablets of water soluble Tramadol HCl. Formulation were prepared based on wet...

  17. NEP systems model

    Science.gov (United States)

    George, Jeffrey A.

    A new nuclear electric propulsion (NEP) systems analysis code is discussed. The new code is modular and consists of a driver code and various subsystem models. The code models five different subsystems: (1) reactor/shield; (2) power conversion; (3) heat rejection; (4) power management and distribution (PMAD); and (5) thrusters. The code optimizes for the following design criteria: minimum mass; minimum radiator area; and low mass/low area. The code also optimizes the following parameters: separation distance; temperature ratio; pressure ratio; and transmission frequency. The discussion is presented in vugraph form.

  18. Optimization of matrix tablets controlled drug release using Elman dynamic neural networks and decision trees.

    Science.gov (United States)

    Petrović, Jelena; Ibrić, Svetlana; Betz, Gabriele; Đurić, Zorica

    2012-05-30

    The main objective of the study was to develop artificial intelligence methods for optimization of drug release from matrix tablets regardless of the matrix type. Static and dynamic artificial neural networks of the same topology were developed to model dissolution profiles of different matrix tablets types (hydrophilic/lipid) using formulation composition, compression force used for tableting and tablets porosity and tensile strength as input data. Potential application of decision trees in discovering knowledge from experimental data was also investigated. Polyethylene oxide polymer and glyceryl palmitostearate were used as matrix forming materials for hydrophilic and lipid matrix tablets, respectively whereas selected model drugs were diclofenac sodium and caffeine. Matrix tablets were prepared by direct compression method and tested for in vitro dissolution profiles. Optimization of static and dynamic neural networks used for modeling of drug release was performed using Monte Carlo simulations or genetic algorithms optimizer. Decision trees were constructed following discretization of data. Calculated difference (f(1)) and similarity (f(2)) factors for predicted and experimentally obtained dissolution profiles of test matrix tablets formulations indicate that Elman dynamic neural networks as well as decision trees are capable of accurate predictions of both hydrophilic and lipid matrix tablets dissolution profiles. Elman neural networks were compared to most frequently used static network, Multi-layered perceptron, and superiority of Elman networks have been demonstrated. Developed methods allow simple, yet very precise way of drug release predictions for both hydrophilic and lipid matrix tablets having controlled drug release.

  19. [Pharmaceutical technology of Cordaflex tablets].

    Science.gov (United States)

    Erdös, S

    1996-01-01

    First the possibilities of solubilization and the photosensibility of nifedipine (the active ingredient of Cordaflex tablets) were investigated. The technology of retard tablet involves the preparation of a coprecipitate through spraying a solution containing nifedipine, a hydrotropic and a reardizing substance on carrier. After drying the produced granulated material was blended with common auxiliary ingredients, compressed into tablet and coated. The ratio of the two types of coprecipitating substances has a direct effect on the dissolution, so it proved predictable. The reproducibility of technology was good.

  20. Preparation and biological efficacy of haddock bone calcium tablets

    Science.gov (United States)

    Huo, Jiancong; Deng, Shanggui; Xie, Chao; Tong, Guozhong

    2010-03-01

    To investigate the possible use of waste products obtained after processing haddock, the present study prepared haddock bone calcium powder by NaOH and ethanol soaking (alkalinealcohol method) and prepared haddock bone calcium tablets using the powder in combination with appropriate excipients. The biological efficacy of the haddock bone calcium tablets was investigated using Wistar rats as an experiment model. Results show that the optimal parameters for the alkalinealcohol method are: NaOH concentration 1 mol/L, immersion time 30 h; ethanol concentration 60%, immersion time 15 h. A mixture of 2% polyvinylpyrrolidone in ethanol was used as an excipient at a ratio of 1:2 to full-cream milk powder, without the use of a disintegrating agent. This process provided satisfactory tablets in terms of rigidity and taste. Animal studies showed that the haddock bone calcium tablets at a dose of 2 g·kg-1·d-1 or 5g·kg-1·d-1 significantly increased blood calcium and phosphorus levels and bone calcium content in rats. Therefore, these tablets could be used for calcium supplementation and prevent osteoporosis. Although the reasons of high absorption in the rats fed with haddock bone calcium tablets are unclear, it is suggested that there are some factors, such as treatment with method of alkaline-alcohol or the added milk, may play positive roles in increasing absorption ratio.

  1. Formulation Development and Optimization of Matrix Tablet of Tramadol Hydrochloride.

    Science.gov (United States)

    Deb, Pulak; Singha, Jubaraj; Chanda, Indranil; Chakraborty, Prithviraj

    2017-01-01

    The aim of the present investigation is to formulate and optimize oral sustained release matrix tablet of highly water soluble drug Tramadol HCl and to evaluate the effect of varying concentration of hydrophilic and hydrophobic polymer on drug release, based on a survey done on the recent patents of Tramadol HCl (US7374781, CA 2479252) and sustained release matrix tablets. The tablets were prepared by double granulation process, by melt granulation and wet granulation technique using Carnauba wax (CW) and HPMC K100 as release retardant. Pre and post compression factors were evaluated and all the parameters were found within the limit. The drug release data were subjected to different models in order to evaluate release kinetics and mechanism of drug release. The prepared formulations showed drug release in the range 100±2% in 6hrs, 7hrs, 8hrs and 9hrs and upto 12 hrs respectively. The optimized tablet having 25% CW and 20% HPMC showed sustained drug release pattern. Hydrophilic matrix of HPMC alone could not control the Tramadol release effectively for 12 h whereas when combined with CW could slow down the release of drug and can be successfully employed for formulating sustained-release matrix tablets. Similarity factor, f2 shows the test and reference profile are identical. Double granulation technique with CW and HPMC K100 proved as a better technique for sustaining the drug release from the matrix tablet. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Desktop 3D printing of controlled release pharmaceutical bilayer tablets.

    Science.gov (United States)

    Khaled, Shaban A; Burley, Jonathan C; Alexander, Morgan R; Roberts, Clive J

    2014-01-30

    Three dimensional (3D) printing was used as a novel medicine formulation technique for production of viable tablets capable of satisfying regulatory tests and matching the release of standard commercial tablets. Hydroxypropyl methylcellulose (HPMC 2208) (Methocel™ K100M Premium) and poly(acrylic acid) (PAA) (Carbopol(®) 974P NF) were used as a hydrophilic matrix for a sustained release (SR) layer. Hypromellose(®) (HPMC 2910) was used as a binder while microcrystalline cellulose (MCC) (Pharmacel(®) 102) and sodium starch glycolate (SSG) (Primojel(®)) were used as disintegrants for an immediate release (IR) layer. Commercial guaifenesin bi-layer tablets (GBT) were used as a model drug (Mucinex(®)) for this study. There was a favourable comparison of release of the active guaifenesin from the printed hydrophilic matrix compared with the commercially available GBT. The printed formulations were also evaluated for physical and mechanical properties such as weight variation, friability, hardness and thickness as a comparison to the commercial tablet and were within acceptable range as defined by the international standards stated in the United States Pharmacopoeia (USP). All formulations (standard tablets and 3D printed tablets) showed Korsmeyer-Peppas n values between 0.27 and 0.44 which indicates Fickian diffusion drug release through a hydrated HPMC gel layer. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Crystal coating via spray drying to improve powder tabletability.

    Science.gov (United States)

    Vanhoorne, V; Peeters, E; Van Snick, B; Remon, J P; Vervaet, C

    2014-11-01

    A continuous crystal coating method was developed to improve both flowability and tabletability of powders. The method includes the introduction of solid, dry particles into an atomized spray during spray drying in order to coat and agglomerate individual particles. Paracetamol was used as a model drug as it exhibits poor flowability and high capping tendency upon compaction. The particle size enlargement and flowability were evaluated by the mean median particle size and flow index of the resulting powders. The crystal coating coprocessing method was successful for the production of powders containing 75% paracetamol with excellent tableting properties. However, the extent of agglomeration achieved during coprocessing was limited. Tablets compressed on a rotary tablet press in manual mode showed excellent compression properties without capping tendency. A formulation with 75% paracetamol, 5% PVP and 20% amorphous lactose yielded a tensile strength of 1.9 MPa at a compression pressure of 288 MPa. The friability of tablets compressed at 188 MPa was only 0.6%. The excellent tabletability of this formulation was attributed to the coating of paracetamol crystals with amorphous lactose and PVP through coprocessing and the presence of brittle and plastic components in the formulation. The coprocessing method was also successfully applied for the production of directly compressible lactose showing improved tensile strength and friability in comparison to a spray dried direct compression lactose grade.

  4. National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.W. (Energy Information Administration, Washington, DC (United States))

    1993-01-01

    The Energy Information Administration is developing a new National Energy Modeling System to provide annual forecasts of energy supply, demand, and prices on a regional basis in the United States and, to a limited extent, in the rest of the world. The design for the system was based on a requirements analysis, a comparison of requirements with existing modeling capabilities, and a series of widely circulated issue papers defining the choices and tradeoffs for 13 key design decisions. An initial prototpye of the new NEMS was implemented in late 1992, with a more complete, operational version in 1993. NEMS is expected to provide EIA and other users with a greatly enhanced ability to illustrate quickly and effectively the effects of a wide range of energy policy proposals.

  5. Formulation and Characterization of Cetylpyridinium Chloride Bioadhesive Tablets

    Directory of Open Access Journals (Sweden)

    Jafar Akbari

    2014-12-01

    Full Text Available Purpose: Bioadhesive polymers play an important role in biomedical and drug delivery applications. The aim of this study is to develop a sustained- release tablet for local application of Cetylpyridinium Chloride (CPC. This delivery system would supply the drug at an effective level for a long period of time, and thereby overcome the problem of the short retention time of CPC and could be used for buccal delivery as a topical anti-infective agent. Methods: CPC bioadhesive tablets were directly prepared using 7 mm flat-faced punches on a hydraulic press. The materials for each tablet were weighted, introduced into the die and compacted at constant compression pressure. The dissolution tests were performed to the rotation paddle method and the bioadhesive strength of the tablets were measured. Results: The results showed that as the concentration of polymer increased, the drug release rate was decreased. Also the type and ratio of polymers altered the release kinetic of Cetylpyridinium Chloride from investigated tablets. The bioadhesion strength increased with increasing the concentration of polymer and maximum bioadhesion strength was observed with HPMC K100M. Conclusion: The selected formulation of CPC bioadhesive tablet can be used as a suitable preparation for continuous release of CPC with appropriate bioadhesion strength.

  6. Research data collection methods: from paper to tablet computers.

    Science.gov (United States)

    Wilcox, Adam B; Gallagher, Kathleen D; Boden-Albala, Bernadette; Bakken, Suzanne R

    2012-07-01

    Primary data collection is a critical activity in clinical research. Even with significant advances in technical capabilities, clear benefits of use, and even user preferences for using electronic systems for collecting primary data, paper-based data collection is still common in clinical research settings. However, with recent developments in both clinical research and tablet computer technology, the comparative advantages and disadvantages of data collection methods should be determined. To describe case studies using multiple methods of data collection, including next-generation tablets, and consider their various advantages and disadvantages. We reviewed 5 modern case studies using primary data collection, using methods ranging from paper to next-generation tablet computers. We performed semistructured telephone interviews with each project, which considered factors relevant to data collection. We address specific issues with workflow, implementation and security for these different methods, and identify differences in implementation that led to different technology considerations for each case study. There remain multiple methods for primary data collection, each with its own strengths and weaknesses. Two recent methods are electronic health record templates and next-generation tablet computers. Electronic health record templates can link data directly to medical records, but are notably difficult to use. Current tablet computers are substantially different from previous technologies with regard to user familiarity and software cost. The use of cloud-based storage for tablet computers, however, creates a specific challenge for clinical research that must be considered but can be overcome.

  7. Formulation and Characterization of Cetylpyridinium Chloride Bioadhesive Tablets

    Science.gov (United States)

    Akbari, Jafar; Saeedi, Majid; Morteza-Semnani, Katayoun; Kelidari, Hamidreza; Lashkari, Maryam

    2014-01-01

    Purpose: Bioadhesive polymers play an important role in biomedical and drug delivery applications. The aim of this study is to develop a sustained- release tablet for local application of Cetylpyridinium Chloride (CPC). This delivery system would supply the drug at an effective level for a long period of time, and thereby overcome the problem of the short retention time of CPC and could be used for buccal delivery as a topical anti-infective agent. Methods: CPC bioadhesive tablets were directly prepared using 7 mm flat-faced punches on a hydraulic press. The materials for each tablet were weighted, introduced into the die and compacted at constant compression pressure. The dissolution tests were performed to the rotation paddle method and the bioadhesive strength of the tablets were measured. Results: The results showed that as the concentration of polymer increased, the drug release rate was decreased. Also the type and ratio of polymers altered the release kinetic of Cetylpyridinium Chloride from investigated tablets. The bioadhesion strength increased with increasing the concentration of polymer and maximum bioadhesion strength was observed with HPMC K100M. Conclusion: The selected formulation of CPC bioadhesive tablet can be used as a suitable preparation for continuous release of CPC with appropriate bioadhesion strength. PMID:25436196

  8. Design space construction of multiple dose-strength tablets utilizing bayesian estimation based on one set of design-of-experiments.

    Science.gov (United States)

    Maeda, Jin; Suzuki, Tatsuya; Takayama, Kozo

    2012-01-01

    Design spaces for multiple dose strengths of tablets were constructed using a Bayesian estimation method with one set of design of experiments (DoE) of only the highest dose-strength tablet. The lubricant blending process for theophylline tablets with dose strengths of 100, 50, and 25 mg is used as a model manufacturing process in order to construct design spaces. The DoE was conducted using various Froude numbers (X(1)) and blending times (X(2)) for theophylline 100-mg tablet. The response surfaces, design space, and their reliability of the compression rate of the powder mixture (Y(1)), tablet hardness (Y(2)), and dissolution rate (Y(3)) of the 100-mg tablet were calculated using multivariate spline interpolation, a bootstrap resampling technique, and self-organizing map clustering. Three experiments under an optimal condition and two experiments under other conditions were performed using 50- and 25-mg tablets, respectively. The response surfaces of the highest-strength tablet were corrected to those of the lower-strength tablets by Bayesian estimation using the manufacturing data of the lower-strength tablets. Experiments under three additional sets of conditions of lower-strength tablets showed that the corrected design space made it possible to predict the quality of lower-strength tablets more precisely than the design space of the highest-strength tablet. This approach is useful for constructing design spaces of tablets with multiple strengths.

  9. Modeling Novo Nordisk Production Systems

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth

    1997-01-01

    This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'.......This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'....

  10. In vivo gastric residence and gastroprotective effect of floating gastroretentive tablet of DA-9601, an extract of Artemisia asiatica, in beagle dogs

    Directory of Open Access Journals (Sweden)

    Kim JS

    2016-06-01

    time and a remarkable mucosal restoration effect in animal models. Therefore, the GR system of DA-9601 could be a substitute dosage form for the treatment of gastritis, while reducing the dosing frequency and thus improving patient compliance. Keywords: DA-9601, gastroretentive tablet, controlled release, radiographic studies, gastroprotective effects

  11. Effect of Wendan Tablets on Behaviors and Monoamine Neurotransmitters in Rat Model of Anxiety%温胆片对焦虑模型大鼠行为学和单胺类神经递质的影响

    Institute of Scientific and Technical Information of China (English)

    刘小河; 杨忠奇; 冼绍祥; 杨明晔; 沈淑静; 黄灿; 袁天慧; 王琼

    2012-01-01

    Objective To observe the anti-anxiety effect of Wendan Tablets and its influences on the contents of monoamine neurotransmitters of 5-hydroxytryptamine (5-HT) , norepinephrine (NE) and dopamine (DA) in the hippocampus of rats with anxiety. Methods SD male rats were randomized into blank group, model group, western medicine group and low-, middle-, and high-dose Wendan Tablets groups. Except for the blank group, the rats of the rest groups were stimulated irregularly by empty bottles to induce anxiety. One week later, the rats in the blank group were given oral use of distilled water, western medicine group were given oral use of 10mg/kg diazepam suspension, and low-, middle-, and high-dose Wendan Tablets groups were given oral use of 0. 6, 1.2 and 2. 4 g/kg suspension of Wendan Tablets respectively for 2 weeks. One week after treatment, the times of abnormal behaviors of the rats were observed, and neurotransmitter contents in rat hippocampus were detected by high performance liquid chromatography after treatment for 2 weeks. Results The times of attacking behavior and exploratory behavior of the rats in Wendan Tablets groups were significantly decreased, while the times of grooming behavior were significantly increased. 5-HT, NE and DA contents in the hippocampus of rats were also decreased in Wendan Tablets groups. Conclusion The anti-anxiety mechanism of Wendan Tablets may be associated with decreasing the release of cerebral monoamine neurotransmitters in rats.%[目的]观察温胆片的抗焦虑作用及对大鼠海马组织单胺类神经递质5-羟色胺(5-HT)、去甲肾上腺素(NE)及多巴胺(DA)含量的影响.[方法]选用SD雄性大鼠60只,随机分为6组,即空白对照组,模型组,西药组,温胆片低、中、高剂量组.除空白对照组外,其他组均采取不确定性空瓶应激的方法复制大鼠焦虑模型.空白对照组和模型组以双蒸水灌胃,西药组灌服10 mg/kg地西泮混悬液,温胆片低、

  12. Novel gastroretentive sustained-release tablet of tacrolimus based on self-microemulsifying mixture:in vitro evaluation and in vivo bioavailability test

    Institute of Scientific and Technical Information of China (English)

    Yan-ping WANG; Yong GAN; Xin-xin ZHANG

    2011-01-01

    Aim:To develop a novel gastroretentive drug delivery system based on a self-microemulsifying (SME) lipid mixture for improving the oral absorption of the immunosuppressant tacrolimus.Methods:Liquid SME mixture,composed of Cremophor RH40 and monocaprylin glycerate,was blended with polyethylene oxide,chitosan,polyvinylpyrrolidone and mannitol,and then transformed into tablets via granulation,with ethanol as the wetting agent.The tablets were characterized in respect of swelling,bioadhesive and SME properties.In vitro dissolution was conducted using an HCl buffer at pH 1.2.Oral bioavailability of the tablets was examined in fasted beagle dogs.Results:The tablet could expand to 13.5 mm in diameter and 15 mm in thickness during the initial 20 min of contact with the HClbuffer at pH 1.2.The bioadhesive strength was as high as 0.98±0.06 N/cm2.The SME gastroretentive sustained-release tablets preserved the SME capability of the liquid SME formations under transmission electron microscope.The drug-release curve was fit to the zero-order release model,which was helpful in reducing fluctuations in blood concentration.Compared with the commercially available capsules of tacrolimus,the relative bioavailability of the SME gastroretentive sustained-release tablets was 553.4%±353.8%.Conclusion:SME gastroretentive sustained-release tablets can enhance the oral bioavailability of tacrolimus with poor solubility and a narrow absorption window.

  13. Preparation and evaluation of swelling induced-orally disintegrating tablets by microwave irradiation.

    Science.gov (United States)

    Sano, Syusuke; Iwao, Yasunori; Kimura, Susumu; Itai, Shigeru

    2011-09-15

    A major challenge in the development of orally disintegrating tablets (ODTs) is to achieve a good balance between tablet hardness and disintegration time. In this study, an advanced method was demonstrated to improve these opposing properties in a molded tablet using a one-step procedure that exploits the swelling induced by microwave treatment. Wet molded tablets consisting of the delta form of mannitol and silicon dioxide were prepared and microwave-heated to generate water vapor inside the tablets. This induced either swelling or shrinking of tablets, in the extent of each being dependent on tablet formulation and manufacturing conditions. A two-level full factorial design method was used to evaluate the effects of several variables in formulation and manufacturing conditions on the tablet properties, hardness, disintegration time and change in shape. The variables investigated in this study were: ratio of silicon dioxide in formulation, water volume added in granulation, ratio of water absorbed by silicon dioxide prior to granulation, and microwave irradiation time. Swelling of tablet by microwave irradiation was observed in the batches with high ratio of silicon dioxide and low levels of water volume. The disintegration time was clearly shortened by induction of the swelling, while tablet hardness increased. We demonstrated that the water vapor generated by microwave irradiation promoted a change in the crystalline form of mannitol from delta to beta, and that this may have contributed to an increase in tablet hardness. Additionally, it was found that new solid bridges were formed between the granules in the tablet via the pathway from dissolution of mannitol in water vapor to congelation, resulting in an increase in tablet hardness. Thus, both tablet hardness and disintegration properties of the molded tablets were improved by the proposed one-step method and the appropriate ranges for variables are indicated. In addition, multiple regression modeling was

  14. Solid dispersion matrix tablet comprising indomethacin-PEG-HPMC fabricated with fusion and mold technique

    Directory of Open Access Journals (Sweden)

    Mesnukul A

    2009-01-01

    Full Text Available The purpose of this study is to fabricate the polyethylene glycol matrix tablet by mold technique. Indomethacin and hydroxypropylmethylcellulose were used as model drug and polymer, respectively, in PEG matrix system. The physical and drug release characteristics of developed matrix tablet were studied. This inert carrier system comprising 7:3 polyethylene glycol 4000: polyethylene glycol 400 could effectively enhance the solubility of indomethacin and an addition of hydroxypropylmethylcellulose could sustain the drug release. Scanning electron microscope photomicrograph indicated the drug diffusion outward through the porous network of this developed matrix tablet into the dissolution fluid. Least square fitting the experimental dissolution data to the mathematical expressions (power law, first-order, Higuchi′s and zero-order indicated the drug release kinetics primarily as Fickian diffusion. Both the enhancement of drug dissolution and the prolongation of the drug release could be achieved for aqueous insoluble drug such as, indomethacin, by using polyethylene glycol-hydroxypropylmethylcellulose matrix system prepared with melting and mold technique.

  15. Data-driven analysis of interactions between people with dementia and a tablet device

    Directory of Open Access Journals (Sweden)

    Doneit Wolfgang

    2017-09-01

    Full Text Available In the project I-CARE a technical system for tablet devices is developed that captures the personal needs and skills of people with dementia. The system provides activation content such as music videos, biographical photographs and quizzes on various topics of interest to people with dementia, their families and professional caregivers. To adapt the system, the activation content is adjusted to the daily condition of individual users. For this purpose, emotions are automatically detected through facial expressions, motion, and voice. The daily interactions of the users with the tablet devices are documented in log files which can be merged into an event list. In this paper, we propose an advanced format for event lists and a data analysis strategy. A transformation scheme is developed in order to obtain datasets with features and time series for popular methods of data mining. The proposed methods are applied to analysing the interactions of people with dementia with the I-CARE tablet device. We show how the new format of event lists and the innovative transformation scheme can be used to compress the stored data, to identify groups of users, and to model changes of user behaviour. As the I-CARE user studies are still ongoing, simulated benchmark log files are applied to illustrate the data mining strategy. We discuss possible solutions to challenges that appear in the context of I-CARE and that are relevant to a broad range of applications.

  16. System of systems modeling and analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, James E.; Anderson, Dennis James; Longsine, Dennis E. (Intera, Inc., Austin, TX); Shirah, Donald N.

    2005-01-01

    This report documents the results of an LDRD program entitled 'System of Systems Modeling and Analysis' that was conducted during FY 2003 and FY 2004. Systems that themselves consist of multiple systems (referred to here as System of Systems or SoS) introduce a level of complexity to systems performance analysis and optimization that is not readily addressable by existing capabilities. The objective of the 'System of Systems Modeling and Analysis' project was to develop an integrated modeling and simulation environment that addresses the complex SoS modeling and analysis needs. The approach to meeting this objective involved two key efforts. First, a static analysis approach, called state modeling, has been developed that is useful for analyzing the average performance of systems over defined use conditions. The state modeling capability supports analysis and optimization of multiple systems and multiple performance measures or measures of effectiveness. The second effort involves time simulation which represents every system in the simulation using an encapsulated state model (State Model Object or SMO). The time simulation can analyze any number of systems including cross-platform dependencies and a detailed treatment of the logistics required to support the systems in a defined mission.

  17. Radiology education 2.0--on the cusp of change: part 1. Tablet computers, online curriculums, remote meeting tools and audience response systems.

    Science.gov (United States)

    Bhargava, Puneet; Lackey, Amanda E; Dhand, Sabeen; Moshiri, Mariam; Jambhekar, Kedar; Pandey, Tarun

    2013-03-01

    We are in the midst of an evolving educational revolution. Use of digital devices such as smart phones and tablet computers is rapidly increasing among radiologists who now regularly use them for medical, technical, and administrative tasks. These electronic tools provide a wide array of new tools to the radiologists allowing for faster, more simplified, and widespread distribution of educational material. The utility, future potential, and limitations of some these powerful tools are discussed in this article.

  18. Usability of a novel digital medicine system in adults with schizophrenia treated with sensor-embedded tablets of aripiprazole

    Directory of Open Access Journals (Sweden)

    Peters-Strickland T

    2016-10-01

    Full Text Available Timothy Peters-Strickland,1 Linda Pestreich,1 Ainslie Hatch,2 Shashank Rohatagi,1 Ross A Baker,1 John P Docherty,2 Lada Markovtsova,1 Praveen Raja,3 Peter J Weiden,4 David P Walling5 1Otsuka Pharmaceutical Development & Commercialization, Inc., 2ODH, Inc., Princeton, NJ, 3Proteus Digital Health, Inc., Redwood City, CA, 4Department of Psychiatry, University of Illinois, Chicago, IL, 5CNS Network, LLC, Long Beach, CA, USA Objective: Digital medicine system (DMS is a novel drug–device combination that objectively measures and reports medication ingestion. The DMS consists of medication embedded with an ingestible sensor (digital medicine, a wearable sensor, and software applications. This study evaluated usability of the DMS in adults with schizophrenia rated by both patients and their health care providers (HCPs during 8-week treatment with prescribed doses of digital aripiprazole.Methods: Six US sites enrolled outpatients into this Phase IIa, open-label study (NCT02219009. The study comprised a screening phase, a training phase (three weekly site visits, and a 5-week independent phase. Patients and HCPs independently rated usability of and satisfaction with the DMS.Results: Sixty-seven patients were enrolled, and 49 (73.1% patients completed the study. The mean age (SD of the patients was 46.6 years (9.7 years; the majority of them were male (74.6%, black (76.1%, and rated mildly ill on the Clinical Global Impression – Severity scale (70.1%. By the end of week 8 or early termination, 82.1% (55/67 of patients had replaced the wearable sensor independently or with minimal assistance, based on HCP rating. The patients used the wearable sensor for a mean (SD of 70.7% (24.7% and a median of 77.8% of their time in the trial. The patients contacted a call center most frequently at week 1. At the last visit, 78% (47/60 of patients were somewhat satisfied/satisfied/extremely satisfied with the DMS.Conclusion: A high proportion of patients with

  19. Continuous melt granulation: Influence of process and formulation parameters upon granule and tablet properties.

    Science.gov (United States)

    Monteyne, Tinne; Vancoillie, Jochem; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-10-01

    The pharmaceutical industry has a growing interest in alternative manufacturing models allowing automation and continuous production in order to improve process efficiency and reduce costs. Implementing a switch from batch to continuous processing requires fundamental process understanding and the implementation of quality-by-design (QbD) principles. The aim of this study was to examine the relationship between formulation-parameters (type binder, binder concentration, drug-binder miscibility), process-parameters (screw speed, powder feed rate and granulation temperature), granule properties (size, size distribution, shape, friability, true density, flowability) and tablet properties (tensile strength, friability, dissolution rate) of four different drug-binder formulations using Design of experiments (DOE). Two binders (polyethylene glycol (PEG) and Soluplus®) with a different solid state, semi-crystalline vs amorphous respectively, were combined with two model-drugs, metoprolol tartrate (MPT) and caffeine anhydrous (CAF), both having a contrasting miscibility with the binders. This research revealed that the granule properties of miscible drug-binder systems depended on the powder feed rate and barrel filling degree of the granulator whereas the granule properties of immiscible systems were mainly influenced by binder concentration. Using an amorphous binder, the tablet tensile strength depended on the granule size. In contrast, granule friability was more important for tablet quality using a brittle binder. However, this was not the case for caffeine-containing blends, since these phenomena were dominated by the enhanced compression properties of caffeine Form I, which was formed during granulation. Hence, it is important to gain knowledge about formulation behavior during processing since this influences the effect of process parameters onto the granule and tablet properties.

  20. Carbon Break Even Analysis: Environmental Impact of Tablets in Higher Education

    Directory of Open Access Journals (Sweden)

    Fadi Safieddine

    2016-05-01

    Full Text Available With the growing pace of tablets use and the large focus it is attracting especially in higher education, this paper looks at an important aspect of tablets; their carbon footprint. Studies have suggested that tablets have positive impact on the environment; especially since tablets use less energy than laptops or desktops. Recent manufacturers’ reports on the carbon footprint of tablets have revealed that a significant portion, as much as 80%, of the carbon footprint of tablets comes from production and delivery as opposed to the operational life-cycle of these devices. Thus rending some of previous assumptions about the environmental impact of tablets questionable. This study sets to answer a key question: What is the break-even analysis point when saving on printed paper offsets the carbon footprint of producing and running the tablet in higher education. A review of the literature indicated several examples of tablet models and their carbon emission impact; this is compared to the environmental savings on paper that green courses could produce. The analysis of the carbon break-even point shows that even when considering some of the most efficient and least carbon impact tablets available on the market with a carbon-footprint production of 153Kg CO2e, the break-even point is 81.5 months; referring to 6 years, 9 months and 15 days of use. This exceeds the life-cycle of an average tablet of five years and average degree duration of four years. While tablets still have the least carbon-footprint impact compared to laptops and desktops, to achieve the break-even point of carbon neutral operations this study concludes that manufacturers need to find more environmentally efficient ways of production that would reduce the carbon-footprint product to a level that does not exceed 112.8kg CO2e.

  1. Dissolution Behavior and Content Uniformity of An Improved Tablet Formulation Assayed by Spectrofluorometric and RIA Methods

    Directory of Open Access Journals (Sweden)

    Morteza Rafiee-Tehrani

    1990-06-01

    Full Text Available Digoxin 0.25 mg tablets were manufactured by pregranulation of lactose-fcorn starch with 10% corn starch paste and deposition of solvent on pregranules to make digoxin granules. In the preparation of tablet A, granules of lactose-corn Starch was uniformly moistened with a 5% chloroform-ethanol solution (2:lv/vof digoxin by a simple blending. Tablet B was produced by spray granulation system on which the solvent was sprayed on the granules of lactose-corn starch by utilization of a laboratory size fluidized bed drier (Uniglatt . The content uniformity and dissolution of both tablets were determined by the spectrofluorometric and radio¬immunoassay (RIA method modified for the assay of tablet solutious. One available commercially brand of digoxin tablet (C was included in dissolution study for comparison. For the spectrofluorometric method the technique is based on the fluor-ometric measurenent of the dehydration product of the cardiotonic steroid resulting from its reaction with hydrogen peroxide in concentrated hydrochloric acid. For the RIA method, the filtrate was diluted to theoretical concentration of 2.5 ng/ml."nAliquots of this dilution were then assayed for digoxin content using a commercial digoxin125 I RIA kit. Results from both assay methods were extrapolated to the total tablet content and compared with the labeled amount of 20 individual tablets. All tablet assay results were within the USP standards for the content uniformity and"ndissolution of individual. The individual tablet deviations from labeled amount by RIA method were smaller when compared with the spectrofluorometric method.There was no significant difference between the release of digoxin from three products, and thus it is suggested that the Procedure B could be easily applied for manufacturing"nof digoxin tablets in industrial scales.It was also concluded that,the RIA method could be used for the digoxin tablet determination.

  2. Life-Span Differences in the Uses and Gratifications of Tablets: Implications for Older Adults.

    Science.gov (United States)

    Magsamen-Conrad, Kate; Dowd, John; Abuljadail, Mohammad; Alsulaiman, Saud; Shareefi, Adnan

    2015-11-01

    This study extends Uses and Gratifications theory by examining the uses and gratifications of a new technological device, the tablet computer, and investigating the differential uses and gratifications of tablet computers across the life-span. First, we utilized a six-week tablet training intervention to adapt and extend existing measures to the tablet as a technological device. Next, we used paper-based and online surveys (N=847), we confirmed four main uses of tablets: 1) Information Seeking, 2) Relationship Maintenance, 3) Style, 4) Amusement and Killing time, and added one additional use category 5) Organization. We discovered differences among the five main uses of tablets across the life-span, with older adults using tablets the least overall. Builders, Boomers, GenX and GenY all reported the highest means for information seeking. Finally, we used a structural equation model to examine how uses and gratifications predicts hours of tablet use. The study provides limitations and suggestions for future research and marketers. In particular, this study offers insight to the relevancy of theory as it applies to particular information and communication technologies and consideration of how different periods in the life-span affect tablet motivations.

  3. Development and evaluation of acid-buffering bioadhesive vaginal tablet for mixed vaginal infections.

    Science.gov (United States)

    Alam, Mohd Aftab; Ahmad, Farhan Jalees; Khan, Zeenat Iqbal; Khar, Roop Krishen; Ali, Mushir

    2007-12-14

    An acid-buffering bioadhesive vaginal tablet was developed for the treatment of genitourinary tract infections. From the bioadhesion experiment and release studies it was found that polycarbophil and sodium carboxymethylcellulose is a good combination for an acid-buffering bioadhesive vaginal tablet. Sodium monocitrate was used as a buffering agent to provide acidic pH (4.4), which is an attribute of a healthy vagina. The effervescent mixture (citric acid and sodium bicarbonate) along with a superdisintegrant (Ac-Di-sol) was used to enhance the swellability of the bioadhesive tablet. The drugs clotrimazole (antifungal) and metronidazole (antiprotozoal as well as an antibacterial) were used in the formulation along with Lactobacillus acidophilus spores to treat mixed vaginal infections. From the ex vivo retention study it was found that the bioadhesive polymers hold the tablet for more than 24 hours inside the vaginal tube. The hardness of the acid-buffering bioadhesive vaginal tablet was optimized, at 4 to 5 kg hardness the swelling was found to be good and the cumulative release profile of the developed tablet was matched with a marketed conventional tablet (Infa-V). The in vitro spreadability of the swelled tablet was comparable to the marketed gel. In the in vitro antimicrobial study it was found that the acid-buffering bioadhesive tablet produces better antimicrobial action than marketed intravaginal drug delivery systems (Infa-V, Candid-V and Canesten 1).

  4. FORMULATION AND EVALUATION OF EFFERVESCENT TABLETS OF ACECLOFENAC

    Directory of Open Access Journals (Sweden)

    Palanisamy P

    2011-12-01

    Full Text Available Recently, fast-dissolving drug delivery systems have started gaining popularity and acceptance as new drug delivery systems, because they are easy to administer and lead to better patient compliance. Usually, elderly people experience difficulty in swallowing the tablet. Aceclofenac is a NSAID which has greater inhibitory action against the inducible form of cyclooxygenase (COX-2 which is implicated in the inflammatory response against the constitutive form of this enzyme (COX-1 inhibition. The aim of this study was to formulate Effervescent tablet with sufficient mechanical integrity and to achieve faster disintegration in the water. Effervescent tablets are uncoated tablets that generally contain acid substances and carbonates or bicarbonates and which react rapidly in the presence of water by releasing carbon dioxide. They are intended to be dissolved or dispersed in water before use. Effervescent compositions in the form of tablets comprising a therapeutic agent, a granulating agent, a micro particulate effervescent component and an effervescent system which dissolve rapidly in water to yield an effervescent solution containing a completely dissolved therapeutic agent and a process for their preparation.

  5. Near-infrared spectroscopy (NIRS) and chemometric analysis of Malaysian and UK paracetamol tablets: a spectral database study.

    Science.gov (United States)

    Said, Mazlina M; Gibbons, Simon; Moffat, Anthony C; Zloh, Mire

    2011-08-30

    The influx of medicines from different sources into healthcare systems of developing countries presents a challenge to monitor their origin and quality. The absence of a repository of reference samples or spectra prevents the analysis of tablets by direct comparison. A set of paracetamol tablets purchased in Malaysian pharmacies were compared to a similar set of sample purchased in the UK using near-infrared spectroscopy (NIRS). Additional samples of products containing ibuprofen or paracetamol in combination with other actives were added to the study as negative controls. NIR spectra of the samples were acquired and compared by using multivariate modeling and classification algorithms (PCA/SIMCA) and stored in a spectral database. All analysed paracetamol samples contained the purported active ingredient with only 1 out of 20 batches excluded from the 95% confidence interval, while the negative controls were clearly classified as outliers of the set. Although the substandard products were not detected in the purchased sample set, our results indicated variability in the quality of the Malaysian tablets. A database of spectra was created and search methods were evaluated for correct identification of tablets. The approach presented here can be further developed as a method for identifying substandard pharmaceutical products. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. A systems biology-based approach to uncovering the molecular mechanisms underlying the effects of dragon's blood tablet in colitis, involving the integration of chemical analysis, ADME prediction, and network pharmacology.

    Science.gov (United States)

    Xu, Haiyu; Zhang, Yanqiong; Lei, Yun; Gao, Xiumei; Zhai, Huaqiang; Lin, Na; Tang, Shihuan; Liang, Rixin; Ma, Yan; Li, Defeng; Zhang, Yi; Zhu, Guangrong; Yang, Hongjun; Huang, Luqi

    2014-01-01

    Traditional Chinese medicine (TCM) is one of the oldest East Asian medical systems. The present study adopted a systems biology-based approach to provide new insights relating to the active constituents and molecular mechanisms underlying the effects of dragon's blood (DB) tablets for the treatment of colitis. This study integrated chemical analysis, prediction of absorption, distribution, metabolism, and excretion (ADME), and network pharmacology. Firstly, a rapid, reliable, and accurate ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry method was employed to identify 48 components of DB tablets. In silico prediction of the passive absorption of these compounds, based on Caco-2 cell permeability, and their P450 metabolism enabled the identification of 22 potentially absorbed components and 8 metabolites. Finally, networks were constructed to analyze interactions between these DB components/metabolites absorbed and their putative targets, and between the putative DB targets and known therapeutic targets for colitis. This study provided a great opportunity to deepen the understanding of the complex pharmacological mechanisms underlying the effects of DB in colitis treatment.

  7. A systems biology-based approach to uncovering the molecular mechanisms underlying the effects of dragon's blood tablet in colitis, involving the integration of chemical analysis, ADME prediction, and network pharmacology.

    Directory of Open Access Journals (Sweden)

    Haiyu Xu

    Full Text Available Traditional Chinese medicine (TCM is one of the oldest East Asian medical systems. The present study adopted a systems biology-based approach to provide new insights relating to the active constituents and molecular mechanisms underlying the effects of dragon's blood (DB tablets for the treatment of colitis. This study integrated chemical analysis, prediction of absorption, distribution, metabolism, and excretion (ADME, and network pharmacology. Firstly, a rapid, reliable, and accurate ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry method was employed to identify 48 components of DB tablets. In silico prediction of the passive absorption of these compounds, based on Caco-2 cell permeability, and their P450 metabolism enabled the identification of 22 potentially absorbed components and 8 metabolites. Finally, networks were constructed to analyze interactions between these DB components/metabolites absorbed and their putative targets, and between the putative DB targets and known therapeutic targets for colitis. This study provided a great opportunity to deepen the understanding of the complex pharmacological mechanisms underlying the effects of DB in colitis treatment.

  8. 3D Printing Factors Important for the Fabrication of Polyvinylalcohol Filament-Based Tablets.

    Science.gov (United States)

    Tagami, Tatsuaki; Fukushige, Kaori; Ogawa, Emi; Hayashi, Naomi; Ozeki, Tetsuya

    2017-01-01

    Three-dimensional (3D) printers have been applied in many fields, including engineering and the medical sciences. In the pharmaceutical field, approval of the first 3D-printed tablet by the U.S. Food and Drug Administration in 2015 has attracted interest in the manufacture of tablets and drugs by 3D printing techniques as a means of delivering tailor-made drugs in the future. In current study, polyvinylalcohol (PVA)-based tablets were prepared using a fused-deposition-modeling-type 3D printer and the effect of 3D printing conditions on tablet production was investigated. Curcumin, a model drug/fluorescent marker, was loaded into PVA-filament. We found that several printing parameters, such as the rate of extruding PVA (flow rate), can affect the formability of the resulting PVA-tablets. The 3D-printing temperature is controlled by heating the print nozzle and was shown to affect the color of the tablets and their curcumin content. PVA-based infilled tablets with different densities were prepared by changing the fill density as a printing parameter. Tablets with lower fill density floated in an aqueous solution and their curcumin content tended to dissolve faster. These findings will be useful in developing drug-loaded PVA-based 3D objects and other polymer-based articles prepared using fused-deposition-modeling-type 3D printers.

  9. TSH-Based Protocol, Tablet Instability, and Absorption Effects on L-T4 Bioequivalence

    Science.gov (United States)

    DiStefano, Joseph J.

    2009-01-01

    Background FDA Guidance for pharmacokinetic (PK) testing of levothyroxine (L-T4) for interbrand bioequivalence has evolved recently. Concerns remain about efficacy and safety of the current protocol, based on PK analysis following supraphysiological L-T4 dosing in euthyroid volunteers, and recent recalls due to intrabrand manufacturing problems also suggest need for further refinement. We examine these interrelated issues quantitatively, using simulated what-if scenarios testing efficacy of a TSH-based protocol and tablet stability and absorption, to enhance precision of L-T4 bioequivalence methods. Methods We use an updated simulation model of human thyroid hormone regulation quantified and validated from data that span a wide range of normal and abnormal thyroid system function. Bioequivalence: We explored a TSH-based protocol, using normal replacement dosing in simulated thyroidectomized patients, switching brands after 8 weeks of full replacement dosing. We simulated effects of tablet potency differences and intestinal absorption differences on predicted plasma TSH, T4, and triiodothyronine (T3) dynamics. Stability: We simulated effects of potency decay and lot-by-lot differences in realistic scenarios, using actual tablet potency data spanning 2 years, comparing the recently reduced 95–105% FDA-approved potency range with the original 90–110% range. Results A simulated decrease as small as 10–15% in L-T4 or its absorption generated TSH concentrations outside the bioequivalence target range (0.5–2.5 mU/L TSH), whereas T3 and T4 plasma levels were maintained normal. For a 25% reduction, steady-state TSH changed 300% (from 1.5 to 6 mU/L) compared with <25% for both T4 and T3 (both within their reference ranges). Stability: TSH, T4, and T3 remained within normal ranges for most potency decay scenarios, but tablets of the same dose strength and brand were not bioequivalent between lots and between fresh and near-expired tablets. Conclusions A

  10. FORMULATION AND EVALUATION OF COLON SPECIFIC MATRIX AND COATED TABLET OF METRONIDAZOLE

    Directory of Open Access Journals (Sweden)

    M. Praveen Kumar

    2011-09-01

    Full Text Available Targeting of drugs to the colon by the oral route could be achieved by different approaches including matrix and coated systems, for which the drug release is controlled by the gastrointestinal pH, transit times and intestinal flora. The method by which the drug release will be triggered by the colonic flora appears to be more interesting with regard to the selectivity. Metronidazole is only used antibiotics which can be used in colonic diseases. Matrix tablets were prepared by mixtures of Pectin and Guar gum, in which Metronidazole was selected as model drug. Six Matrix (F-I to VI and coated (F VII to XII tablet formulations of Metronidazole were prepared by different mixtures of pectin and guar gum then coated with Eudragit RS 100, for coated tablets. The results of drug release studies, performed according to the USP paddle method by using 0.1N hydrochloric acid for 2 hrs, pH 7.4 phosphate buffer for 3 hrs and pH 6.8 phosphate buffer for 24 hrs. And In vitro dissolution study for metronidazole tablets in Rat cecal content were performed. Matrix tablets of guar gum with metronidazole in the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 83%, 63% and 55% respectively. Pectin in the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 100%, 95% and 82% respectively. Coated tablets of guar gum with metronidazole in the ratio the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 96%, 60% and 52% respectively. Pectin in the ratio of 1:1, 1:2 and 1:3 shows percent drug release after 24 hrs as 97%, 99% and 95% respectively. All these batches in first two hours i.e. pH 1.2 hydrochloric acid shows very neglible release, then it showed slight increase in pH 7.4 Phosphate Buffer. Drug release up to 5 hours but it showed high and fast increase in drug release from 6th hour in pH 6.8 Phosphate buffer, as it enters in colonic pH. So natural polymers are most cheap and suitable for colonic drug

  11. ECO-BIOLOGICAL SYSTEM MODELING

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    T. I. Burak

    2015-01-01

    Full Text Available The methodology for computer modeling of complex eco-biological models is presented in this paper. It is based on system approach of J. Forrester. Developed methodology is universal for complex ecological and biological systems. Modeling algorithm considers specialties of eco-biological systems and shows adequate and accurate results in practice. 

  12. Students' Acceptance of Tablet PCs in the Classroom

    Science.gov (United States)

    Ifenthaler, Dirk; Schweinbenz, Volker

    2016-01-01

    In recent years digital technologies, such as tablet personal computers (TPCs), have become an integral part of a school's infrastructure and are seen as a promising way to facilitate students' learning processes. This study empirically tested a theoretical model derived from the technology acceptance model containing key constructs developed in…

  13. Students' Acceptance of Tablet PCs and Implications for Educational Institutions

    Science.gov (United States)

    El-Gayar, Omar; Moran, Mark; Hawkes, Mark

    2011-01-01

    This research develops and empirically tests a factor model for understanding college students' acceptance of Tablet PC (TPC) as a means to forecast, explain, and improve their usage pattern in education. The analysis involved more than 230 students from a regional Midwestern institution. Overall, our model exhibited a good fit with the data and…

  14. Characterization of omega-3 tablets.

    Science.gov (United States)

    Vestland, Tina Lien; Jacobsen, Øyvind; Sande, Sverre Arne; Myrset, Astrid Hilde; Klaveness, Jo

    2016-04-15

    Omega-3 nutraceuticals are extensively used as health supplements worldwide. Various administration forms for delivery of omega-3 are available. However, the niche omega-3 tablets have so far remained unexplored. In this work tablets containing 25-40% (w/w) omega-3 oil as triglycerides or ethyl esters were prepared utilizing a direct compaction grade powder with β-cyclodextrin as encapsulating agent. It was found that powders with up to 35% (w/w) triglyceride oil and 30% (w/w) ethyl ester oil, respectively, can be directly compressed into tablets of excellent quality. Physical properties of omega-3 containing powders and tablets are described. The powder X-ray diffractograms of the powders and crushed tablets show evidence of the formation of new crystalline phases not present in β-cyclodextrin. In addition, (1)H NMR data suggest that the ethyl esters form inclusion complexes with β-cyclodextrin. Compaction of other, commercially available, omega-3 powders was performed as a comparison and deemed unsuccessful.

  15. Dissolution and permeation characteristics of artemether tablets ...

    African Journals Online (AJOL)

    and permeation characteristics of the formulations were studied using USP methods. Results: Tablets .... Table 2: Physical properties of the artemether tablets. Batch. Code. CS (kgf) ..... metformin using prosopis gum with antidiabetic potential.

  16. Fed and fasted state gastro-intestinal in vitro lipolysis: In vitro in vivo relations of a conventional tablet, a SNEDDS and a solidified SNEDDS.

    Science.gov (United States)

    Christophersen, Philip Carsten; Christiansen, Martin Lau; Holm, Rene; Kristensen, Jakob; Jacobsen, Jette; Abrahamsson, Bertil; Müllertz, Anette

    2014-06-16

    The present study aims at evaluating the ability of a gastro-intestinal in vitro lipolysis model to predict the performance of two lipid formulations and a conventional tablet containing a poorly soluble drug, cinnarizine, in dogs, both in the fasted and fed state. A self-nano-emulsifying drug delivery system (SNEDDS) was either dosed in a hard gelatin capsule (SNEDDS-C) or loaded onto a porous tablet core (SNEDDS-T) and compared to a marketed conventional tablet (Conv) in an in vitro lipolysis model. The model simulates the digestion in the stomach and intestine during either the fasted or the fed state. Whole fat milk (3.5%) was used in the fed state model to mimic the dynamic lipolysis events after ingestion of food. The results were compared to a dog study published in this issue. In the fasted state in vitro lipolysis model, the amount of solubilized cinnarizine decreased in the order SNEDDS-C>SNEDDS-T>Conv, which correlated well with the in vivo bioavailability. In the fed state in vitro lipolysis model, cinnarizine was solubilized to the same degree for all formulations. Compared to the fasted state model, only the performance of the conventional tablet was improved, indicating food effect. This correlated with the in vivo study, where the tablet was the only formulation with a significant food effect. The fasted state model correlated well with the in vivo results and although the fed state model did not accurately predict the fed state in vivo results, it could predict which formulation that would exhibit a food effect.

  17. Evaluation of quick disintegrating calcium carbonate tablets

    OpenAIRE

    Fausett, Hector; Gayser, Charles; Dash, Alekha K.

    2000-01-01

    The purpose of this investigation was to develop a rapidly disintegrating calcium carbonate (CC) tablet by direct compression and compare it with commercially available calcium tablets. CC tablets were formulated on a Carver press using 3 different forms of CC direct compressed granules (Cal-Carb 4450®, Cal-Carb 4457®, and Cal-Carb 4462®). The breaking strength was measured using a Stokes-Monsanto hardness tester. The disintegration and dissolution properties of the tablets were studied using...

  18. A new experimental design method to optimize formulations focusing on a lubricant for hydrophilic matrix tablets.

    Science.gov (United States)

    Choi, Du Hyung; Shin, Sangmun; Khoa Viet Truong, Nguyen; Jeong, Seong Hoon

    2012-09-01

    A robust experimental design method was developed with the well-established response surface methodology and time series modeling to facilitate the formulation development process with magnesium stearate incorporated into hydrophilic matrix tablets. Two directional analyses and a time-oriented model were utilized to optimize the experimental responses. Evaluations of tablet gelation and drug release were conducted with two factors x₁ and x₂: one was a formulation factor (the amount of magnesium stearate) and the other was a processing factor (mixing time), respectively. Moreover, different batch sizes (100 and 500 tablet batches) were also evaluated to investigate an effect of batch size. The selected input control factors were arranged in a mixture simplex lattice design with 13 experimental runs. The obtained optimal settings of magnesium stearate for gelation were 0.46 g, 2.76 min (mixing time) for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The optimal settings for drug release were 0.33 g, 7.99 min for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The exact ratio and mixing time of magnesium stearate could be formulated according to the resulting hydrophilic matrix tablet properties. The newly designed experimental method provided very useful information for characterizing significant factors and hence to obtain optimum formulations allowing for a systematic and reliable experimental design method.

  19. A novel rapid quantitative analysis of drug migration on tablets using laser induced breakdown spectroscopy.

    Science.gov (United States)

    Yokoyama, Makoto; Tourigny, Martine; Moroshima, Kenji; Suzuki, Junsuke; Sakai, Miyako; Iwamoto, Kiyoshi; Takeuchi, Hirofumi

    2010-11-01

    There have been few reports wherein drug migration from the interior to the surface of a tablet has been analyzed quantitatively until now. In this paper, we propose a novel, rapid, quantitative analysis of drug migration in tablets using laser induced breakdown spectroscopy (LIBS). To evaluate drug migration, model tablets containing nicardipine hydrochloride as active pharmaceutical ingredient (API) were prepared by a conventional wet granulation method. Since the color of this API is pale yellow and all excipients are white, we can observe the degree of drug migration by visual inspection in these model tablets. In order to prepare tablets with different degrees of drug migration, the temperature of the drying process after tableting was varied between 50 to 80 °C. Using these manifold tablets, visual inspection, Fourier transform (FT)-IR mapping and LIBS analysis were carried out to evaluate the drug migration in the tablets. While drug migration could be observed using all methods, only LIBS analysis could provide quantitative analysis wherein the average LIBS intensity was correlated with the degree of drug migration obtained from the drying temperature. Moreover, in this work, we compared the sample preparation, data analysis process and measurement time for visual inspection, FT-IR mapping and LIBS analysis. The results of the comparison between these methods demonstrated that LIBS analysis is the simplest and the fastest method for migration monitoring. From the results obtained, we conclude that LIBS analysis is one of most useful process analytical technology (PAT) tools to solve the universal migration problem.

  20. Preparation and scale up of extended-release tablets of bromopride

    Directory of Open Access Journals (Sweden)

    Guilherme Neves Ferreira

    2014-04-01

    Full Text Available Reproducibility of the tablet manufacturing process and control of its pharmaceutics properties depends on the optimization of formulation aspects and process parameters. Computer simulation such as Design of Experiments (DOE can be used to scale up the production of this formulation, in particular for obtaining sustained-release tablets. Bromopride formulations are marketed in the form of extended-release pellets, which makes the product more expensive and difficult to manufacture. The aim of this study was to formulate new bromopride sustained release formulations as tablets, and to develop mathematical models to standardize the scale up of this formulation, controlling weight and hardness of the tablets during manufacture according to the USP 34th edition. DOE studies were conducted using Minitab(tm software. Different excipient combinations were evaluated in order to produce bromopride sustained-release matrix tablets. In the scale-up study, data were collected and variations in tableting machine parameters were measured. Data were processed by Minitab(tm software, generating mathematical equations used for prediction of powder compaction behavior, according to the settings of the tableting machine suitable for scale-up purposes. Bromopride matrix tablets with appropriate characteristics for sustained release were developed. The scale-up of the formulation with the most suitable sustained release profile was established by using mathematical models, indicating that the formulation can be a substitute for the pellets currently marketed.

  1. Mathematical System Theory and System Modeling

    OpenAIRE

    1980-01-01

    Choosing models related effectively to the questions to be addressed is a central issue in the craft of systems analysis. Since the mathematical description the analyst chooses constrains the types of issues he candeal with, it is important for these models to be selected so as to yield limitations that are acceptable in view of the questions the systems analysis seeks to answer. In this paper, the author gives an overview of the central issues affecting the question of model choice. To ...

  2. Preparation of fluconazole buccal tablet and influence of formulation expedients on its properties

    Institute of Scientific and Technical Information of China (English)

    MOHAMED Saifulla P; MUZZAMMIL Shariff; PRAMOD Kumar TM

    2011-01-01

    The aim of present study was to prepare buccal tablets of fluconazole for oral candidiasis.The dosage forms were designed to release the drug above the minimum inhibitory concentration for prolonged period of time so as to reduce the frequency of administration and to overcome the side effects of systemic treatment.The buccal tablets were prepared by using Carbopol 71G and Noveon AA-1 by direct compression method.Microcrystalline cellulose was used as the filler and its effect was also studied.The prepared dosage forms were evaluated for physicochemical properties,in vitro release studies and mueoadhesive properties using sheep buccal mucosa as a model tissue.Tablets containing 50% of polymers(Carbopol & Noveon)were found to be the best with moderate swelling along with favorable bioadhesion force,residence time and in vitro drug release.The in vitro drug release studies revealed that drug released for 8 h,which in turn may reduce dosing frequency and improved patient compliance in oral candidiasis patients.

  3. Quality by design approach for formulation development: a case study of dispersible tablets.

    Science.gov (United States)

    Charoo, Naseem A; Shamsher, Areeg A A; Zidan, Ahmed S; Rahman, Ziyaur

    2012-02-28

    The focus of the current investigations was to apply quality by design (QbD) approach to the development of dispersible tablets. Critical material and process parameters are linked to the critical quality attributes of the product. Variability is reduced by product and process understanding which translates into quality improvement, risk reduction and productivity enhancement. The risk management approach further leads to better understanding of the risks, ways to mitigate them and control strategy is proposed commensurate with the level of the risk. Design space in combination with pharmaceutical quality management system provide for flexible regulatory approaches with opportunity for continuous improvement that benefit patient and manufacturer alike. The development of dispersible tablet was proposed in the current study through a QbD paradigm for a better patient compliance and product quality. The quality target product profile of a model biopharmaceutical class II drug was identified. Initial risk analysis led to the identification of the critical quality attributes. Physicochemical characterization and compatibility studies of the drug with commonly used excipients were performed. Experiments were designed with focus on critical material and process attributes. Design space was identified and risk factors for all the possible failure modes were below critical levels after the implementation of control strategy. Compliance to the design space provides an opportunity to release batches in a real time. In conclusion, QbD tools together with risk and quality management tools provided an effective and efficient paradigm to build the quality into dispersible tablet.

  4. Stability of benzocaine formulated in commercial oral disintegrating tablet platforms.

    Science.gov (United States)

    Köllmer, Melanie; Popescu, Carmen; Manda, Prashanth; Zhou, Leon; Gemeinhart, Richard A

    2013-12-01

    Pharmaceutical excipients contain reactive groups and impurities due to manufacturing processes that can cause decomposition of active drug compounds. The aim of this investigation was to determine if commercially available oral disintegrating tablet (ODT) platforms induce active pharmaceutical ingredient (API) degradation. Benzocaine was selected as the model API due to known degradation through ester and primary amino groups. Benzocaine was either compressed at a constant pressure, 20 kN, or at pressure necessary to produce a set hardness, i.e., where a series of tablets were produced at different compression forces until an average hardness of approximately 100 N was achieved. Tablets were then stored for 6 months under International Conference on Harmonization recommended conditions, 25°C and 60% relative humidity (RH), or under accelerated conditions, 40°C and 75% RH. Benzocaine degradation was monitored by liquid chromatography-mass spectrometry. Regardless of the ODT platform, no degradation of benzocaine was observed in tablets that were kept for 6 months at 25°C and 60% RH. After storage for 30 days under accelerated conditions, benzocaine degradation was observed in a single platform. Qualitative differences in ODT platform behavior were observed in physical appearance of the tablets after storage under different temperature and humidity conditions.

  5. Interaction With PC Tablets And Possible Emotional Responses

    Directory of Open Access Journals (Sweden)

    Emy Agren

    2015-08-01

    Full Text Available The remarkable developments in mobile-based technologies have brought prominent impacts on human life style. Today life is running on mobile electronic devices smart phones tablets gaming devices and video-players. Generally the users acquaint with the features and properties of products after emotionally and physically interacting with the devices. The interaction in return influencing our moods depending on the feelings the technology creates. The focus of this study lays on the uses of tablets or also called PC tablets and its effects on its users emotional responses. To discover possible emotional responses with the tablets the data in this work were collected through a survey questionnaire from participants belongs to various backgrounds age groups and genders. The model of emotions was adopted in order to classify the emotional responses.The study has found that during or after the interaction with the tablets the users may get positive or negative emotional responses of a different kind. The users mood can also be affected by awakening such emotional feelings as happiness sadness frustration etc.

  6. FORMULATION AND EVALUATION OF FLOATING TABLETS OF TIZANIDINE HYDROCHLORIDE

    Directory of Open Access Journals (Sweden)

    Adimoolam Senthil

    2011-08-01

    Full Text Available The objective of the present investigation was to develop floating matrix tablets of tizanidine hydrochloride for prolongation of gastric residence time in order to overcome its low bioavailability (34–40% and short biological half life (4.2 h. Tizanidine hydrochloride floating tablets were prepared by the direct compression method, using different viscosity grades of hydroxypropylmethylcellulose (HPMC K4M and K15M. Tizanidine hydrochloride is an orally administered prokinetic agent that facilitates or restores motility throughout the length of the gastrointestinal tract. Tablets were evaluated for various physical parameters and floating properties. Further, tablets were studied for in-vitro drug release characteristics in 12 hours. Drug release from floating matrix tablets was sustained over 12 h with buoyant properties. DSC study revealed that there was no drug and excipient interaction. Based on the release kinetics, all formulations best fitted the Higuchi, first-order model and non-Fickian as the mechanism of drug release. The optimized formulation (F9 released 75% of drug at the end of 10 hours by in-vitro release study.

  7. Automated visual inspection of imprinted pharmaceutical tablets

    Science.gov (United States)

    Bukovec, Marko; Špiclin, Žiga; Pernuš, Franjo; Likar, Boštjan

    2007-09-01

    This paper is on automated visual inspection of tablets that may, in contrast to manual tablet sorting, provide objective and reproducible tablet quality assurance. Visual inspection of the ever-increasing numbers of produced imprinted tablets, regulatory enforced for unambiguous identification of active ingredients and dosage strength of each tablet, is especially demanding. The problem becomes more tractable by incorporating some a priori knowledge of the imprint shape and/or appearance. For this purpose, we consider two alternative automated tablet defect detection methods. The geometrical method, incorporating geometrical a priori knowledge of the imprint shape, enables specific inspection of the imprinted and non-imprinted tablet surface, while the statistical method exploits statistical a priori knowledge of tablet surface appearance, derived from a training image database. The two methods were evaluated on a large tablet image database, consisting of 3445 images of four types of imprinted tablets, with and without typical production defects. A 'gold standard' for testing the performances of the two inspection methods was established by manually classifying the tablets into good and five defective classes. The results, obtained by ROC (receiver operating characteristics) analysis, indicate that the statistical method yields better defect detection sensitivity and specificity than the geometrical method. Both presented image analysis methods are quite general and promising tools for automated visual inspection of imprinted pharmaceutical tablets.

  8. Touch Screen Tablets and Emergent Literacy

    Science.gov (United States)

    Neumann, Michelle M.; Neumann, David L.

    2014-01-01

    The use of touch screen tablets by young children is increasing in the home and in early childhood settings. The simple tactile interface and finger-based operating features of tablets may facilitate preschoolers' use of tablet application software and support their educational development in domains such as literacy. This article reviews…

  9. 21 CFR 520.1310 - Marbofloxacin tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Marbofloxacin tablets. 520.1310 Section 520.1310... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1310 Marbofloxacin tablets. (a) Specifications. Each tablet contains 25, 50, 100, or 200 milligrams (mg) marbofloxacin....

  10. Portable Tablets in Science Museum Learning: Options and Obstacles

    Science.gov (United States)

    Gronemann, Sigurd Trolle

    2016-12-01

    Despite the increasing use of portable tablets in learning, their impact has received little attention in research. In five different projects, this media-ethnographic and design-based analysis of the use of portable tablets as a learning resource in science museums investigates how young people's learning with portable tablets matches the intentions of the museums. By applying media and information literacy (MIL) components as analytical dimensions, a pattern of discrepancies between young people's expectations, their actual learning and the museums' approaches to framing such learning is identified. It is argued that, paradoxically, museums' decisions to innovate by introducing new technologies, such as portable tablets, and new pedagogies to support them conflict with many young people's traditional ideas of museums and learning. The assessment of the implications of museums' integration of portable tablets indicates that in making pedagogical transformations to accommodate new technologies, museums risk opposing didactic intention if pedagogies do not sufficiently attend to young learners' systemic expectations to learning and to their expectations to the digital experience influenced by their leisure use.

  11. Portable Tablets in Science Museum Learning: Options and Obstacles

    Science.gov (United States)

    Gronemann, Sigurd Trolle

    2017-06-01

    Despite the increasing use of portable tablets in learning, their impact has received little attention in research. In five different projects, this media-ethnographic and design-based analysis of the use of portable tablets as a learning resource in science museums investigates how young people's learning with portable tablets matches the intentions of the museums. By applying media and information literacy (MIL) components as analytical dimensions, a pattern of discrepancies between young people's expectations, their actual learning and the museums' approaches to framing such learning is identified. It is argued that, paradoxically, museums' decisions to innovate by introducing new technologies, such as portable tablets, and new pedagogies to support them conflict with many young people's traditional ideas of museums and learning. The assessment of the implications of museums' integration of portable tablets indicates that in making pedagogical transformations to accommodate new technologies, museums risk opposing didactic intention if pedagogies do not sufficiently attend to young learners' systemic expectations to learning and to their expectations to the digital experience influenced by their leisure use.

  12. The determination of the mechanical strength of tablets of different shapes.

    Science.gov (United States)

    Davies, Peter N; Worthington, Harry E C; Podczeck, Fridrun; Newton, J Michael

    2007-08-01

    The aim of the study was to investigate the influence of the platen design, on the evaluation of the mechanical strength of tablets of different shapes in terms of the potential of ensuring reproducible failure mechanisms and deriving their tensile strength. Tablets which were circular, square or hexagonal in shape were prepared at a range of formation pressures each from microcrystalline cellulose (Avicel PH102), a direct compression anhydrous beta-lactose (DCL 21) and dicalcium phosphate dihydrate (Emcompress) with a reciprocating single punch tablet machine. The mechanical strength of the tablets has been determined with a three-point bending test and by applying a diametral load across the edges of the tablets with platens of different designs. Many of the tablets tested in three-point bending did not fail in tension. However, with platens to which semi-circular rods of radius 3.0mm were attached and vertically aligned, a test procedure was provided with which a wide range of tablets tested failed in tension, i.e., split into two halves. Where this occurred it was possible to calculate the tensile strength from the breaking load. Although the value of the tensile strength obtained with such platens was generally lower than that obtained for circular tablets when flat platens were used, the ability to be able to use this new configuration for all the tablet shapes provided a practical system for a range of tablet shapes. The tablets of the three shapes tested here were found to have equivalent values for the tensile strength when formed at the same compaction pressure for the three materials tested.

  13. Supporting Tablet Configuration, Tracking, and Infection Control Practices in Digital Health Interventions: Study Protocol

    Science.gov (United States)

    Furberg, Robert D; Zulkiewicz, Brittany A; Hudson, Jordan P; Taylor, Olivia M; Lewis, Megan A

    2016-01-01

    Background Tablet-based health care interventions have the potential to encourage patient care in a timelier manner, allow physicians convenient access to patient records, and provide an improved method for patient education. However, along with the continued adoption of tablet technologies, there is a concomitant need to develop protocols focusing on the configuration, management, and maintenance of these devices within the health care setting to support the conduct of clinical research. Objective Develop three protocols to support tablet configuration, tablet management, and tablet maintenance. Methods The Configurator software, Tile technology, and current infection control recommendations were employed to develop three distinct protocols for tablet-based digital health interventions. Configurator is a mobile device management software specifically for iPhone operating system (iOS) devices. The capabilities and current applications of Configurator were reviewed and used to develop the protocol to support device configuration. Tile is a tracking tag associated with a free mobile app available for iOS and Android devices. The features associated with Tile were evaluated and used to develop the Tile protocol to support tablet management. Furthermore, current recommendations on preventing health care–related infections were reviewed to develop the infection control protocol to support tablet maintenance. Results This article provides three protocols: the Configurator protocol, the Tile protocol, and the infection control protocol. Conclusions These protocols can help to ensure consistent implementation of tablet-based interventions, enhance fidelity when employing tablets for research purposes, and serve as a guide for tablet deployments within clinical settings. PMID:27350013

  14. SOME CUNEIFORM TABLETS IN JERUSALEM

    Institute of Scientific and Technical Information of China (English)

    Wu; Yuhong

    2014-01-01

    <正>During the four and half months of my staying at the Albright Institute of Archaeological Research in Jerusalem and in the Hebrew University(01.12.2013–13.04.2014),I had the chance to read and study some unpublished cuneiform tablets.Here,I would like to make a small contribution to the work of publishing the precious information hidden in the cuneiform tablets from ancient Mesopotamia,and hope that some colleagues can give some improved reading to

  15. Development of Corn Starch-Neusilin UFL2 Conjugate as Tablet Superdisintegrant: Formulation and Evaluation of Fast Disintegrating Tablets

    Directory of Open Access Journals (Sweden)

    Prateek Juneja

    2014-01-01

    Full Text Available In the present study, corn Starch-Neusilin UFL2 conjugates were prepared by physical, chemical, and microwave methods with the aim of using the conjugates as tablet superdisintegrant. Various powder tests, namely, angle of repose, bulk density, tapped density, Hausner’s ratio, Carr’s index, swelling index, and powder porosity were conducted on the samples. The conjugates were characterized by ATR-FTIR, XRD, DSC, and SEM techniques. Heckel and Kawakita models were applied to carry out compression studies for the prepared conjugates. Fast disintegrating tablets of domperidone were prepared using corn starch and corn Starch-Neusilin UFL2 conjugates as tablet superdisintegrants in different concentrations. Conjugates were found to possess good powder flow and tabletting properties. Heckel analysis indicated that the conjugates prepared by microwave method showed the slowest onset of plastic deformation while Kawakita analysis indicated that the conjugates prepared by microwave method exhibited the highest amount of total plastic deformation. The study revealed that the corn Starch-Neusilin UFL2 conjugates possess improved powder flow properties and could be a promising superdisintegrant for preparing fast disintegrating tablet. Also, the results sugessted that the microwave method was found to be most effective for the preparation of corn Starch-Neusilin UFL2 conjugates.

  16. DEVELOPMENT AND EVALUATION OF MUCOADHESIVE BUCCAL TABLETS OF SALBUTAMOL SULPHATE

    Directory of Open Access Journals (Sweden)

    Arya R. K

    2011-01-01

    Full Text Available Prime object of present study was to develop and evaluate mucoadhesive tablets of Salbutamol Sulphate by non aqueous granulation of polymers HPMC K-4M (Hydroxypropyl Methyl Cellulose and Chitosan in different ratios (1:1. 1:2 & 2:1. The tablets were evaluated for weight variation, hardness, thickness, drug content uniformity, mucoadhesion and swelling index. Swelling index of batches containing more HPMC K-4M was greater than that of containing less HPMC K-4M. In vitro bioadhesive strength studies showed that tablets containing more HPMC K-4M were excellent in bioadhesive nature. The in-vitro drug release was studied in phosphate buffer (pH 6.8. And all batches were subjected to release kinetics model fitting.

  17. Preparation and evaluation of gastroretentive floating tablets of acyclovir.

    Science.gov (United States)

    Garg, Rajeev; Gupta, G D

    2009-10-01

    The present study performed by preparation and evaluation of floating tablets of Acyclovir as model drug for prolongation of gastric residence time. Floating effervescent tablets were formulated by various materials like hydroxypropyl methylcellulose K 4M, K 15M, psyllium husk, swelling agent as crospovidone and microcrystalline cellulose and gas generating agent like sodium bicarbonate and citric acid and evaluated for floating properties, swelling characteristics and in vitro drug release studies. Floating noneffervescent tablets were prepared by polypropylene foam powder and different matrix forming polymers like HPMC K 4M, Carbopol 934P, xanthan gum and sodium alginate. In vitro drug release studies were performed and drug release kinetics evaluated using the linear regression method was found to follow both the Higuchi and the Korsmeyer and Peppas equation. The drug release mechanism was found fickian type in most of the formulations.

  18. 姜百胃炎片对幽门螺杆菌感染模型小鼠的干预作用%Effect of Jiangbai Weiyan Tablets on Helicobacter Pylori Infected Mouse Model

    Institute of Scientific and Technical Information of China (English)

    陈方挺; 王建平; 徐颖颖; 单海丽; 傅旭春; 白海波

    2016-01-01

    目的:观察姜百胃炎片对幽门螺杆菌(Hp)感染模型小鼠体内抑菌作用。方法选用Hp SS1菌株,对实验小鼠(C57BL/6小鼠和BALB/c小鼠)以NaHCO3和混合抗生素预处理、灌胃菌液的方法建立Hp感染小鼠模型。Hp感染成模小鼠随机分成模型组、三联治疗组[雷尼替丁19.5mg/(kg·d),阿莫西林130mg/(kg·d),克拉霉素65mg/(kg·d)]及姜百胃炎片高剂量组[(3.12g/(kg·d)]、中剂量组[(1.56g/(kg·d)]和低剂量组[(0.78g/(kg·d)]。用细菌培养、pH指示剂法、尿素酶试验、抗体试验等评估实验小鼠Hp感染程度。统计方法采用秩和检验。结果 C57BL/6小鼠空白组、模型组、三联治疗组及姜百胃炎片高、中、低剂量组Hp感染程度尿素酶试验平均秩和(R-i,低优指标)分别为18.50、51.33、18.50、27.32、35.68和38.14,姜百胃炎片高剂量组Hp感染程度显著低于模型组(P<0.05);BALB/c小鼠空白组、模型组、三联治疗组及姜百胃炎片高、中、低剂量组的组的R-i分别为24.00、58.73、31.17、27.58、32.08和36.58,姜百胃炎片三个剂量组Hp感染程度均显著低于模型组(P<0.05)。结论姜百胃炎片对Hp感染C57BL/6和BALB/c小鼠模型有抑菌作用。%Objective To investigate the anti-helicobacter pylori (Hp) activity of Jiangbai Weiyan tablets on Hp-infected mouse model. Methods The experimental mice (C57BL/6 and BALB/c) were pretreated with NaHCO3 and antibiotics, and inoculated with Hp SS1 strain to establish Hp-infected mouse model. The Hp infected mice were randomly divided into model group, triple therapy group(ranitidine 19.5mg·kg-1·d-1, amoxicillin 130mg·kg-1·d-1, clarithromycin 65mg·kg-1·d-1), high-dose(3.12g·kg-1·d-1), mid-dose(1.56g·kg-1·d-1), and low-dose(0.78mg·kg-1·d-1) groups of Jiangbai Weiyan tablets. Bacterial culture, pH indicator diagnostic test, urease test, and antibody test were used to evaluate the

  19. Model Reduction of Hybrid Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    systems are derived in this thesis. The results are used for output feedback control of switched nonlinear systems. Model reduction of piecewise affine systems is also studied in this thesis. The proposed method is based on the reduction of linear subsystems inside the polytopes. The methods which......High-Technological solutions of today are characterized by complex dynamical models. A lot of these models have inherent hybrid/switching structure. Hybrid/switched systems are powerful models for distributed embedded systems design where discrete controls are applied to continuous processes...... of hybrid systems, designing controllers and implementations is very high so that the use of these models is limited in applications where the size of the state space is large. To cope with complexity, model reduction is a powerful technique. This thesis presents methods for model reduction and stability...

  20. Preparation and evaluation of diclofenac sodium orally disintegrating tablets

    Directory of Open Access Journals (Sweden)

    Iancu Valeriu

    2016-06-01

    Full Text Available Orally disintegrating tablets (ODTs are dosage forms which disintegrate in mouth within seconds without need of water. This type of quality in dosage form can be attained by addition of different varieties of excipients. Pharmaburst™ 500 is a co-processed excipient system which allows rapid disintegration and low adhesion to punches. The aim of the present study was to develop and evaluate 25 mg diclofenac sodium ODTs (orodispersible tablets batches by direct compression method at different compression forces 10 kN (F1 and 20 kN (F2 and directly compressible excipients used in different ratio (Avicel PH 102, magnesium stearate and coprocessed excipient Pharmaburst™ 500, 70% and 80% w/w. The obtained batches were analyzed for appearance, tablet thickness, uniformity of weight, hardness, friability, disintegration time, and non-compendial methods (wetting time. Co-processed Pharmaburst™ 500 excipient 70% used for sodium diclofenac ODT obtaining determined good results for quality control tests evaluation.

  1. Modelling on fuzzy control systems

    Institute of Scientific and Technical Information of China (English)

    LI; Hongxing(李洪兴); WANG; Jiayin(王加银); MIAO; Zhihong(苗志宏)

    2002-01-01

    A kind of modelling method for fuzzy control systems is first proposed here, which is calledmodelling method based on fuzzy inference (MMFI). It should be regarded as the third modelling method thatis different from two well-known modelling methods, that is, the first modelling method, mechanism modellingmethod (MMM), and the second modelling method, system identification modelling method (SlMM). Thismethod can, based on the interpolation mechanism on fuzzy logic system, transfer a group of fuzzy inferencerules describing a practice system into a kind of nonlinear differential equation with variable coefficients, calledHX equations, so that the mathematical model of the system can be obtained. This means that we solve thedifficult problem of how to get a model represented as differential equations on a complicated or fuzzy controlsystem.

  2. “Formulation and evaluation of starch acetate matrix tablets in combination with surfactants for controlled release”

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar Vishwanadha

    2015-04-01

    Full Text Available In the present study, an attempt has been made to evaluate starch acetate in combination with surfactant for the controlled release profile of drug from matrix system. Ibuprofen was used as a model drug to evaluate its release characteristics from different matrices. Starch acetate was synthesized, characterized and then employed in the matrix tablets as a hydrophobic polymer in different ratios in combination with SLS. Formulated tablets were characterized for parameters like thickness, weight variation, drug content uniformity, hardness, friability and in-vitro release rate profile and the release data were analysed as per various kinetic models. From the data it was found that the release was following first order kinetics for all the formulationsexcept F8 release profile of which followed zero order and the mechanism of release was found to be Non-fickian diffusion for all the formulations.

  3. Energy System Modeling with REopt

    Energy Technology Data Exchange (ETDEWEB)

    Simpkins, Travis; Anderson, Kate; Cutler, Dylan; Olis, Dan; Elgqvist, Emma; DiOrio, Nick; Walker, Andy

    2016-07-15

    This poster details how REopt - NREL's software modeling platform for energy systems integration and optimization - can help to model energy systems. Some benefits of modeling with REopt include optimizing behind the meter storage for cost and resiliency, optimizing lab testing, optimizing dispatch of utility scale storage, and quantifying renewable energy impact on outage survivability.

  4. Online medical symbol recognition using a Tablet PC

    Science.gov (United States)

    Kundu, Amlan; Hu, Qian; Boykin, Stanley; Clark, Cheryl; Fish, Randy; Jones, Stephen; Moore, Stephen

    2011-01-01

    In this paper we describe a scheme to enhance the usability of a Tablet PC's handwriting recognition system by including medical symbols that are not a part of the Tablet PC's symbol library. The goal of this work is to make handwriting recognition more useful for medical professionals accustomed to using medical symbols in medical records. To demonstrate that this new symbol recognition module is robust and expandable, we report results on both a medical symbol set and an expanded symbol test set which includes selected mathematical symbols.

  5. Huoxue Rongluo Tablet reduces matrix metalloproteinase-9 expression in infarcted brain tissue

    Institute of Scientific and Technical Information of China (English)

    Desheng Zhou; Mei Li; Hua Hu; Yao Chen; Yang Yang; Jie Zhong; Lijuan Liu

    2013-01-01

    Huoxue Rongluo Tablet was made of tal gastrodis tuber, dahurian angelica root, honeysuckle stem, grassleaf sweetflag rhizome, common flowering quince fruit, figwort root, red peony root and peach seed at a ratio of 3:2:6:2:3:3:3:3. Huoxue Rongluo Tablet is a wel-established and common pre-scription for the treatment of cerebral infarction. In this study, a rat model of cerebral ischemia was established and the animals were intragastrical y administered Huoxue Rongluo Tablet. This treat-ment reduced infarct volume, decreased matrix metal oproteinase-9 expression, and improved neurological function. Moreover, the effects of Huoxue Rongluo Tablet were better than those of buflomedil pyridoxal phosphate. These results indicate that Huoxue Rongluo Tablet is effective in treating cerebral infarction by regulating matrix metal oproteinase-9 protein expression.

  6. Development of mini-tablets with 1mm and 2mm diameter.

    Science.gov (United States)

    Tissen, Corinna; Woertz, Katharina; Breitkreutz, Joerg; Kleinebudde, Peter

    2011-09-15

    The feasibility of formulating mini-tablets with 1mm diameter on a rotary-die press in comparison to mini-tablets of 2mm was investigated. To gain insight into the production of 1mm mini-tablets, three model drugs of different compression characteristics were chosen, namely quinine hydrochloride, ibuprofen and spray-dried gentian extract. A high drug load in combination with robust and reproducible mechanical properties was requested. Depending on the individual drug substance, mini-tablets were produced by direct compression or after roll-compaction/dry granulation. The tensile strength, mass, and their variation coefficients were determined to assess the mechanical properties of the tablets. The content uniformity and the dissolution behavior of selected batches were analyzed. For the first time 1mm mini-tablets could be successfully produced by direct compression (90% quinine hydrochloride; 90% dried gentian extract) and after roll compaction (70% ibuprofen). Depending on the applied compression pressure, 1mm mini-tablets with quinine hydrochloride exhibited robust mechanical properties (e.g. median tensile strength of 2.02N/mm(2)) with equal or lower variance of distribution compared to the 2mm compacts. With respect to content uniformity of dosage forms, 1mm mini-tablets containing 80% quinine hydrochloride met the requirements of the European Pharmacopeia (AV=6.8).

  7. Evaluation of enteric-coated tablets as a whole cell inactivated vaccine candidate against Vibrio cholerae.

    Science.gov (United States)

    Fernández, Sonsire; Año, Gemma; Castaño, Jorge; Pino, Yadira; Uribarri, Evangelina; Riverón, Luis A; Cedré, Bárbara; Valmaseda, Tania; Falero, Gustavo; Pérez, José L; Infante, Juan F; García, Luis G; Solís, Rosa L; Sierra, Gustavo; Talavera, Arturo

    2013-01-01

    A vaccine candidate against cholera was developed in the form of oral tablets to avoid difficulties during application exhibited by current whole cell inactivated cholera vaccines. In this study, enteric-coated tablets were used to improve the protection of the active compound from gastric acidity. Tablets containing heat-killed whole cells of Vibrio cholerae strain C7258 as the active pharmaceutical compound was enteric-coated with the polymer Kollicoat(®) MAE-100P, which protected them efficiently from acidity when a disintegration test was carried out. Enzyme-linked immunosorbent assay (ELISA) anti-lipopolysaccharide (LPS) inhibition test and Western blot assay revealed the presence of V. cholerae antigens as LPS, mannose-sensitive haemagglutinin (MSHA) and outer membrane protein U (Omp U) in enteric-coated tablets. Immunogenicity studies (ELISA and vibriocidal test) carried out by intraduodenal administration in rabbits showed that the coating process of tablets did not affect the immunogenicity of V. cholerae-inactivated cells. In addition, no differences were observed in the immune response elicited by enteric-coated or uncoated tablets, particularly because the animal model and immunization route used did not allow discriminating between acid resistances of both tablets formulations in vivo. Clinical studies with volunteers will be required to elucidate this aspect, but the results suggest the possibility of using enteric-coated tablets as a final pharmaceutical product for a cholera vaccine.

  8. Digital Hammurabi: design and development of a 3D scanner for cuneiform tablets

    Science.gov (United States)

    Hahn, Daniel V.; Duncan, Donald D.; Baldwin, Kevin C.; Cohen, Jonathon D.; Purnomo, Budirijanto

    2006-02-01

    Cuneiform is an ancient form of writing in which wooden reeds were used to impress shapes upon moist clay tablets. Upon drying, the tablets preserved the written script with remarkable accuracy and durability. There are currently hundreds of thousands of cuneiform tablets spread throughout the world in both museums and private collections. The global scale of these artifacts presents several problems for scholars who wish to study them. It may be difficult or impossible to obtain access to a given collection. In addition, photographic records of the tablets many times prove to be inadequate for proper examination. Photographs lack the ability to alter the lighting conditions and view direction. As a solution to these problems, we describe a 3D scanner capable of acquiring the shape, color, and reflectance of a tablet as a complete 3D object. This data set could then be stored in an online library and manipulated by suitable rendering software that would allow a user to specify any view direction and lighting condition. The scanner utilizes a camera and telecentric lens to acquire images of the tablet under varying controlled illumination conditions. Image data are processed using photometric stereo and structured light techniques to determine the tablet shape; color information is reconstructed from primary color monochrome image data. The scanned surface is sampled at 26.8 μm lateral spacing and the height information is calculated on a much smaller scale. Scans of adjacent tablet sides are registered together to form a 3D surface model.

  9. Formulation And Characterization Of 5- Flourouracil Matrix Tablets Using Natural Polymers For Colon Specific Drug Delivery

    Directory of Open Access Journals (Sweden)

    Yaswanth Allamneni

    2012-03-01

    Full Text Available Purpose: The objective of the present investigation is to develop colon targeted drug delivery system by using combination of natural polymers as a carriers for 5-Flourouracil (5-FU. Site‐specific delivery of 5‐FU to the colon overcomes the side effects associated with the parenteral delivery of the drug, which include gastrointestinal toxicity, hematological and neural disorders and cardiac manifestations. Methods: Matrix tablets containing various proportions of Pectin and Xanthan gum were prepared by direct compression technique. Multilayer tablets were formulated using pectin as release controlling layers, on either side of 5- Flourouracil matrix tablets. The matrix tablets were evaluated by different In Process Quality Control tests, content uniformity and in vitro drug release study. Comparison of pectin multilayer tablets collected at the end of test performed in the presence or absence of pectinolytic enzymes made it possible to visibly appreciate theeffect of enzymatic activity on the the aspect of the residual matrix. Results and Conclusion: The FTIR spectra’s study revealed that there were no interaction between polymers and drug. The tablets passed all the pharmacopoeial tests. The matrix tablets containing various proportions of Pectin and xanthan gum failed to control drug release in the physiological environment of the stomach and small intestine. On the other hand, multilayer formulations were able to protect the tablet cores from premature drug release. The multilayer tabletsin the presence of pectinolytic enzymes, undergoes a faster erosion process which resulted in marked increase inthe drug release rate.

  10. Bilayer Tablet Formulation of Metformin HCl and Acarbose: A Novel Approach To Control Diabetes.

    Science.gov (United States)

    Tiwari, Ruchi; Gupta, Ankita; Joshi, Meenakshi; Tiwari, Gaurav

    2014-01-01

    The present investigation studied a novel bilayer tablet having an extended release system of metformin HCl with Eudragit RS 100 and RL 100 and an immediate release system of acarbose with polyvinylpyrrolidone K30 (PVP K30) and polyethylene glycol 6000 (PEG 6000) in different ratios using solvent evaporation and cogrinding techniques. Solid dispersions (SDs) were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), powder x-ray diffractometry (XRD), scanning electron microscopy (SEM), as well as by content uniformity, in vitro dissolution studies, and release kinetics. The selected SD system was subjected to bilayer tablet preparation by direct compression. Compressed tablets were evaluated for drug content, weight variation, friability, hardness, and thickness, and they underwent in vitro dissolution studies. The progressive disappearance of IR, x-ray, and thermotropic drug signals in SDs and physical mixtures were related to increasing amount of polymer. SEM studies suggested the homogenous dispersion of drug in polymers. FT-IR studies confirmed the formation of hydrogen bonding between drug and polymer. All tablet formulations showed compliance with pharmacopoeial standards. The formulations gave an initial burst effect to provide the loading dose of the drug followed by extended release for 12 h (Higuchi model via a non-Fickian diffusion controlled release mechanism). Stability studies conducted for the optimized formulation did not show any change in physical properties, drug content, or in vitro drug release. The goal of diabetes therapy today is to achieve and maintain as near normal glycemia as possible to prevent the long-term microvascular and macrovascular complications of elevated blood glucose levels. Oral therapeutic options for the treatment of type 2 diabetes mellitus, until recently, have been severely limited. Metformin, a biguanide, targets additional mechanisms of hyperglycemia by inhibiting

  11. Preparation and in vitro evaluation of guar gum based triple-layer matrix tablet of diclofenac sodium

    OpenAIRE

    Chavda, H. V.; M. S. Patel; Patel, C N

    2012-01-01

    The objective of the present study was to design an oral controlled drug delivery system for sparingly soluble diclofenac sodium (DCL) using guar gum as triple-layer matrix tablets. Matrix tablet granules containing 30% (D1), 40% (D2) or 50% (D3) of guar gum were prepared by the conventional wet granulation technique. Matrix tablets of diclofenac sodium were prepared by compressing three layers one by one. Centre layer of sandwich like structure was incorporated with matrix granules containin...

  12. [Splitting of tablets: small pieces a risk].

    Science.gov (United States)

    Picksak, Gesine; Stichtenoth, Dirk O

    2007-09-01

    For economic reasons physicians prescribe more and more multiunit tablets. Splitting of multiunit tablets depends on the physical-chemical properties of the agents, the galenic of the dosage form, the size and contour of the tablet and the shape of the score. Tablets with one or more scores are prepared to be divided for a single/multiple dose. How easily and exact a tablet can be divided depends heavily on the physical shape, its size and the outfit of the score. The fragments have to fulfil the requirements according to the European Pharmacopoeia: Uniformity of multiunit tablets. Since exact dosing is guaranteed only if tablets are divided properly, information and guidance of the patients by the physician and pharmacist is of critical importance.

  13. Raman spectroscopy for the analytical quality control of low-dose break-scored tablets.

    Science.gov (United States)

    Gómez, Diego A; Coello, Jordi; Maspoch, Santiago

    2016-05-30

    Quality control of solid dosage forms involves the analysis of end products according to well-defined criteria, including the assessment of the uniformity of dosage units (UDU). However, in the case of break-scored tablets, given that tablet splitting is widespread as a means to adjust doses, the uniform distribution of the active pharmaceutical ingredient (API) in all the possible fractions of the tablet must be assessed. A general procedure to accomplish with both issues, using Raman spectroscopy, is presented. It is based on the acquisition of a collection of spectra in different regions of the tablet, that later can be selected to determine the amount of API in the potential fractions that can result after splitting. The procedure has been applied to two commercial products, Sintrom 1 and Sintrom 4, with API (acenocoumarol) mass proportion of 2% and 0.7% respectively. Partial Least Squares (PLS) calibration models were constructed for the quantification of acenocoumarol in whole tablets using HPLC as a reference analytical method. Once validated, the calibration models were used to determine the API content in the different potential fragments of the scored Sintrom 4 tablets. Fragment mass measurements were also performed to estimate the range of masses of the halves and quarters that could result after tablet splitting. The results show that Raman spectroscopy can be an alternative analytical procedure to assess the uniformity of content, both in whole tablets as in its potential fragments, and that Sintrom 4 tablets can be perfectly split in halves, but some cautions have to be taken when considering the fragmentation in quarters. A practical alternative to the use of UDU test for the assessment of tablet fragments is proposed.

  14. Modeling soft interface dominated systems

    NARCIS (Netherlands)

    Lamorgese, A.; Mauri, R.; Sagis, L.M.C.

    2017-01-01

    The two main continuum frameworks used for modeling the dynamics of soft multiphase systems are the Gibbs dividing surface model, and the diffuse interface model. In the former the interface is modeled as a two dimensional surface, and excess properties such as a surface density, or surface energy

  15. Validation of systems biology models

    NARCIS (Netherlands)

    Hasdemir, D.

    2015-01-01

    The paradigm shift from qualitative to quantitative analysis of biological systems brought a substantial number of modeling approaches to the stage of molecular biology research. These include but certainly are not limited to nonlinear kinetic models, static network models and models obtained by the

  16. Modeling of deterministic chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Y. [Department of Physics and Astronomy and Department of Mathematics, The University of Kansas, Lawrence, Kansas 66045 (United States); Grebogi, C. [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States); Grebogi, C.; Kurths, J. [Department of Physics and Astrophysics, Universitaet Potsdam, Postfach 601553, D-14415 Potsdam (Germany)

    1999-03-01

    The success of deterministic modeling of a physical system relies on whether the solution of the model would approximate the dynamics of the actual system. When the system is chaotic, situations can arise where periodic orbits embedded in the chaotic set have distinct number of unstable directions and, as a consequence, no model of the system produces reasonably long trajectories that are realized by nature. We argue and present physical examples indicating that, in such a case, though the model is deterministic and low dimensional, statistical quantities can still be reliably computed. {copyright} {ital 1999} {ital The American Physical Society}

  17. Modelling of wastewater systems

    DEFF Research Database (Denmark)

    Bechmann, Henrik

    In this thesis, models of pollution fluxes in the inlet to 2 Danish wastewater treatment plants (WWTPs) as well as of suspended solids (SS) concentrations in the aeration tanks of an alternating WWTP and in the effluent from the aeration tanks are developed. The latter model is furthermore used...

  18. Novel Strategy to Fabricate Floating Drug Delivery System Based on Sublimation Technique.

    Science.gov (United States)

    Huanbutta, Kampanart; Limmatvapirat, Sontaya; Sungthongjeen, Srisagul; Sriamornsak, Pornsak

    2016-06-01

    The present study aims to develop floating drug delivery system by sublimation of ammonium carbonate (AMC). The core tablets contain a model drug, hydrochlorothiazide, and various levels (i.e., 0-50% w/w) of AMC. The tablets were then coated with different amounts of the polyacrylate polymers (i.e., Eudragit® RL100, Eudragit® RS100, and the mixture of Eudragit® RL100 and Eudragit® RS100 at 1:1 ratio). The coated tablets were kept at ambient temperature (25°C) or cured at 70°C for 12 h before further investigation. The floating and drug release behaviors of the tablets were performed in simulated gastric fluid USP without pepsin at 37°C. The results showed that high amount of AMC induced the floating of the tablets. The coated tablets containing 40 and 50% AMC floated longer than 8 h with a time-to-float of about 3 min. The sublimation of AMC from the core tablets decreased the density of system, causing floating of the tablets. The tablets coated with Eudragit® RL100 floated at a faster rate than those of Eudragit® RS100. Even the coating level of polymer did not influence the time-to-float and floating time of coated tablets containing the same amount of AMC, the drug release from the tablets coated with higher coating level of polymer showed slower drug release. The results suggested that the sublimation technique using AMC is promising for the development of floating drug delivery system.

  19. Modelling Epistemic Systems

    CERN Document Server

    Martins, Andre C R

    2012-01-01

    In this Chapter, I will explore the use of modeling in order to understand how Science works. I will discuss the modeling of scientific communities, providing a general, non-comprehensive overview of existing models, with a focus on the use of the tools of Agent-Based Modeling and Opinion Dynamics. A special attention will be paid to models inspired by a Bayesian formalism of Opinion Dynamics. The objective of this exploration is to better understand the effect that different conditions might have on the reliability of the opinions of a scientific community. We will see that, by using artificial worlds as exploring grounds, we can prevent some epistemological problems with the definition of truth and obtain insights on the conditions that might cause the quest for more reliable knowledge to fail.

  20. From Numeric Models to Granular System Modeling

    Directory of Open Access Journals (Sweden)

    Witold Pedrycz

    2015-03-01

    To make this study self-contained, we briefly recall the key concepts of granular computing and demonstrate how this conceptual framework and its algorithmic fundamentals give rise to granular models. We discuss several representative formal setups used in describing and processing information granules including fuzzy sets, rough sets, and interval calculus. Key architectures of models dwell upon relationships among information granules. We demonstrate how information granularity and its optimization can be regarded as an important design asset to be exploited in system modeling and giving rise to granular models. With this regard, an important category of rule-based models along with their granular enrichments is studied in detail.

  1. Developing a Lecturer Workshop for Using Tablets in the Classroom

    Science.gov (United States)

    Louw, Arno

    2015-01-01

    This paper is about a framework as heuristic to design and develop a workshop for academic teaching staff to use tablets for teaching and learning in the classroom at the University of Johannesburg (UJ). Theories of Cultural-Historical Activity and Engeström's activity systems are also incorporated, as are a critique and a critical analysis of the…

  2. Pluralistic Modeling of Complex Systems

    CERN Document Server

    Helbing, Dirk

    2010-01-01

    The modeling of complex systems such as ecological or socio-economic systems can be very challenging. Although various modeling approaches exist, they are generally not compatible and mutually consistent, and empirical data often do not allow one to decide what model is the right one, the best one, or most appropriate one. Moreover, as the recent financial and economic crisis shows, relying on a single, idealized model can be very costly. This contribution tries to shed new light on problems that arise when complex systems are modeled. While the arguments can be transferred to many different systems, the related scientific challenges are illustrated for social, economic, and traffic systems. The contribution discusses issues that are sometimes overlooked and tries to overcome some frequent misunderstandings and controversies of the past. At the same time, it is highlighted how some long-standing scientific puzzles may be solved by considering non-linear models of heterogeneous agents with spatio-temporal inte...

  3. 茴拉西坦自乳化给药系统与片剂的药代动力学及体内外相关性的研究%Pharmacokinetics and in vitro-in vivo correlation evaluation of self-emulsifying drug delivery system and conventional tablets of aniracetam

    Institute of Scientific and Technical Information of China (English)

    李娟; 张燕; 王广基

    2007-01-01

    目的:研究茴拉西坦自乳化制剂和普通片剂的体内外相关关系;评价其大鼠口服给药的体内药代动力学.方法:通过测定自乳化制剂和普通片剂的体外溶出度考察其释药特性,采用RP-HPLC法测定活性代谢产物对氨基甲氧基丁酸的浓度血浆中,通过Wagner-Nelson法计算体内吸收分数(f),研究两制剂的吸收分数(f)与体外累积溶出度(Q%)的相关性.结果:自乳化微乳体外 15 min 的溶出度为(80±4)%,比片剂的溶出度(50%)明显提高;体内代谢产物的回收率为90%,日内日间精密度分别小于4%和6%,该方法灵敏度高、准确可靠.自乳化微乳的AUC0-∞为(11 168±2 395)ng·mL-1·h,是普通片剂的3倍.自乳化微乳和片剂的MRT0-∞分别为(2.7±0.6) h和(1.7±0.5) h,具有统计学差异(P<0.05).体内外相关性结果表明,片剂的体内吸收与体外溶出度呈线性相关,线性方程的斜率为 0.7765,截距为-2.9527;自乳化微乳的体内外相关性符合二次模型,其拟合系数为 0.972.结论:茴拉西坦自乳化给药系统可显著提高药物体内的生物利用度.自乳化制剂处方中含有促吸收的复合表面活性剂和油相,其体外药物呈快速释放的特性,而体内自发与胃肠液形成o/w型微乳后可通过淋巴转运的吸收途径.%AIM: To evaluate the correlation between in vitro release and in vivo absorption of aniracetam in conventional tablets and self-emulsifying drug delivery system (SEDDS), to investigate pharmacokinetics of aniracetam self-emulsifying drug delivery system and conventional tablets of aniracetam after oral administration to rats. METHODS: Dissolution behavior of these formulations was evaluated in vitro to assess the properties of dosage forms. And a new RP-HPLC method was developed for the in vivo quantitative determination of 4-p-anisamidobutyric acid (PABA), the active metabolite of aniracetam. To approach the in vitro-in vivo correlation, fraction absorbed in vivo (f

  4. 硝苯地平缓释片体内外相关性模型的建立与评估%Develop and Evaluate the in vitro-in vivo Correlation Model of Nifedipine Extendedrelease Tablets

    Institute of Scientific and Technical Information of China (English)

    袁春平; 陆启春; 游伟良; 任秀华; 杜光

    2012-01-01

    Objective To develop and evaluate the in vitro-in vivo correlation model (IVIVC) of nifedipine extended-release tablets. Methods A release condition that distinguished different formulations was screened and the accumulated release rate (Fd) of nifedipine extended-release tablets was determined by HPIX. The plasma drug level of healthy volunteers after single oral dose of nifedipine extended-release tablets with different release rates were determined by LC-MS/MS. The accumulated absorption percentage (fa) was calculated by the equation of Wagner-Nelson. Results Our study showed that good correlation appeared between in vitro release and in vivo absorption of the two formulations. The formulation which was bioequivalent to Adalat GITS was used to create a IVIVC model: Fa = 0. 831 4 Fd+0. 005 2, r = 0. 980 8, P = 0.0006 (P< 0.01). Another formulation was used to estimate the prediction error externally of the model, and the prediction error was: PE% (AUC0-24)=3.2%, PE%(Cmax)=3.5%. Conclusion The 1VIVC model can well forecast the characteristics of the in vivo absorption of nifedipine extended-release tablets effectively, which provides the basis for making product quality standards.%目的 建立和评价硝苯地平缓释片体内外相关性(IVIVC)的模型.方法 筛选不同处方片剂的体外释放条件,采用高效液相色谱(HPLC)法测定其累积释放百分率(Fd);液相色谱串联-质谱(LC-MS/MS)法测定健康志愿者单剂量口服两种不同释放速率的硝苯地平缓释片后的血药浓度,利用Wagner-Nelson方程计算累积吸收百分率(Fa).结果 两种制剂体外释放与体内累积吸收相关性均良好,用与硝苯地平控释片生物等效的制剂,创建IVIVC模型:Fa=0.831 4 Fd+0.005 2,r=0.980 8(P<0.01);用另一种制剂对其模型进行外部预测能力的评估:AUC0-24和Cmax的预测误差分别为3.2%,3.5%.结论 IVIVC模型具有良好的预测硝苯地平缓释片体内吸收的能力,为硝苯地平缓

  5. Construction of a Quantitative Model for Determination of Indometacin Enteric-Coated Tablets%吲哚美辛肠溶片近红外快速定量方法的建立

    Institute of Scientific and Technical Information of China (English)

    吴群

    2016-01-01

    Objective To quantitatively analyze the Indometacin Enteric-coated Tablets by near infrared diffuse reflection spectroscopy technology and chemometrics. Methods 156 batches of Indometacin Enteric-coated Tablets from 8 different manufacturers were chosen for analyzing. The near infrared diffuse reflection spectrum of the samples was collected;the active pharmaceutical ingredient(API)con-tents were determined by the conventional method;the model with the partial least square(PLS) algorithm available in the quant was developed. Results The model was based on cross validation with API from 24. 61% to 32. 96%. 78 batches were used as validation set,the RMSEP was 0. 508%,and the average relative deviation for the validation set was 0. 45%. Conclusion The method is accu-rate,quick and convenient,which can be used for quick analysis in drug control.%目的:采用近红外漫反射光谱(NIR)分析技术和化学计量学方法对吲哚美辛肠溶片进行快速定量分析。方法选择8个厂家生产的156批吲哚美辛肠溶片,采集样品的NIR,并以法定方法测定其含量,采用偏最小二乘法建立定量模型。结果样品浓度范围为24.61%~32.96%,用78个样品进行外部验证,外部验证均方差(RMSEP)为0.508%,平均相对偏差为0.45%。结论该方法快速、简便,结果准确,适于药品的现场快检。

  6. Integrated Modeling Systems

    Science.gov (United States)

    1989-01-01

    American Economic Review , 71:1 (March 1981). 181 J.M. Jones and F. Zufryden. "Adding Explanatory Variables to a Consumer Purchase Behavior Model: An...McCall. "An Operational Measure of Liquidity," The American Economic Review , 761 (March 1986). WMSI Working Paper 329. 212 Nelson, R., R. Sarin, and R

  7. Robust Disaster Recovery System Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Highly security-critical system should possess features of continuous service. We present a new Robust Disaster Recovery System Model (RDRSM). Through strengthening the ability of safe communications, RDRSM guarantees the secure and reliable command on disaster recovery. Its self-supervision capability can monitor the integrality and security of disaster recovery system itself. By 2D and 3D real-time visible platform provided by GIS, GPS and RS, the model makes the using, management and maintenance of disaster recovery system easier. RDRSM possesses predominant features of security, robustness and controllability. And it can be applied to highly security-critical environments such as E-government and bank. Conducted by RDRSM, an important E-government disaster recovery system has been constructed successfully. The feasibility of this model is verified by practice. We especially emphasize the significance of some components of the model, such as risk assessment, disaster recovery planning, system supervision and robust communication support.

  8. Integrated evaluation of HPLC and UV fingerprints for the quality control of Danshen tablet by systematic quantified fingerprint method combined with antioxidant activity.

    Science.gov (United States)

    Shi, Min; Sun, Guoxiang

    2017-03-20

    Danshen tablet, which consists of Salviae Miltiorrhizae Radix et Rhizoma, Notoginseng Radix et Rhizoma and Borneolum syntheticum, has been widely used in the therapy of cardiovascular disease. The aim of this study was to develop comprehensive evaluation methods for the quality control of Danshen tablet. First, five-wavelength fusion fingerprint was established to avoid one-sidedness of a single wavelength. Then, the ultraviolet spectrum fingerprint was applied to reflect the information of unsaturated bond and conjugated system of chemical substances in Danshen tablet. The similarity analyses of these two fingerprints were performed by systematic quantified fingerprint method in terms of qualitative and quantitative aspects. After that, the evaluation results of high-performance liquid chromatography and ultraviolet fingerprints were integrated by the mean algorithm, which could reduce the error caused by single method. The integrated evaluation results showed that 30 batches of samples were classified into seven grades. Finally, the fingerprint-efficacy relationship was established using an on-line antioxidant system and partial least squares model to explore the connection between chemical components and antioxidant activities. The methods established in this paper had proven to be suitable for the analysis of Danshen tablet. This article is protected by copyright. All rights reserved.

  9. Mechanical Systems, Classical Models

    CERN Document Server

    Teodorescu, Petre P

    2007-01-01

    All phenomena in nature are characterized by motion; this is an essential property of matter, having infinitely many aspects. Motion can be mechanical, physical, chemical or biological, leading to various sciences of nature, mechanics being one of them. Mechanics deals with the objective laws of mechanical motion of bodies, the simplest form of motion. In the study of a science of nature mathematics plays an important role. Mechanics is the first science of nature which was expressed in terms of mathematics by considering various mathematical models, associated to phenomena of the surrounding nature. Thus, its development was influenced by the use of a strong mathematical tool; on the other hand, we must observe that mechanics also influenced the introduction and the development of many mathematical notions. In this respect, the guideline of the present book is precisely the mathematical model of mechanics. A special accent is put on the solving methodology as well as on the mathematical tools used; vectors, ...

  10. Microporous bilayer osmotic tablet for colon-specific delivery.

    Science.gov (United States)

    Chaudhary, Anil; Tiwari, Neha; Jain, Vikas; Singh, Ranjit

    2011-05-01

    Microporous bilayer osmotic tablet bearing dicyclomine hydrochloride and diclofenac potassium was developed using a new oral drug delivery system for colon targeting. The tablets were coated with microporous semipermeable membrane and enteric polymer using conventional pan-coating process. The developed microporous bilayer osmotic pump tablet (OPT) did not require laser drilling to form the drug delivery orifice. The colon-specific biodegradation of pectin could form in situ delivery pores for drug release. The effect of formulation variables like inclusion of osmogen, amount of HPMC and NaCMC in core, amount of pore former in semipermeable membrane was studied. Scanning electron microscopic photographs showed formation of in situ delivery pores after predetermined time of coming in contact with dissolution medium. The number of pores was dependent on the amount of the pore former in the semipermeable membrane. In vitro dissolution results indicated that system showed acid-resistant, timed release and was able to deliver drug at an approximate zero order up to 24h. The developed tablets could be effectively used for colon-specific drug delivery to treat IBS. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Preparation of coated valproic acid and sodium valproate sustained-release matrix tablets

    Directory of Open Access Journals (Sweden)

    Phaechamud T

    2010-01-01

    Full Text Available The aim of this research was to investigate the technique for preparation of coated valproic acid and sodium valproate sustained-release matrix tablets. Different diluents were tested and selected as the effective absorbent for oily valproic acid. Effect of the amount of absorbent and hydroxypropylmethylcellulose on drug release from valproic acid-sodium valproate matrix tablets prepared with wet granulation technique was evaluated in pH change system. Colloidal silicon dioxide effectively adsorbed liquid valproic acid during wet granulation and granule preparation. The amounts of colloidal silicon dioxide and hydroxypropylmethylcellulose employed in tablet formulations affected drug release from the tablets. The drug release was prominently sustained for over 12 h using hydroxypropylmethylcellulose-based hydrophilic matrix system. The mechanism of drug release through the matrix polymer was a diffusion control. The drug release profile of the developed matrix tablet was similar to Depakine Chrono; , providing the values of similarity factor (f2 and difference factor (f1 of 85.56 and 2.37, respectively. Eudragit; L 30 D-55 was used as effective subcoating material for core matrix tablets before over coating with hydroxypropylmethylcellulose film with organic base solvent. Drug release profile of coated matrix tablet was almost similar to that of Depakine Chrono; .

  12. Studies of Catalytic Model Systems

    DEFF Research Database (Denmark)

    Holse, Christian

    The overall topic of this thesis is within the field of catalysis, were model systems of different complexity have been studied utilizing a multipurpose Ultra High Vacuum chamber (UHV). The thesis falls in two different parts. First a simple model system in the form of a ruthenium single crystal...... is investigated. Second the development of a complex Cu/ZnO nanoparticle model system is described and gas-induced dynamical changes in the model system is investigated. The ruthenium crystal serves as an extremely simple model for studying CO dissociation which is the rate limiting step of the methanation...... process. The Ru(0 1 54) surface is studied by means of Scanning Tunneling Microscopy (STM), Temperature Programmed Desoprtion (TPD), and Oxygen Titration (OT) experiments. Real space evidence of periodic features on every second monatomic step is observed via STM when the a clean ruthenium surface...

  13. Relocatable Coastal Modeling System

    Science.gov (United States)

    2016-06-07

    These relationships are stored on a variable-resolution grid (illustrated in figure 1b below) with sampling of 1 degree in deep water (and in data...version is referred to as MODAS2.1, which is now operational at NAVO. The NOMADS interface is being replaced by a system-independent, web -based version...inside the user’s web browser plus Perl CGI scripts which ran on a webserver. This permitted the user to run MODAS (and POM and other modules as they are

  14. Assessment of active pharmaceutical ingredient particle size in tablets by Raman chemical imaging validated using polystyrene microsphere size standards.

    Science.gov (United States)

    Kuriyama, Atsushi; Ozaki, Yukihiro

    2014-04-01

    Particle size is a critical parameter for controlling pharmaceutical quality. The aim of this study was to assess the size of the micrometer-scale active pharmaceutical ingredients (API) in tablets using Raman chemical imaging and to understand the effects of formulation on particle size. Model tablets containing National Institute of Standards and Technology traceable polystyrene microsphere size standards were developed to determine the binarization threshold value of Raman chemical images for API particle sizing in specific formulations and processes. Three sets of model tablets containing 5, 10, and 15 μm polystyrene microspheres, used to mimic API, were prepared using a commercial tablet formulation (Ebastel tablets, mean API particle size was about 5 μm). Raman mapping with a 50× objective (NA, 0.75) was applied to tablet cross-sections, and particle size of polystyrene microspheres was estimated from binary images using several binarization thresholds. Mean particle size for three sets of polystyrene microspheres showed good agreement between pre- and postformulation (the slope = 1.024, R = 1.000) at the specific threshold value ((mean + 0.5σ) of the polystyrene-specific peak intensity histogram), regardless of particle agglomeration, tablet surface roughness, and laser penetration depth. The binarization threshold value showed good applicability to Ebastel tablets, where the API-specific peak intensity histogram showed a pattern similar to that of polystyrene microspheres in model tablets. The model tablets enabled determination of an appropriate binarization threshold for assessing the mean particle size of micrometer-scale API in tablets by utilizing the unique physicochemical properties of polystyrene microspheres.

  15. A better dissolution method for ranitidine tablets USP.

    Science.gov (United States)

    Cappola, M L

    2001-01-01

    Ranitidine tablets USP showed variable intra- and inter-lab dissolution results. In order to ascertain the reason for this behavior, ranitidine tablets USP produced by (BIPI) Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, and Zantac Tablets (brand of ranitidine USP), Glaxo Inc., Research Triangle, NC, were subjected to the compendia (USP) dissolution testing using paddle and basket apparatus. Two potencies of tablets 150 mg and 300 mg were tested. Comparison of BIPI tablets and matching Zantac tablets indicated that both brands of ranitidine tablets USP had similar dissolution behavior. When the basket apparatus was substituted for the paddle apparatus the overall rate and extent of tablet dissolution increased, while the individual tablet variability decreased. BIPI 150 mg tablets using the basket apparatus, but at reduced rotational speed of 30 rpm, showed increase in rate and extent of drug dissolved, with less individual tablet variability compared to the paddle apparatus at 50 rpm. The 300 mg tablet (30 rpm/basket apparatus) had an initial slower rate, but then rapidly equaled the paddle apparatus dissolution results, and had less individual tablet variability. Paddle apparatus tablet sinkers were used to prevent tablets from sticking to the bottom of the dissolution vessel. Overall dissolution for all tablets with sinkers showed a trend which was more rapid and complete than tablets without sinkers. Results showed that dissolution artifacts for ranitidine tablets could be reduced by the use of baskets or tablet sinkers.

  16. 辛伐他汀-β-环糊精包合物片对高脂血症模型大鼠血液流变学的影响%Effects of Simvastatin-β-cyclodextrin Inclusion Compound Tablets on Hemorheology in Model Rats with Hyperlipoidemia Disease

    Institute of Scientific and Technical Information of China (English)

    杨宗发; 何静; 韦丽佳; 江尚飞; 许燕

    2011-01-01

    目的:考察自制的辛伐他汀-β-环糊精包合物片(简称自制片)对高脂血症模型大鼠血液流变学的影响.方法:随机将60只大鼠中的10只设为空白组(蒸馏水),另50只高脂饲料喂养4周建立高脂血症大鼠模型,造模成功后随机分为5组:模型组(蒸馏水)、辛伐他汀片组(5.0 mg· kg-1· d-1)和自制片高、中、低(10.0、5.0、1.0 mg· kg-1·d-1)剂量组,每组10只,灌服给予相应药物,连续给药4周后,检测各组大鼠给药前、后全血黏度、红细胞沉降率(简称血沉)、红细胞压积以及血浆黏度等血液流变学参数的变化.结果:与模型组比较,辛伐他汀片组和自制片各剂量组大鼠的全血黏度、血沉、血浆黏度均明显降低(P<0.05),但辛伐他汀片组与自制片组比较无显著性差异;6组大鼠红细胞压积比较无显著性差异.结论:自制片可改善高脂血症模型大鼠的血液流变学特性,与辛伐他汀片作用相似.%OBJECTIVE: To investigate the effect of homemade Simvastatin-β-cyclodextrin inclusion compound tablets (self-made tablets) on hemorheology in model rats with hyperlipoidemia disease. METHODS: A total of 60 rats were included in study. 10 rats were included in blank group (distilled water). Other 50 rats were given high-fat diet for 4 weeks to induce hyperlipoidemia model then divided into 5 groups: model group (distilled water) , Simvastatin tablet group (5.0 mg·kg-1·d-1) and high-dose, medium-dose and low-dose self-made tablets groups (10.0, 5.0,1.0 mg·kg-1·d-1) with each group of 10 rats. 5 groups were given relevant medicine for 4 weeks. Changes of hemorheological parameters, including the whole blood viscosity, erythro-cyte sedimentation rate, hematocrit and plasma viscosity, were determined and analyzed before and after treatment. RESULTS: Compared with model group, the whole blood viscosity, blood sedimentation and plasma viscosity of Simvastatin tablet group and self-made tablets groups

  17. Can Tablet Computers Enhance Faculty Teaching?

    Science.gov (United States)

    Narayan, Aditee P; Whicker, Shari A; Benjamin, Robert W; Hawley, Jeffrey; McGann, Kathleen A

    2015-06-01

    Learner benefits of tablet computer use have been demonstrated, yet there is little evidence regarding faculty tablet use for teaching. Our study sought to determine if supplying faculty with tablet computers and peer mentoring provided benefits to learners and faculty beyond that of non-tablet-based teaching modalities. We provided faculty with tablet computers and three 2-hour peer-mentoring workshops on tablet-based teaching. Faculty used tablets to teach, in addition to their current, non-tablet-based methods. Presurveys, postsurveys, and monthly faculty surveys assessed feasibility, utilization, and comparisons to current modalities. Learner surveys assessed perceived effectiveness and comparisons to current modalities. All feedback received from open-ended questions was reviewed by the authors and organized into categories. Of 15 eligible faculty, 14 participated. Each participant attended at least 2 of the 3 workshops, with 10 to 12 participants at each workshop. All participants found the workshops useful, and reported that the new tablet-based teaching modality added value beyond that of current teaching methods. Respondents developed the following tablet-based outputs: presentations, photo galleries, evaluation tools, and online modules. Of the outputs, 60% were used in the ambulatory clinics, 33% in intensive care unit bedside teaching rounds, and 7% in inpatient medical unit bedside teaching rounds. Learners reported that common benefits of tablet computers were: improved access/convenience (41%), improved interactive learning (38%), and improved bedside teaching and patient care (13%). A common barrier faculty identified was inconsistent wireless access (14%), while no barriers were identified by the majority of learners. Providing faculty with tablet computers and having peer-mentoring workshops to discuss their use was feasible and added value.

  18. Variable efficacy of calcium carbonate tablets.

    Science.gov (United States)

    Kobrin, S M; Goldstein, S J; Shangraw, R F; Raja, R M

    1989-12-01

    Orally administered calcium carbonate tablets are commonly prescribed as a calcium supplement and for their phosphate-binding effects in renal failure patients. Two cases are reported in which a commercially available brand of calcium carbonate tablets appeared to be ineffective. Formal investigation of the bioavailability of this product revealed it to have impaired disintegration and dissolution and a lack of clinical efficacy. Recommendations that will enable physicians to avoid prescribing and pharmacists to avoid dispensing ineffective calcium carbonate tablets are proposed.

  19. Hydronic distribution system computer model

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Strasser, J.J.

    1994-10-01

    A computer model of a hot-water boiler and its associated hydronic thermal distribution loop has been developed at Brookhaven National Laboratory (BNL). It is intended to be incorporated as a submodel in a comprehensive model of residential-scale thermal distribution systems developed at Lawrence Berkeley. This will give the combined model the capability of modeling forced-air and hydronic distribution systems in the same house using the same supporting software. This report describes the development of the BNL hydronics model, initial results and internal consistency checks, and its intended relationship to the LBL model. A method of interacting with the LBL model that does not require physical integration of the two codes is described. This will provide capability now, with reduced up-front cost, as long as the number of runs required is not large.

  20. Data management system performance modeling

    Science.gov (United States)

    Kiser, Larry M.

    1993-01-01

    This paper discusses analytical techniques that have been used to gain a better understanding of the Space Station Freedom's (SSF's) Data Management System (DMS). The DMS is a complex, distributed, real-time computer system that has been redesigned numerous times. The implications of these redesigns have not been fully analyzed. This paper discusses the advantages and disadvantages for static analytical techniques such as Rate Monotonic Analysis (RMA) and also provides a rationale for dynamic modeling. Factors such as system architecture, processor utilization, bus architecture, queuing, etc. are well suited for analysis with a dynamic model. The significance of performance measures for a real-time system are discussed.

  1. TABLET COATING TECHNIQUES: CONCEPTS AND RECENT TRENDS

    OpenAIRE

    Gupta Ankit; Bilandi Ajay; Kataria Mahesh Kumar; Khatri Neetu

    2012-01-01

    Tablet coating is a common pharmaceutical technique of applying a thin polymer-based film to a tablet or a granule containing active pharmaceutical ingredients (APIs). Solid dosage forms are coated for a number of reasons, the most important of which is controlling the release profiles. The amount of coating on the surface of a tablet is critical to the effectiveness of the oral dosage form. Tablets are usually coated in horizontal rotating pans with the coating solution sprayed onto the free ...

  2. VALIDATION OF FILM COATED MULTIVITAMIN TABLETS

    Directory of Open Access Journals (Sweden)

    Vipin Kumar

    2013-06-01

    Full Text Available The validation is fundamental segment that supports to a commitment of company towards quality assurance. It also assures that product meets its predetermined quality specification and quality. Validation of each steps of manufacturing during multivitamin tablet formulation is called process validation of multivitamin tablets. During past film coating is not much favorable but now for multivitamin tablets film coating is used. The objective is to present a review and to discuss aspects of validation of film coated multivitamin tablets in terms of unit operations; that is, those individual technical operations that comprise the various steps involved in product design and evaluation.

  3. Evaluation of quick disintegrating calcium carbonate tablets.

    Science.gov (United States)

    Fausett, H; Gayser, C; Dash, A K

    2000-07-02

    The purpose of this investigation was to develop a rapidly disintegrating calcium carbonate (CC) tablet by direct compression and compare it with commercially available calcium tablets. CC tablets were formulated on a Carver press using 3 different forms of CC direct compressed granules (Cal-Carb 4450, Cal-Carb 4457, and Cal-Carb 4462). The breaking strength was measured using a Stokes-Monsanto hardness tester. The disintegration and dissolution properties of the tablets were studied using USP methodology. The calcium concentration was determined by an atomic absorption spectrophotometer. Scanning electron microscopy was used to evaluate the surface topography of the granules and tablets. Breaking strength of Cal-Carb 4450, Cal-Carb 4457, and Cal-Carb 4462 tablets was in the range of 7.2 to 7.7 kg, as compared with a hardness of 6.2 kg and 10 kg for the commercially available calcium tablets Citracal and Tums, respectively. The disintegration time for the tablets presented in the order earlier was 4.1, 2.1, 1.9, 2.9, and 9.7 minutes, respectively. The dissolution studies showed that all formulations released 100% of the elemental calcium in simulated gastric fluid in less than 20 minutes. In summary, this study clearly demonstrated that quick disintegrating CC tablets can be formulated without expensive effervescence technology.

  4. Modulation of venlafaxine hydrochloride release from press coated matrix tablet

    Directory of Open Access Journals (Sweden)

    Gohel M

    2008-01-01

    Full Text Available The aim of present study was to prepare novel modified release press coated tablets of venlafaxine hydrochloride. Hydroxypropylmethylcellulose K4M and hydroxypropylmethylcellulose K100M were used as release modifier in core and coat, respectively. A 3 2 full factorial design was adopted in the optimization study. The drug to polymer ratio in core and coat were chosen as independent variables. The drug release in the first hour and drug release rate between 1 and 12 h were chosen as dependent variables. The tablets were characterized for dimension analysis, crushing strength, friability and in vitro drug release. A check point batch, containing 1:2.6 and 1:5.4 drug to polymer in core and coat respectively, was prepared. The tablets of check point batch were subjected to in vitro drug release in dissolution media with pH 5, 7.2 and distilled water. The kinetics of drug release was best explained by Korsmeyer and Peppas model (anomalous non-Fickian diffusion. The systematic formulation approach enabled us to develop modified release venlafaxine hydrochloride tablets.

  5. Modulation of venlafaxine hydrochloride release from press coated matrix tablet.

    Science.gov (United States)

    Gohel, M C; Soni, C D; Nagori, S A; Sarvaiya, K G

    2008-01-01

    The aim of present study was to prepare novel modified release press coated tablets of venlafaxine hydrochloride. Hydroxypropylmethylcellulose K4M and hydroxypropylmethylcellulose K100M were used as release modifier in core and coat, respectively. A 3(2) full factorial design was adopted in the optimization study. The drug to polymer ratio in core and coat were chosen as independent variables. The drug release in the first hour and drug release rate between 1 and 12 h were chosen as dependent variables. The tablets were characterized for dimension analysis, crushing strength, friability and in vitro drug release. A check point batch, containing 1:2.6 and 1:5.4 drug to polymer in core and coat respectively, was prepared. The tablets of check point batch were subjected to in vitro drug release in dissolution media with pH 5, 7.2 and distilled water. The kinetics of drug release was best explained by Korsmeyer and Peppas model (anomalous non-Fickian diffusion). The systematic formulation approach enabled us to develop modified release venlafaxine hydrochloride tablets.

  6. Preparation and evaluation of gastroretentive floating tablets of Silymarin.

    Science.gov (United States)

    Garg, Rajeev; Gupta, Ghanshyam Das

    2009-06-01

    The present study performed by preparation and evaluation of floating tablets of Silymarin as model drug for prolongation of gastric residence time. Floating effervescent tablets were formulated by various materials like hydroxypropyl methylcellulose (HPMC) K 4M, K 15M, psyllium husk, swelling agent as crospovidone and microcrystalline cellulose and gas generating agent like sodium bicarbonate and citric acid and evaluated for floating properties, swelling characteristics and in vitro drug release studies. Floating noneffervescent tablets were prepared by polypropylene foam powder and different matrix forming polymers like HPMC K 4M, Carbopol 934P, xanthan gum and sodium alginate. In vitro drug release studies were performed and drug release kinetics evaluated using the linear regression method was found to follow both the Higuchi and the Korsemeyer and Peppas equation. The drug release mechanism was found fickian type in most of the formulations. The developed floating tablets of Silymarin may be used in clinic for prolonged drug release for at least 24 h, thereby improving the bioavailability and patient compliance.

  7. Rapid Assessment of Tablet Film Coating Quality by Multispectral UV Imaging.

    Science.gov (United States)

    Klukkert, Marten; Wu, Jian X; Rantanen, Jukka; Rehder, Soenke; Carstensen, Jens M; Rades, Thomas; Leopold, Claudia S

    2016-08-01

    Chemical imaging techniques are beneficial for control of tablet coating layer quality as they provide spectral and spatial information and allow characterization of various types of coating defects. The purpose of this study was to assess the applicability of multispectral UV imaging for assessment of the coating layer quality of tablets. UV images were used to detect, characterize, and localize coating layer defects such as chipped parts, inhomogeneities, and cracks, as well as to evaluate the coating surface texture. Acetylsalicylic acid tablets were prepared on a rotary tablet press and coated with a polyvinyl alcohol-polyethylene glycol graft copolymer using a pan coater. It was demonstrated that the coating intactness can be assessed accurately and fast by UV imaging. The different types of coating defects could be differentiated and localized based on multivariate image analysis and Soft Independent Modeling by Class Analogy applied to the UV images. Tablets with inhomogeneous texture of the coating could be identified and distinguished from those with a homogeneous surface texture. Consequently, UV imaging was shown to be well-suited for monitoring of the tablet coating layer quality. UV imaging is a promising technique for fast quality control of the tablet coating because of the high data acquisition speed and its nondestructive analytical nature.

  8. Formulation design and optimization of mouth dissolve tablets of nimesulide using vacuum drying technique.

    Science.gov (United States)

    Gohel, Mukesh; Patel, Madhabhai; Amin, Avani; Agrawal, Ruchi; Dave, Rikita; Bariya, Nehal

    2004-04-26

    The purpose of this research was to develop mouth dissolve tablets of nimesulide. Granules containing nimesulide, camphor, crospovidone, and lactose were prepared by wet granulation technique. Camphor was sublimed from the dried granules by exposure to vacuum. The porous granules were then compressed. Alternatively, tablets were first prepared and later exposed to vacuum. The tablets were evaluated for percentage friability, wetting time, and disintegration time. In the investigation, a 32 full factorial design was used to investigate the joint influence of 2 formulation variables: amount of camphor and crospovidone. The results of multiple linear regression analysis revealed that for obtaining a rapidly disintegrating dosage form, tablets should be prepared using an optimum concentration of camphor and a higher percentage of crospovidone. A contour plot is also presented to graphically represent the effect of the independent variables on the disintegration time and percentage friability. A checkpoint batch was also prepared to prove the validity of the evolved mathematical model. Sublimation of camphor from tablets resulted in superior tablets as compared with the tablets prepared from granules that were exposed to vacuum. The systematic formulation approach helped in understanding the effect of formulation processing variables.

  9. Formulation, Characterization and Physicochemical Evaluation of Ranitidine Effervescent Tablets

    Directory of Open Access Journals (Sweden)

    Abolfazl Aslani

    2013-08-01

    Full Text Available Purpose: The aim of this study was to design, formulate and physicochemically evaluate effervescent ranitidine hydrochloride (HCl tablets since they are easily administered while the elderly and children sometimes have difficulties in swallowing oral dosage forms. Methods: Effervescent ranitidine HCl tablets were prepared in a dosage of 300 mg by fusion and direct compression methods. The powder blend and granule mixture were evaluated for various pre-compression characteristics, such as angle of repose, compressibility index, mean particle size and Hausner's ratio. The tablets were evaluated for post-compression features including weight variation, hardness, friability, drug content, dissolution time, carbon dioxide content, effervescence time, pH, content uniformity and water content. Effervescent systems with appropriate pre and post-compression qualities dissolved rapidly in water were selected as the best formulations. Results: The results showed that the flowability of fusion method is more than that of direct compression and the F5 and F6 formulations of 300 mg tablets were selected as the best formulations because of their physicochemical characteristics. Conclusion: In this study, citric acid, sodium bicarbonate and sweeteners (including mannitol, sucrose and aspartame were selected. Aspartame, mint and orange flavors were more effective for masking the bitter taste of ranitidine. The fusion method is the best alternative in terms of physicochemical and physical properties.

  10. Formulation and evaluation of sublingual tablets of losartan potassium

    Directory of Open Access Journals (Sweden)

    Nikunj J. Aghera

    2012-05-01

    Full Text Available Objective: Sublingual tablets of Losartan Potassium were prepared to improve its bioavailability, to avoid pre-systemic metabolism in the gastrointestinal tract and hepatic first pass elimination. Methods: The Sublingual tablets were prepared by direct compression procedure using different concentration of Starch 1500 and microcrystalline cellulose. Compatibility studies of drug and polymer were performed by FTIR spectroscopy and DSC. Preformulation property of API was evaluated. Postcompressional parameters such disintegration time, wetting time, water absorption ratio, in vitro drug release and in vivo bioavailability study of optimized formulation were determined. Results: FTIR spectroscopy and DSC study revealed that there was no possible interaction between drug and polymers. The precompression parameters were in acceptable range of pharmacopoeial specification. The disintegration time of optimized formulation (F3 was upto 48 sec. The in vitro release of Losartan Potassium was upto 15 min. The percentage relative bioavailability of Losartan Potassium from optimized sublingual tablets was found to be 144.7 %. Conclusions: Sublingual tablets of Losartan Potassium were successfully prepared with improved bioavailability.

  11. FORMULATION AND EVALUATION OF FAST DISSOLVING TABLETS OF TELMISARTAN

    Directory of Open Access Journals (Sweden)

    Kapil Chauhan*, Bharat Parashar, Abhishek Chandel and Varun Thakur

    2013-04-01

    Full Text Available ABSTRACT: The patients with sudden increase blood pressure have markedly reduced function ability and extremely restless, in such cases rapid onset of action is of prime importance. So the patients would be benefited from acute treatment by using Fast dissolving drug delivery system. Telmisartan is an Anti-hypertensive drug which is insoluble in water; hence the drug may be slowly or incompletely dissolves in the gastro-intestinal tract. So the rate of dissolution and therefore its bioavailability is less (bioavailability 42%. In the present study an attempt has been made to prepare. Fast Dissolving tablets of Telmisartan by using Superdisintegrants– Crosscarmellose Sodium, Doshion ,Sodium Starch Glycolate, level of addition to increase the rate of drug release from dosage form to increase the dissolution rate and hence its bioavailability. The tablets were prepared by Direct Compression methods and the prepared blend and tablets were evaluated for their physicochemical properties and In-vitro dissolution study. The evaluation studies were performed such as Weight Variation, Thickness, Hardness, Disintegrating Time, Wetting Time, and In-vitro Drug Release and Stability Study. The Disintegration time of Fast Dissolving tablets were increased by the addition of concentration of Superdisintegrants.

  12. SUPERDISINTEGRANTS IN THE DEVELOPMENT OF ORALLY DISINTEGRATING TABLETS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Nisha Gupta

    2011-11-01

    Full Text Available The desire of improved palatability in orally administered products has prompted the development of numerous formulations with improved performance and acceptability. Orally disintegrating tablets are an emerging trend in novel drug delivery system and have received ever-increasing demand during the last few decades. The field has become a rapidly growing area in the pharmaceutical industry and gaining popularity due to ease of administration and better patient compliance especially for geriatric and pediatric patients. ODTs are solid unit dosage forms, which disintegrates or dissolves rapidly in the mouth without chewing and water. This type of property in dosage form can be attained by addition of different excipients, from which disintegrant is the key adjuvant. In recent years, several newer agents have been developed known as superdisintegrants. Diverse categories of superdisintegrants such as synthetic, semi-synthetic, natural and co-processed blends etc. have been employed to develop effectual mouth dissolving tablets and to overcome the limitations of conventional tablet dosage forms. The objective of the present article is to highlight the various kinds of superdisintegrants along with their role in tablet disintegration and drug release, which are being used in the formulation to provide the safer, effective drug delivery with patient compliance. This review focuses on various synthetic superdisintegrants, natural superdisintegrants from different plant sources, co-processed excipients blend and their efficiency.

  13. Pharmaceutical equivalence of metformin tablets with various binders

    Directory of Open Access Journals (Sweden)

    L. C. Block

    2009-01-01

    Full Text Available

    Metformin hydrochloride is a high-dose drug widely used as an oral anti-hyperglycemic agent. As it is highly crystalline and has poor compaction properties, it is difficult to form tablets by direct compression. The aim of this study was to develop adequate metformin tablets, pharmaceutically equivalent to the reference product, Glucophage® (marketed as Glifage® in Brazil. Metformin 500mg tablets were produced by wet granulation with various binders (A = starch, B = starch 1500®, C = PVP K30®, D = PVP K90®. The tablets were analyzed for their hardness, friability, disintegration, dissolution, content uniformity and dissolution profile (basket apparatus at 50 rpm, pH 6.8 phosphate buffer. The 4 formulations, F1 (5% A and 5% C, F2 (5% B and 5% C, F3 (10% C and F4 (5% D, demonstrated adequate uniformity of content, hardness, friability, disintegration and total drug dissolution after 30 minutes (F1, F2 and F4, and after 60 minutes (F3. The drug release time profiles fitted a Higuchi model (F1, F2 and F3, similarly to the pharmaceutical reference, or a zero order model (F4. The dissolution efficiency for all the formulations was 75%, except for F3 (45%. F1 and F2 were thus equivalent to Glifage®. Keywords: dissolution; metformin; tablet; binder; pharmaceutical equivalence

  14. Optimization of an aqueous tablet-coating process containing carboxymethylated Cassia fistula gum.

    Science.gov (United States)

    Rai, Parshu Ram; Tiwary, Ashok Kumar; Rana, Vikas

    2012-06-01

    The present investigation was aimed at developing and optimizing a simple aqueous tablet-coating formulation and its process. 5-Fluorouracil (5-FU) was used to ascertain the relative lipophilic/hydrophilic behavior of the coating system. Optimization was performed by evaluating the adhesive force strength and cohesive force strength of the tablet coat using a texture analyzer. The in vitro release of 5-FU was found to decrease with an increase in (tablet surface-coat) adhesive force strength. The (tablet-tablet) cohesive force strength was reduced by the addition of magnesium silicate to the coating solution. The addition of magnesium silicate (0.2% w/v) to the carboxymethyl Cassia fistula gum-chitosan (CCG-CH) coating surface significantly inhibited the release of 5-FU possibly due to an increase in the hydrophobic character of the coated tablet surface. This was possible by coating cohesive force strength reduction coating compositions (CCG-CH (70:30) and 0.3% magnesium silicate). Further, the FTIR-ATR and DSC analyses suggested the pivotal role of magnesium silicate in modifying the release of 5-FU from CCG-CH-coated tablets due to hydrogen bonding of its Si-O-Si or Mg-O groups with -OH moieties of CCG-CH.

  15. Continuous twin screw granulation: influence of process variables on granule and tablet quality.

    Science.gov (United States)

    Vercruysse, J; Córdoba Díaz, D; Peeters, E; Fonteyne, M; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

    2012-09-01

    The aim of the current study was to screen theophylline (125 mg) tablets manufactured via twin screw granulation in order to improve process understanding and knowledge of process variables that determine granule and tablet quality. A premix of theophylline anhydrate, α-lactose monohydrate and PVP (ratio: 30/67.5/2.5,w/w) was granulated with demineralized water. Experiments were done using the high-shear wet granulation module (based on twin screw granulation) of the ConsiGma™-25 unit (a continuous tablet manufacturing system) for particle size enlargement. After drying, granules were compressed using a MODUL™ P tablet press (compression force: 10 kN, tablet diameter: 12 mm). Using a D-optimal experimental design, the effect of several process variables (throughput (10-25 kg/h), screw speed (600-950 rpm), screw configuration (number (2, 4, 6 and 12) and angle (30°, 60° and 90°) of kneading elements), barrel temperature (25-40°C) and method of binder addition (dry versus wet)) on the granulation process (torque and temperature increase in barrel wall), granule (particle size distribution, friability and flowability) and tablet (tensile strength, porosity, friability, disintegration time and dissolution) quality was evaluated. The results showed that the quality of granules and tablets can be optimized by adjusting specific process variables (number of kneading elements, barrel temperature and binder addition method) during a granulation process using a continuous twin screw granulator.

  16. National Energy Outlook Modelling System

    Energy Technology Data Exchange (ETDEWEB)

    Volkers, C.M. [ECN Policy Studies, Petten (Netherlands)

    2013-12-15

    For over 20 years, the Energy research Centre of the Netherlands (ECN) has been developing the National Energy Outlook Modelling System (NEOMS) for Energy projections and policy evaluations. NEOMS enables 12 energy models of ECN to exchange data and produce consistent and detailed results.

  17. ABSTRACT MODELS FOR SYSTEM VIRTUALIZATION

    Directory of Open Access Journals (Sweden)

    M. G. Koveshnikov

    2015-05-01

    Full Text Available The paper is dedicated to issues of system objects securing (system files and user system or application configuration files against unauthorized access including denial of service attacks. We have suggested the method and developed abstract system virtualization models, which are used toresearch attack scenarios for different virtualization modes. Estimation for system tools virtualization technology effectiveness is given. Suggested technology is based on redirection of access requests to system objects shared among access subjects. Whole and partial system virtualization modes have been modeled. The difference between them is the following: in the whole virtualization mode all copies of access system objects are created whereon subjects’ requests are redirected including corresponding application objects;in the partial virtualization mode corresponding copies are created only for part of a system, for example, only system objects for applications. Alternative solutions effectiveness is valued relating to different attack scenarios. We consider proprietary and approved technical solution which implements system virtualization method for Microsoft Windows OS family. Administrative simplicity and capabilities of correspondingly designed system objects security tools are illustrated on this example. Practical significance of the suggested security method has been confirmed.

  18. Aerodynamic and Mechanical System Modelling

    DEFF Research Database (Denmark)

    Jørgensen, Martin Felix

    This thesis deals with mechanical multibody-systems applied to the drivetrain of a 500 kW wind turbine. Particular focus has been on gearbox modelling of wind turbines. The main part of the present project involved programming multibody systems to investigate the connection between forces, moments...

  19. Experimental Modeling of Dynamic Systems

    DEFF Research Database (Denmark)

    Knudsen, Morten Haack

    2006-01-01

    An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...

  20. Comparison of novel granulated pellet-containing tablets and traditional pellet-containing tablets by artificial neural networks.

    Science.gov (United States)

    Huang, Ying; Yao, Qinghe; Zhu, Chune; Zhang, Xuan; Qin, Lingzhen; Wang, Qinruo; Pan, Xin; Wu, Chuanbin

    2015-01-01

    Novel granulated pellets technique was adopted to prepare granulated pellet-containing tablets (GPCT). GPCT and traditional pellet-containing tablets (PCT) were prepared according to 29 formulations devised by the Design Expert 7.0, with doxycycline hydrochloride as model drug, blends of Eudragit FS 30D and Eudragit L 30D-55 as coating materials, for the comparison study to confirm the superiority of GPCT during compaction. Eudragit FS 30D content, coating weight gain, tablet hardness and pellet size were chosen as influential factors to investigate the properties and drug release behavior of tablets. The correlation coefficients between the experimental values and the predicted values by artificial neural networks (ANNs) for PCT and GPCT were 0.9474 and 0.9843, respectively, indicating the excellent prediction of ANNs. The similarity factors (f2) for release profiles of GPCT and the corresponding original pellets were higher than those of PCT, suggesting that the excipient layer of granulated pellets absorbed the compressing force and protected the integrity of coating films during compaction.

  1. Identification of anisodamine tablets by Raman and near-infrared spectroscopy with chemometrics.

    Science.gov (United States)

    Li, Lian; Zang, Hengchang; Li, Jun; Chen, Dejun; Li, Tao; Wang, Fengshan

    2014-06-05

    Vibrational spectroscopy including Raman and near-infrared (NIR) spectroscopy has become an attractive tool for pharmaceutical analysis. In this study, effective calibration models for the identification of anisodamine tablet and its counterfeit and the distinguishment of manufacturing plants, based on Raman and NIR spectroscopy, were built, respectively. Anisodamine counterfeit tablets were identified by Raman spectroscopy with correlation coefficient method, and the results showed that the predictive accuracy was 100%. The genuine anisodamine tablets from 5 different manufacturing plants were distinguished by NIR spectroscopy using partial least squares discriminant analysis (PLS-DA) models based on interval principal component analysis (iPCA) method. And the results showed the recognition rate and rejection rate were 100% respectively. In conclusion, Raman spectroscopy and NIR spectroscopy combined with chemometrics are feasible and potential tools for rapid pharmaceutical tablet discrimination.

  2. A comparison of reflectance and transmittance near-infrared spectroscopic techniques in determining drug content in intact tablets.

    Science.gov (United States)

    Thosar, S S; Forbess, R A; Ebube, N K; Chen, Y; Rubinovitz, R L; Kemper, M S; Reier, G E; Wheatley, T A; Shukla, A J

    2001-01-01

    Drug contents of intact tablets were determined using non-destructive near infrared (NIR) reflectance and transmittance spectroscopic techniques. Tablets were compressed from blends of Avicel PH-101 and 0.5% w/w magnesium stearate with varying concentrations of anhydrous theophylline (0, 1, 2, 5, 10, 20 and 40% w/w). Ten tablets from each drug content batch were randomly selected for spectral analysis. Both reflectance and transmittance NIR spectra were obtained from these intact tablets. Actual drug contents of the tablets were then ascertained using a UV-spectrophotometer at 268 nm. Multiple linear regression (MLR) models at 1116 nm and partial least squares (PLS) calibration models were generated from the second derivative spectral data of the tablets in order to predict drug contents of intact tablets. Both the reflectance and the transmittance techniques were able to predict the drug contents in intact tablets over a wide range. However, a comparison of the results of the study indicated that the lowest percent errors of prediction were provided by the PLS calibration models generated from spectral data obtained using the transmittance technique.

  3. An extensible analysable system model

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, Rene Rydhof

    2008-01-01

    , this does not hold for real physical systems. Approaches such as threat modelling try to target the formalisation of the real-world domain, but still are far from the rigid techniques available in security research. Many currently available approaches to assurance of critical infrastructure security...... allows for easy development of analyses for the abstracted systems. We briefly present one application of our approach, namely the analysis of systems for potential insider threats....

  4. FORMULATION AND EVALUATION OF EFFERVESCENT TABLET OF PARACETAMOL AND IBUPROFEN

    OpenAIRE

    Hiren K. Patel; Pankaj V. Chauhan; Kunal N. Patel; Bhavana A. Patel; Poras A. Patel

    2012-01-01

    Recently, fast-dissolving drug delivery system have started gaining popularity and acceptance as newdrug delivery system, because they are easy to administer and lead to better compliance. Usually, elderlypeople experience difficulty in swallowing the tablet. Paracetamol having analgesic, antipyretic effect,they inhibit cyclooxygenase enzyme involved in prostaglandin (PG) synthesis but not in peripheraltissue while Ibuprofen inhibit prostaglandin (PG) synthesis in peripheral tissue so in this...

  5. FORMULATION AND EVALUATION OF EFFERVESCENT TABLETS OF ACECLOFENAC

    OpenAIRE

    Palanisamy P; Rabi Abhishekh; D. Yoganand Kumar

    2011-01-01

    Recently, fast-dissolving drug delivery systems have started gaining popularity and acceptance as new drug delivery systems, because they are easy to administer and lead to better patient compliance. Usually, elderly people experience difficulty in swallowing the tablet. Aceclofenac is a NSAID which has greater inhibitory action against the inducible form of cyclooxygenase (COX-2) which is implicated in the inflammatory response against the constitutive form of this enzyme (COX-1) inhibition....

  6. Monitoring blend potency in a tablet press feed frame using near infrared spectroscopy.

    Science.gov (United States)

    Ward, Howard W; Blackwood, Daniel O; Polizzi, Mark; Clarke, Hugh

    2013-06-01

    A near-infrared (NIR) probe was installed into the feed frame of a rotary tablet press to monitor API concentration as a function of time. A series of step change experimental trials were completed, where a placebo blend was initially charged into the feed frame, and an active blend was layered above. The compression process was initiated, and process parameters, such as mass throughput rate, and feed frame paddle wheel speed were systematically varied. For the range of mass throughput rates studied, excellent correlations were shown between the NIR signal and weight corrected tablet potency from stratified tablet samples. A similar correlation was demonstrated for higher feed frame paddle wheel speeds. However, for lower feed frame paddle wheel speeds, a bias was observed between weight corrected tablet potency and the NIR signal. This finding suggests that compression process parameters, such as paddle wheel rotational speed and NIR probe location, must be optimized for different tablet press geometries to ensure that the NIR process signal can be related to tablet potency. This emerging application of Process Analytical Technology (PAT) may be used to identify powder segregation events during discharge of powder from an intermediate bulk container (IBC) or as a development tool to further understand powder mixing dynamics occurring within the feed frame. This may also be used as a diagnostic tool for fault detection during tablet compression. Finally, this PAT application may also be integrated with the tablet press control system as a gating or reject device for sub or super-potent tablets or enable Real-Time-Release testing (RTRt) through the continuous monitoring of the potency and homogeneity of powder circulating within the feed frame.

  7. Modeling Multi-Level Systems

    CERN Document Server

    Iordache, Octavian

    2011-01-01

    This book is devoted to modeling of multi-level complex systems, a challenging domain for engineers, researchers and entrepreneurs, confronted with the transition from learning and adaptability to evolvability and autonomy for technologies, devices and problem solving methods. Chapter 1 introduces the multi-scale and multi-level systems and highlights their presence in different domains of science and technology. Methodologies as, random systems, non-Archimedean analysis, category theory and specific techniques as model categorification and integrative closure, are presented in chapter 2. Chapters 3 and 4 describe polystochastic models, PSM, and their developments. Categorical formulation of integrative closure offers the general PSM framework which serves as a flexible guideline for a large variety of multi-level modeling problems. Focusing on chemical engineering, pharmaceutical and environmental case studies, the chapters 5 to 8 analyze mixing, turbulent dispersion and entropy production for multi-scale sy...

  8. Prediction of tablet characteristics from residual stress distribution estimated by the finite element method.

    Science.gov (United States)

    Hayashi, Yoshihiro; Miura, Takahiro; Shimada, Takuya; Onuki, Yoshinori; Obata, Yasuko; Takayama, Kozo

    2013-10-01

    Tablet characteristics of tensile strength and disintegration time were predicted using residual stress distribution, simulated by the finite element method (FEM). The Drucker-Prager Cap (DPC) model was selected as the method for modeling the mechanical behavior of pharmaceutical powders composed of lactose (LAC), cornstarch (CS), and microcrystalline cellulose (MCC). The DPC model was calibrated using a direct shear test and analysis of the hardening law of the powder. The constructed DPC model was fed into the analysis using the FEM, and the mechanical behavior of pharmaceutical powders during compaction was analyzed using the FEM. The results revealed that the residual stress distribution of the tablets was uniform when the compression force increased. In particular, the residual stress distribution of tablets composed of equal amounts of LAC, CS, and MCC was more uniform than the tablets composed of 67% LAC and 33% CS, with no MCC. The tensile strength and disintegration time were predicted accurately from the residual stress distribution of tablets using multiple linear regression analysis and partial least squares regression analysis. This suggests that the residual stress distribution of tablets is related closely to the tensile strength and disintegration time.

  9. Clinical pharmacokinetics of buffered propranolol sublingual tablet (Promptol™)-application of a new "physiologically based" model to assess absorption and disposition.

    Science.gov (United States)

    Wang, Yanfeng; Wang, Zhijun; Zuo, Zhong; Tomlinson, Brian; Lee, Benjamin T K; Bolger, Michael B; Chow, Moses S S

    2013-07-01

    Sublingual administration of certain buffered propranolol may improve the rate and extent of absorption compared to oral administration. The main objectives of this study were to (1) compare the plasma propranolol concentrations (Cp-prop) following sublingual administration of a specially buffered formulation (Promptol™) to that following oral administration of Inderal(®) and (2) evaluate the utility of a special pharmacokinetic model in describing the Cp-prop following sublingual administration. Eighteen healthy volunteers received 10 mg sublingual Promptol™ or oral Inderal(®). Multiple Cp-prop were determined and their pharmacokinetics compared. Additional data following sublingual 40 mg Promptol™ or Inderal(®) were utilized for evaluation of a special advanced compartmental absorption and transit (ACAT) model. For model simulation, the physicochemical parameters were imported from AMET predictor, whereas the pharmacokinetic parameters were calculated and optimized by Gastroplus(®). Based on this model, the quantity of drug absorbed via buccal/sublingual mucosa was estimated. Cp-prop was higher at earlier times with 3-fold greater relative bioavailability following sublingual Promptol™ compared to that from oral Inderal(®). The special ACAT model provided excellent goodness of fit of Cp-prop-time curve and estimated a 56.6% increase in absorption rate from Promptol™ and higher initial Cp-prop compared to the regular formulation. The modified ACAT model provided a useful approach to describe sublingual absorption of propranolol and clearly demonstrated an improvement of absorption of Promptol™. The sublingual 10 mg Promptol™ achieved not only a similar systemic exposure as 30 mg oral Inderal(®) but an earlier effective Cp-prop which may be advantageous for certain clinical conditions.

  10. Pure drug nanoparticles in tablets: what are the dissolution limitations?

    Energy Technology Data Exchange (ETDEWEB)

    Heng, Desmond [Institute of Chemical and Engineering Sciences (Singapore); Ogawa, Keiko [Nitto Denko Co. Ltd., Medical Division (Japan); Cutler, David J.; Chan, Hak-Kim, E-mail: kimc@pharm.usyd.edu.a [University of Sydney, Advanced Drug Delivery Group, Faculty of Pharmacy, A15 (Australia); Raper, Judy A. [University of Wollongong, Vice Chancellor' s Unit (Australia); Ye Lin [University of Sydney, School of Aerospace, Mechanical and Mechatronic Engineering (Australia); Yun, Jimmy [Nanomaterials Technology Pty. Ltd. (Singapore)

    2010-06-15

    There has been increasing interests for drug companies to incorporate drug nanoparticles into their existing formulations. However, technical knowledge in this area is still in its infancy and more study needs to be done to stimulate growth in this fledging field. There is a need to scrutinize the performance of pure drug nanoparticles in tablets, particularly relating formulation variables to their dissolution performance. Application of the pure form, synthesized without the use of surfactants or stabilizers, is often preferred to maximize drug loading and also to minimize toxicity. Cefuroxime axetil, a poorly water-soluble cephalosporin antibiotic, was used as the model drug in the formulation development. Drug release rate, tablet disintegration time, tensile strength and energy of failure were predominantly influenced by the amount of super-disintegrant, amount of surfactant, compression force and diluent species, respectively. The compression rate had minimal impact on the responses. The main hurdle confronting the effective use of pure drug nanoparticles in tablets is the difficulty in controlling aggregation in solution, which could potentially be aggravated by the tabletting process. Through the use of elevated levels of surfactants (8 w/w% sodium dodecyl sulphate), drug release from the nanoparticle preparation was enhanced from 58.0 {+-} 2.7% to 72.3 {+-} 0.7% in 10 min. Hence, it is recommended that physical formulations for pure drug nanoparticles be focused on the particle de-aggregation step in solution, if much higher rates are to be desired. In conclusion, even though pure drug nanoparticles could be easily synthesized, limitations from aggregation may need to be overcome, before successful application in tablets can be fully realized.

  11. Biopharmaceutic Risk Assessment of Brand and Generic Lamotrigine Tablets.

    Science.gov (United States)

    Vaithianathan, Soundarya; Raman, Siddarth; Jiang, Wenlei; Ting, Tricia Y; Kane, Maureen A; Polli, James E

    2015-07-06

    The therapeutic equivalence of generic and brand name antiepileptic drugs has been questioned by neurologists and the epilepsy community. A potential contributor to such concerns is pharmaceutical quality. The objective was to assess the biopharmaceutic risk of brand name Lamictal 100 mg tablets and generic lamotrigine 100 mg tablets from several manufacturers. Lamotrigine was characterized in terms of the Biopharmaceutics Classification System (BCS), including aqueous solubility and Caco-2 permeability. A panel of pharmaceutical quality tests was also performed on three batches of Lamictal, three batches of Teva generic, and one batch of each of four other generics: appearance, identity, assay, impurity, uniformity of dosage units, disintegration, dissolution, friability, and loss on drying. These market surveillance results indicate that all brand name and generic lamotrigine 100 mg tablets passed all tests and showed acceptable pharmaceutical quality and low biopharmaceutic risk. Lamotrigine was classified as a BCS class IIb drug, exhibiting pH-dependent aqueous solubility and dissolution. At pH 1.2 and 4.5, lamotrigine exhibited high solubility, whereas lamotrigine exhibited low solubility at pH 6.8, including non-sink dissolution. Lamotrigine showed high Caco-2 permeability. The apparent permeability (Papp) of lamotrigine was (73.7 ± 8.7) × 10(-6) cm/s in the apical-to-basolateral (AP-BL) direction and (41.4 ± 1.6) × 10(-6) cm/s in the BL-AP direction, which were higher than metoprolol's AP-BL Papp of (21.2 ± 0.9) × 10(-6) cm/s and BL-AP Papp of (34.6 ± 4.6) × 10(-6) cm/s. Overall, lamotrigine's favorable biopharmaceutics from a drug substance perspective and favorable quality characteristics from a tablet formulation perspective suggest that multisource lamotrigine tablets exhibit a low biopharmaceutic risk.

  12. Distribution system modeling and analysis

    CERN Document Server

    Kersting, William H

    2002-01-01

    For decades, distribution engineers did not have the sophisticated tools developed for analyzing transmission systems-often they had only their instincts. Things have changed, and we now have computer programs that allow engineers to simulate, analyze, and optimize distribution systems. Powerful as these programs are, however, without a real understanding of the operating characteristics of a distribution system, engineers using the programs can easily make serious errors in their designs and operating procedures.Distribution System Modeling and Analysis helps prevent those errors. It gives re

  13. Breaking of scored tablets : a review

    NARCIS (Netherlands)

    van Santen, E; Barends, D M; Frijlink, H W

    2002-01-01

    The literature was reviewed regarding advantages, problems and performance indicators of score lines. Scored tablets provide dose flexibility, ease of swallowing and may reduce the costs of medication. However, many patients are confronted with scored tablets that are broken unequally and with diffi

  14. Tablet PCs: A Physical Educator's New Clipboard

    Science.gov (United States)

    Nye, Susan B.

    2010-01-01

    Computers in education have come a long way from the abacus of 5,000 years ago to the desktop and laptop computers of today. Computers have transformed the educational environment, and with each new iteration of smaller and more powerful machines come additional advantages for teaching practices. The Tablet PC is one. Tablet PCs are fully…

  15. 21 CFR 520.1510 - Nitenpyram tablets.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... order of a licensed veterinarian. (d) Conditions of use—(1) Dogs—(i) Amount—(A) One 11.4-mg tablet for dogs weighing less than 25 pounds (lb) or one 57-mg tablet for dogs weighing more than 25 lb, as...

  16. Stirling Engine Dynamic System Modeling

    Science.gov (United States)

    Nakis, Christopher G.

    2004-01-01

    The Thermo-Mechanical systems branch at the Glenn Research Center focuses a large amount time on Stirling engines. These engines will be used on missions where solar power is inefficient, especially in deep space. I work with Tim Regan and Ed Lewandowski who are currently developing and validating a mathematical model for the Stirling engines. This model incorporates all aspects of the system including, mechanical, electrical and thermodynamic components. Modeling is done through Simplorer, a program capable of running simulations of the model. Once created and then proven to be accurate, a model is used for developing new ideas for engine design. My largest specific project involves varying key parameters in the model and quantifying the results. This can all be done relatively trouble-free with the help of Simplorer. Once the model is complete, Simplorer will do all the necessary calculations. The more complicated part of this project is determining which parameters to vary. Finding key parameters depends on the potential for a value to be independently altered in the design. For example, a change in one dimension may lead to a proportional change to the rest of the model, and no real progress is made. Also, the ability for a changed value to have a substantial impact on the outputs of the system is important. Results will be condensed into graphs and tables with the purpose of better communication and understanding of the data. With the changing of these parameters, a more optimal design can be created without having to purchase or build any models. Also, hours and hours of results can be simulated in minutes. In the long run, using mathematical models can save time and money. Along with this project, I have many other smaller assignments throughout the summer. My main goal is to assist in the processes of model development, validation and testing.

  17. Product development of pumpkin tablet

    Directory of Open Access Journals (Sweden)

    Kamgoed, T.

    2007-05-01

    Full Text Available The development of pumpkin tablet was studied and the drying conditions of pumpkin using a double drum dryer were optimized. The study factors were drying agents (maltodextrin D.E.13-16 andtapioca flour at different levels (3 and 5%, drying temperatures (130 and 140oC and drum dryer speeds (4 and 5 rpm. The results showed that the optimal conditions were using 3% maltodextrin D.E.13-16, dryingtemperature of 130oC and drum dryer speed of 4 rpm. The moisture, fat, bulk density, reducing sugars and granulometric retention of the obtained pumpkin powder were 3.39%, 1.42%, 1.004 g/ml, 12.63% and 0.67%, respectively and L*, a* and b* values were 73.85, -0.60 and 35.23, respectively. A study of suitable amount of icing sugar using different contents for tablet production (0, 10, 20, 30 and 40% was performedand showed that using 20% icing sugar was the most acceptable. The obtained pumpkin tablet was subjected to chemical, physical and microbiological analysis. The ash, moisture, protein, fat, fiber and carbohydratecontents were 1.87, 3.60, 3.34, 1.00, 2.26 and 87.99%, respectively. The reducing sugars and β-carotene contents were 5.44±0.61% and 3.79±0.57 mg/100g, respectively. The Aw, hardness and solubility were 0.56,3.25 kgf and 25.00 %, respectively. The L*, a* and b* values were 79.85, 0.28 and 23.64, respectively. The total microbial count and the yeast and mould count were <10 CFU/g. The shelf life of the pumpkin tabletwas at least 4 months at room temperature (35±2oC.

  18. Disulfiram-loaded immediate and extended release vaginal tablets for the localised treatment of cervical cancer.

    Science.gov (United States)

    Baffoe, Clara S; Nguyen, Nhi; Boyd, Peter; Wang, Weiguang; Morris, Mark; McConville, Christopher

    2015-02-01

    To develop and manufacture both immediate and sustained release vaginal tablets containing the anticancer drug disulfiram, which has the potential to be used as a non-invasive treatment for cervical cancer. Disulfiram-loaded vaginal tablets were manufactured at pilot scale using the direct compression method. These tablets were tested in accordance with the European Pharmacopeia testing of solid dosage form guidelines. They were also tested using a biorelevant dissolution method as well as a dual-chambered release model designed to better mimic the dynamic nature of the vaginal vault. We have developed both immediate and sustained release vaginal tablets, which when manufactured at pilot scale are within the limits set by the European Pharmacopeia for the testing of solid dosage forms. Furthermore, these tablets are capable of releasing disulfiram in vitro using the dual-chambered release model at levels 25,000 times and 35,000 times greater than its IC50 concentration for the HeLa cervical cancer cell line. The successful pilot manufacture and testing of both the immediate and sustained release disulfiram-loaded vaginal tablets warrant further investigation, using an in-vivo model, to assess their potential for use as a non-invasive treatment option for cervical cancer. © 2014 Royal Pharmaceutical Society.

  19. A Tablet for Healthy Ageing: The Effect of a Tablet Computer Training Intervention on Cognitive Abilities in Older Adults.

    Science.gov (United States)

    Vaportzis, Eleftheria; Martin, Mike; Gow, Alan J

    2017-08-01

    To test the efficacy of a tablet computer training intervention to improve cognitive abilities of older adults. Prospective randomized controlled trial. Community-based aging intervention study, Edinburgh, UK. Forty-eight healthy older adults aged 65 to 76 years were recruited at baseline with no or minimal tablet experience; 43 completed follow-up testing. Twenty-two participants attended a weekly 2-hour class for 10 weeks during which they learned how to use a tablet and various applications on it. A battery of cognitive tests from the WAIS-IV measuring the domains of Verbal Comprehension, Perceptual Processing, Working Memory, and Processing Speed, as well as health, psychological, and well-being measures. A 2 × 2 mixed model ANOVA suggested that the tablet intervention group (N = 22) showed greater improvements in Processing Speed (η(2) = 0.10) compared with controls (N = 21), but did not differ in Verbal Comprehension, Perceptual Processing, or Working Memory (η(2) ranged from -0.03 to 0.04). Engagement in a new mentally challenging activity (tablet training) was associated with improved processing speed. Acquiring skills in later life, including those related to adopting new technologies, may therefore have the potential to reduce or delay cognitive changes associated with ageing. It is important to understand how the development of these skills might further facilitate everyday activities, and also improve older adults' quality of life. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Kinetic Modeling of Biological Systems

    Energy Technology Data Exchange (ETDEWEB)

    Resat, Haluk; Petzold, Linda; Pettigrew, Michel F.

    2009-04-21

    The dynamics of how its constituent components interact define the spatio-temporal response of a natural system to stimuli. Modeling the kinetics of the processes that represent a biophysical system has long been pursued with the aim of improving our understanding of the studied system. Due to the unique properties of biological systems, in addition to the usual difficulties faced in modeling the dynamics of physical or chemical systems, biological simulations encounter difficulties that result from intrinsic multiscale and stochastic nature of the biological processes. This chapter discusses the implications for simulation of models involving interacting species with very low copy numbers, which often occur in biological systems and give rise to significant relative fluctuations. The conditions necessitating the use of stochastic kinetic simulation methods and the mathematical foundations of the stochastic simulation algorithms are presented. How the well-organized structural hierarchies often seen in biological systems can lead to multiscale problems, and possible ways to address the encountered computational difficulties are discussed. We present the details of the existing kinetic simulation methods, and discuss their strengths and shortcomings. A list of the publicly available kinetic simulation tools and our reflections for future prospects are also provided.

  1. FORMULATION AND EVALUATION OF SUSTAINED RELEASE TABLET OF DILTIAZEM HYDROCHLORIDE BY MELT GRANULATION TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Birajdar Ganesh

    2013-07-01

    Full Text Available The objective behind present study was to formulate and evaluate sustained release tablet of Diltiazem hydrochloride by using different polymers by melt granulation technology and to study the effect of various concentrations of polymers on release rate from tablet. Tablets were prepared using bees wax, carnauba wax, paraffin wax as release ratardent polymers. The drug and excipient compatibility study was done by FTIR method using KBr pellet method. The granules prepared by melt granulation technique evaluated for characterization such as bulk density, tapped density, hausners ratio, angle of repose, cars index all granules shows good flow property. The tablet of Diltiazem HCL evaluated for characterization such as hardness, friability, weight variation and content uniformity all tablets shows sufficient hardness and friability shows that tablets are having sufficient strength. All results were satisfactory. The in vitro drug release studies for the prepared formulation were conducted for a period of 12 h using an EDT 08LX dissolution tester USP Type - II apparatus (rotating paddle set at 100 rpm and a temperature of 37 ± 0.5°C formulation was placed in the 900 ml of the medium. For first 2 h tablet was placed in 1.2 pH acidic medium which was replaced with 7.4 pH phosphate buffer for remaining 10 h. From the dissolution study and comparative graph it was concluded that increase in concentration of wax shows decrease in drug release from tablet. Batch F3 shows 99.84 % drug release at 12 h. In vitro release data of optimized formulations (Batch F3 was fitted to various kinetic models like zero order, first order, Higuchi, korsmeyer-peppas and pass Higuchi model as it has highest r2 value (0.955 among all models.

  2. Orodispersible tablets of Lamotrigine: preparation and evaluation

    Directory of Open Access Journals (Sweden)

    Anand Patel

    2014-08-01

    Full Text Available The aim of the present research was to prepare orodispersible tablets of Lamotrigine for applications in epilepsy and convulsion related problems. Fast action onset is highly desirable in the control of this type of disease condition. All tablets were prepared by solid dispersion method using mannitol and synthetic superdisintegrants like Explotab, Cross Povidone and Micro Crystalline Cellulose. The different powder blends were evaluated for pre-formulation parameters. Effect of superdisintegrants on wetting, disintegration and dissolution parameters was studied. The tablets were evaluated for various parameters like wetting time, hardness, friability, drug content, disintegration and in vitro dissolution. Tablets with Explotab have shown good disintegrating features, also the dispersion not showing any bitter taste; indicate the capability of Vanilla used, as taste masking agents. Almost more than 99% of drug was released from the formulation(F4 within 27 min. Tablets have shown no appreciable changes with respect to physical appearance, drug content, disintegration time, and dissolution profiles.

  3. Executive Information Systems' Multidimensional Models

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Executive Information Systems are design to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing, integrating and presenting data in such a way that the organizational knowledge filters can easily associate with this data and turn it into information for the organization. These technologies are known as Business Intelligence Tools. But in order to build analytic reports for Executive Information Systems (EIS in an organization we need to design a multidimensional model based on the business model from the organization. This paper presents some multidimensional models that can be used in EIS development and propose a new model that is suitable for strategic business requests.

  4. Numerical Modeling of Microelectrochemical Systems

    DEFF Research Database (Denmark)

    Adesokan, Bolaji James

    for the reactants in the bulk electrolyte that are traveling waves. The first paper presents the mathematical model which describes an electrochemical system and simulates an electroanalytical technique called cyclic voltammetry. The model is governed by a system of advection–diffusion equations with a nonlinear...... reaction term at the boundary. We investigate the effect of flow rates, scan rates, and concentration on the cyclic voltammetry. We establish that high flow rates lead to the reduced hysteresis in the cyclic voltammetry curves and increasing scan rates lead to more pronounced current peaks. The final part...... of the paper shows that the response current in a cyclic voltammetry increases proportionally to the electrolyte concentration. In the second paper we present an experiment of an electrochemical system in a microfluidc system and compare the result to the numerical solutions. We investigate how the position...

  5. FORMULASI TABLET SERBUK PISANG RAJA (Musa xparadisiaca AAB SEBAGAI PENUTUP TUKAK LAMBUNG PADA TIKUS

    Directory of Open Access Journals (Sweden)

    Iis Wahyuningsih

    2012-05-01

    Full Text Available Mucoadhesive is a topic of current interest in the design of drug delivery system and treatment of peptic ulcers. This concept is based on the strength of adhesion of a protective material to the mucosa. King Banana (Musa xparadisiaca AAB is often used in the treatment of abdominal pain. It has been suspected having muchoadhesive strength to cover peptic ulcer. The study was armed to formulate king banana tablet which has muchoadhesive ability to protect gastric mucosa become ulcer. The aim of peptic ulcer cover test was to see the ability of king banana tablet to covered ulcer at the groups test that received different treatment of the negative control group (solvent, the banana tablet suspension group, and sucralfate group. The ulcer severity was determined by scoring method. All experimental data were tested by SPSS analytical statistics. The result showed that king banana tablet has similar strength to peptic ulcer cover of sucralfat and not significantly different.

  6. Investigation and Evaluation of an in Situ Interpolymer Complex of Carbopol with Polyvinylpyrrolidone as a Matrix for Gastroretentive Tablets of Ranitidine Hydrochloride.

    Science.gov (United States)

    Yusif, Rehab Mohammad; Abu Hashim, Irhan Ibrahim; Mohamed, Elham Abdelmonem; El Rakhawy, Mohamed Magdy

    2016-01-01

    Carbopol (CP) is a biocompatible bioadhesive polymer used as a matrix for gastroretentive (GR) tablets, however, its rapid hydration shortens its bioadhesion and floating when incorporated in effervescent formulae. The interpolymer complexation of CP with polyvinylpyrrolidone (PVP) significantly reduced the excessive hydration of CP, prolonging floating and maintaining the mucoadhesiveness. In early attempts, a lengthy process was followed to prepare such an interpolymer complex. In this study, an in situ interpolymer complexation between CP and two grades of PVP (K25 and K90) in 0.1 N HCl was investigated and characterized by Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Hence, directly compressed GR tablets of different combinations of PVP and CP with sodium bicarbonate (SB) as an effervescent agent were examined for prolonged gastroretention and sustained release of ranitidine hydrochloride (RHCl) as a model drug. Tablets were evaluated for in vitro buoyancy, bioadhesiveness, swelling, and drug release in 0.1 N HCl. All GR tablets containing PVP-CP combinations achieved more prolonged floating (>24 h) than CP tablets (5.2 h). Their bioadhesiveness, swelling, and drug release were dependent on the PVP molecular weight and its ratio to CP. Drug release profiles of all formulae followed non-Fickian diffusion. Formula containing the PVP K90-CP combination at a respective ratio of 1 : 3 (P90C13) was a promising system, exhibiting good floating and bioadhesive properties as well as sustained drug release. Abdominal X-ray imaging of P90C13 formula, loaded with barium sulfate, in six healthy volunteers showed a mean gastric retention period of 6.8±0.3 h.

  7. Quark Model and multiquark system

    CERN Document Server

    da Silva, Cristiane Oldoni

    2010-01-01

    The discovery of many particles, especially in the 50's, when the firsts accelerators appeared, caused the searching for a model that would describe in a simple form the whole of known particles. The Quark Model, based in the mathematical structures of group theory, provided in the beginning of the 60's a simplified description of hadronic matter already known, proposing that three particles, called quarks, would originate all the observed hadrons. This model was able to preview the existence of particles that were later detected, confirming its consistency. Extensions of the Quark Model were made in the beginning of the 70's, focusing in describing observed particles that were excited states of the fundamental particles and others that presented new quantum numbers (flavors). Recently, exotic states as tetraquarks and pentaquarks types, also called multiquarks systems, previewed by the model, were observed, what renewed the interest in the way as quarks are confined inside the hadrons. In this article we pre...

  8. From colloidal nanoparticles to a single crystal: new insights into the formation of nacre's aragonite tablets.

    Science.gov (United States)

    Zhang, Gangsheng; Xu, Jun

    2013-04-01

    Nacre has long served as a model for understanding the biomineralization mechanism and designing bio-inspired materials. However, its basic building blocks, the aragonite tablets, are still under debate in terms of their fine structure at the nanoscale and corresponding formation mechanism. Here, using a field emission scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), and X-ray diffractometer, we comparatively investigate the immature and mature tablet from the green mussel's nacre. We find that: (1) the early immature tablet consists of closely-packed colloidal nanoparticles, which contain nanocrystals surrounded by the amorphous calcium carbonate (ACC) phase. Moreover, these nanocrystals are generally different in shape, size, and orientation; (2) the immature tablet can grow via oriented attachment besides via transformation of the ACC phase; and (3) with growth, the colloidal nanoparticles gradually increase in crystallinity and size until fully crystallized and fused together, leading to a mature tablet that is a monolithic single crystal of aragonite. Based on these findings, we propose a new model showing how the mature tablet evolves from the primary colloidal ACC nanoparticles. We expect this work will provide new insights into the formation of single crystal biominerals via the amorphous precursor route.

  9. Mathematical tablets from Tell Harmal

    CERN Document Server

    Gonçalves, Carlos

    2015-01-01

    This work offers a re-edition of twelve mathematical tablets from the site of Tell Harmal, in the borders of present-day Baghdad. In ancient times, Tell Harmal was Šaduppûm, a city representative of the region of the Diyala river and of the kingdom of Ešnunna, to which it belonged for a time. These twelve tablets were originally published in separate articles in the beginning of the 1950s and mostly contain solved problem texts. Some of the problems deal with abstract matters such as triangles and rectangles with no reference to daily life, while others are stated in explicitly empirical contexts, such as the transportation of a load of bricks, the size of a vessel, the number of men needed to build a wall and the acquisition of oil and lard. This new edition of the texts is the first to group them, and takes into account all the recent developments of the research in the history of Mesopotamian mathematics. Its introductory chapters are directed to readers interested in an overview of the mathematical con...

  10. Adapting to the surface: A comparison of handwriting measures when writing on a tablet computer and on paper.

    Science.gov (United States)

    Gerth, Sabrina; Dolk, Thomas; Klassert, Annegret; Fliesser, Michael; Fischer, Martin H; Nottbusch, Guido; Festman, Julia

    2016-08-01

    Our study addresses the following research questions: Are there differences between handwriting movements on paper and on a tablet computer? Can experienced writers, such as most adults, adapt their graphomotor execution during writing to a rather unfamiliar surface for instance a tablet computer? We examined the handwriting performance of adults in three tasks with different complexity: (a) graphomotor abilities, (b) visuomotor abilities and (c) handwriting. Each participant performed each task twice, once on paper and once on a tablet computer with a pen. We tested 25 participants by measuring their writing duration, in air time, number of pen lifts, writing velocity and number of inversions in velocity. The data were analyzed using linear mixed-effects modeling with repeated measures. Our results reveal differences between writing on paper and on a tablet computer which were partly task-dependent. Our findings also show that participants were able to adapt their graphomotor execution to the smoother surface of the tablet computer during the tasks.

  11. Orodispersible tablets: A new trend in drug delivery

    OpenAIRE

    Dey, Paramita; Maiti, Sabyasachi

    2010-01-01

    The most common and preferred route of drug administration is through the oral route. Orodispersible tablets are gaining importance among novel oral drug-delivery system as they have improved patient compliance and have some additional advantages compared to other oral formulation. They are also solid unit dosage forms, which disintegrate in the mouth within a minute in the presence of saliva due to super disintegrants in the formulation. Thus this type of drug delivery helps a proper peroral...

  12. The reliability of tablet computers in depicting maxillofacial radiographic landmarks

    OpenAIRE

    2015-01-01

    Purpose This study was performed to evaluate the reliability of the identification of anatomical landmarks in panoramic and lateral cephalometric radiographs on a standard medical grade picture archiving communication system (PACS) monitor and a tablet computer (iPad 5). Materials and Methods A total of 1000 radiographs, including 500 panoramic and 500 lateral cephalometric radiographs, were retrieved from the de-identified dataset of the archive of the Section of Oral and Maxillofacial Radio...

  13. Relationship between tablet splitting and compliance, drug acquisition cost, and patient acceptance.

    Science.gov (United States)

    Fawell, N G; Cookson, T L; Scranton, S S

    1999-12-15

    As managed care pharmacy continues to grow and medication costs increase, pharmacy managers are continually looking for ways to reengineer distributive services to provide the most cost-effective care. In an effort to save money, the San Diego Veterans Affairs Healthcare System (SDVAHS) and other health systems have implemented tablet-splitting programs targeted at high-cost and widely prescribed medications. Despite this growing practice, published research examining the effects on compliance rates, patient acceptance, and actual cost savings is lacking. A recent computer-assisted literature search revealed only one study of tablet splitting that addressed patient compliance and acceptance. In that study, patients taking lovastatin and using a tablet splitter were mailed a questionnaire to assess their impressions of tablet splitting. A majority of the patients found tablet splitters easy to use and reported that compliance was not hindered. However, compliance was subjectively evaluated through patients' responses to questions; actual tablet counts were not performed. Furthermore, actual cost savings (if any) were not determined.

  14. GENERIC model for multiphase systems

    NARCIS (Netherlands)

    Sagis, L.M.C.

    2010-01-01

    GENERIC is a nonequilibrium thermodynamic formalism in which the dynamic behavior of a system is described by a single compact equation involving two types of brackets: a Poisson bracket and a dissipative bracket. This formalism has proved to be a very powerful instrument to model the dynamic behavi

  15. Emergency CT brain: preliminary interpretation with a tablet device: image quality and diagnostic performance of the Apple iPad.

    LENUS (Irish Health Repository)

    Mc Laughlin, Patrick

    2012-04-01

    Tablet devices have recently been used in radiological image interpretation because they have a display resolution comparable to desktop LCD monitors. We identified a need to examine tablet display performance prior to their use in preliminary interpretation of radiological images. We compared the spatial and contrast resolution of a commercially available tablet display with a diagnostic grade 2 megapixel monochrome LCD using a contrast detail phantom. We also recorded reporting discrepancies, using the ACR RADPEER system, between preliminary interpretation of 100 emergency CT brain examinations on the tablet display and formal review on a diagnostic LCD. The iPad display performed inferiorly to the diagnostic monochrome display without the ability to zoom. When the software zoom function was enabled on the tablet device, comparable contrast detail phantom scores of 163 vs 165 points were achieved. No reporting discrepancies were encountered during the interpretation of 43 normal examinations and five cases of acute intracranial hemorrhage. There were seven RADPEER2 (understandable) misses when using the iPad display and 12 with the diagnostic LCD. Use of software zoom in the tablet device improved its contrast detail phantom score. The tablet allowed satisfactory identification of acute CT brain findings, but additional research will be required to examine the cause of "understandable" reporting discrepancies that occur when using tablet devices.

  16. Effect of the External Lubrication Method for a Rotary Tablet Press on the Adhesion of the Film Coating Layer.

    Science.gov (United States)

    Kondo, Hisami; Toyota, Hiroyasu; Kamiya, Takayuki; Yamashita, Kazunari; Hakomori, Tadashi; Imoto, Junko; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2017-01-01

    External lubrication is a useful method which reduces the adhesion of powder to punches and dies by spraying lubricants during the tableting process. However, no information is available on whether the tablets prepared using an external lubrication system can be applicable for a film coating process. In this study, we evaluated the adhesion force of the film coating layer to the surface of tablets prepared using an external lubrication method, compared with those prepared using internal lubrication method. We also evaluated wettability, roughness and lubricant distribution state on the tablet surface before film coating, and investigated the relationship between peeling of the film coating layer and these tablet surface properties. Increasing lubrication through the external lubrication method decreased wettability of the tablet surface. However, no change was observed in the adhesion force of the film coating layer. On the other hand, increasing lubrication through the internal lubrication method, decreased both wettability of the tablet surface and the adhesion force of the film coating layer. The magnesium stearate distribution state on the tablet surface was assessed using an X-ray fluorescent analyzer and lubricant agglomerates were observed in the case of the internal lubrication method. However, the lubricant was uniformly dispersed in the external lubrication samples. These results indicate that the distribution state of the lubricant affects the adhesion force of the film coating layer, and external lubrication maintained sufficient lubricity and adhesion force of the film coating layer with a small amount of lubricant.

  17. Fast assessment of the surface distribution of API and excipients in tablets using NIR-hyperspectral imaging.

    Science.gov (United States)

    Franch-Lage, Felicidad; Amigo, José Manuel; Skibsted, Erik; Maspoch, Santiago; Coello, Jordi

    2011-06-15

    The inclusion of hyperspectral imaging systems in the manufacturing and development of pharmaceutical products is allowing a successful improvement in the quality control of solid dosage forms. The correct distribution not only of active pharmaceutical ingredient (API) but also of the rest of excipients is essential to assure the correct behavior of the tablet when ingested. This is especially relevant in tablets with low content of potent APIs, in which the prescribed intake dosage frequently corresponds to half-a-tablet. Therefore, the aim of this work is to study the surface distribution of the compounds in tablets with low API content. The proposed procedure includes the scanning of the tablet surface using near infrared hyperspectral spectroscopy in association with multivariate curve resolution (MCR) techniques to obtain selective pictures for each individual compound and to allow the fast assessment of their distribution in the measured surface. As an example, a set of commercial Lorazepam tablets (approximately 1% mass fraction of API, and four excipients) were analyzed. The results obtained show the capacity of the proposed methodology as an expedite approach to evaluate the uniformity of the contents between and within tablets. A method to estimate the homogeneity distribution of API in the two halves of the tablet is also proposed.

  18. NIR hyperspectral imaging to evaluate degradation in captopril commercial tablets.

    Science.gov (United States)

    França, Leandro de Moura; Pimentel, Maria Fernanda; Simões, Simone da Silva; Grangeiro, Severino; Prats-Montalbán, José M; Ferrer, Alberto

    2016-07-01

    Pharmaceutical quality control is important for improving the effectiveness, purity and safety of drugs, as well as for the prevention or control of drug degradation. In the present work, near infrared hyperspectral images (HSI-NIR) of tablets with different expiration dates were employed to evaluate the degradation of captopril into captopril disulfide in different layers, on the top and on the bottom surfaces of the tablets. Multivariate curve resolution (MCR) models were used to extract the concentration distribution maps from the hyperspectral images. Afterward, multivariate image techniques were applied to the concentration distribution maps (CDMs), to extract features and build models relating the main characteristics of the images to their corresponding manufacturing dates. Resolution methods followed by extracting features were able to estimate the tablet manufacture date with a prediction error of 120days. The model developed could be useful to evaluate whether a sample shows a degradation pattern consistent with the date of manufacturing or to detect abnormal behaviors in the natural degradation process of the sample. The information provided by the HIS-NIR is important for the development of the process (QbD), looking inside the formulation, revealing the behavior of the active pharmaceutical ingredient (API) during the product's shelf life. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Cotangent Models for Integrable Systems

    Science.gov (United States)

    Kiesenhofer, Anna; Miranda, Eva

    2017-03-01

    We associate cotangent models to a neighbourhood of a Liouville torus in symplectic and Poisson manifolds focusing on b-Poisson/ b-symplectic manifolds. The semilocal equivalence with such models uses the corresponding action-angle theorems in these settings: the theorem of Liouville-Mineur-Arnold for symplectic manifolds and an action-angle theorem for regular Liouville tori in Poisson manifolds (Laurent- Gengoux et al., IntMath Res Notices IMRN 8: 1839-1869, 2011). Our models comprise regular Liouville tori of Poisson manifolds but also consider the Liouville tori on the singular locus of a b-Poisson manifold. For this latter class of Poisson structures we define a twisted cotangent model. The equivalence with this twisted cotangent model is given by an action-angle theorem recently proved by the authors and Scott (Math. Pures Appl. (9) 105(1):66-85, 2016). This viewpoint of cotangent models provides a new machinery to construct examples of integrable systems, which are especially valuable in the b-symplectic case where not many sources of examples are known. At the end of the paper we introduce non-degenerate singularities as lifted cotangent models on b-symplectic manifolds and discuss some generalizations of these models to general Poisson manifolds.

  20. Bioavailability of hydrochlorothiazide from isomalt-based moulded tablets.

    Science.gov (United States)

    Ndindayino, F; Vervaet, C; Van den Mooter, G; Remon, J P

    2002-10-10

    The bioavailability of hydrochlorothiazide (HCT) from moulded isomalt-based tablets was evaluated after oral administration of 50 mg HCT to healthy volunteers as an oral moulded tablet and as a lozenge, in comparison with a conventional tablet formulation (Dichlotride 50 mg). Moulded tablets had a high relative bioavailability (F(rel)) as the pharmacokinetic parameters (C(max), t(max), t(1/2), AUC(0-->24 h)) determined from HCT plasma concentration versus time profiles were not significantly different (P>0.05; two-way ANOVA) in comparison with the conventional tablet. The relative bioavailability of the moulded tablet administered as a lozenge and as an oral tablet was 106.2+/-30.9% and 89.4+/-25.9%, respectively, in relation to the conventional tablet formulation. Direct moulding of isomalt tablets proved to be a suitable technique to administer a poorly soluble drug either as a conventional tablet or as a lozenge.

  1. INTEGRATED HYDROGEN STORAGE SYSTEM MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, B

    2007-11-16

    Hydrogen storage is recognized as a key technical hurdle that must be overcome for the realization of hydrogen powered vehicles. Metal hydrides and their doped variants have shown great promise as a storage material and significant advances have been made with this technology. In any practical storage system the rate of H2 uptake will be governed by all processes that affect the rate of mass transport through the bed and into the particles. These coupled processes include heat and mass transfer as well as chemical kinetics and equilibrium. However, with few exceptions, studies of metal hydrides have focused primarily on fundamental properties associated with hydrogen storage capacity and kinetics. A full understanding of the complex interplay of physical processes that occur during the charging and discharging of a practical storage system requires models that integrate the salient phenomena. For example, in the case of sodium alanate, the size of NaAlH4 crystals is on the order of 300nm and the size of polycrystalline particles may be approximately 10 times larger ({approx}3,000nm). For the bed volume to be as small as possible, it is necessary to densely pack the hydride particles. Even so, in packed beds composed of NaAlH{sub 4} particles alone, it has been observed that the void fraction is still approximately 50-60%. Because of the large void fraction and particle to particle thermal contact resistance, the thermal conductivity of the hydride is very low, on the order of 0.2 W/m-{sup o}C, Gross, Majzoub, Thomas and Sandrock [2002]. The chemical reaction for hydrogen loading is exothermic. Based on the data in Gross [2003], on the order of 10{sup 8}J of heat of is released for the uptake of 5 kg of H{sub 2}2 and complete conversion of NaH to NaAlH{sub 4}. Since the hydride reaction transitions from hydrogen loading to discharge at elevated temperatures, it is essential to control the temperature of the bed. However, the low thermal conductivity of the hydride

  2. Probabilistic models for feedback systems.

    Energy Technology Data Exchange (ETDEWEB)

    Grace, Matthew D.; Boggs, Paul T.

    2011-02-01

    In previous work, we developed a Bayesian-based methodology to analyze the reliability of hierarchical systems. The output of the procedure is a statistical distribution of the reliability, thus allowing many questions to be answered. The principal advantage of the approach is that along with an estimate of the reliability, we also can provide statements of confidence in the results. The model is quite general in that it allows general representations of all of the distributions involved, it incorporates prior knowledge into the models, it allows errors in the 'engineered' nodes of a system to be determined by the data, and leads to the ability to determine optimal testing strategies. In this report, we provide the preliminary steps necessary to extend this approach to systems with feedback. Feedback is an essential component of 'complexity' and provides interesting challenges in modeling the time-dependent action of a feedback loop. We provide a mechanism for doing this and analyze a simple case. We then consider some extensions to more interesting examples with local control affecting the entire system. Finally, a discussion of the status of the research is also included.

  3. Modeling Advance Life Support Systems

    Science.gov (United States)

    Pitts, Marvin; Sager, John; Loader, Coleen; Drysdale, Alan

    1996-01-01

    Activities this summer consisted of two projects that involved computer simulation of bioregenerative life support systems for space habitats. Students in the Space Life Science Training Program (SLSTP) used the simulation, space station, to learn about relationships between humans, fish, plants, and microorganisms in a closed environment. One student complete a six week project to modify the simulation by converting the microbes from anaerobic to aerobic, and then balancing the simulation's life support system. A detailed computer simulation of a closed lunar station using bioregenerative life support was attempted, but there was not enough known about system restraints and constants in plant growth, bioreactor design for space habitats and food preparation to develop an integrated model with any confidence. Instead of a completed detailed model with broad assumptions concerning the unknown system parameters, a framework for an integrated model was outlined and work begun on plant and bioreactor simulations. The NASA sponsors and the summer Fell were satisfied with the progress made during the 10 weeks, and we have planned future cooperative work.

  4. Minisuperspace models of discrete systems

    CERN Document Server

    Baytaş, Bekir

    2016-01-01

    A discrete quantum spin system is presented in which several modern methods of canonical quantum gravity can be tested with promising results. In particular, features of interacting dynamics are analyzed with an emphasis on homogeneous configurations and the dynamical building-up and stability of long-range correlations. Different types of homogeneous minisuperspace models are introduced for the system, including one based on condensate states, and shown to capture different aspects of the discrete system. They are evaluated with effective methods and by means of continuum limits, showing good agreement with operator calculations whenever the latter are available. As a possibly quite general result, it is concluded that an analysis of the building-up of long-range correlations in discrete systems requires non-perturbative solutions of the dynamical equations. Some questions related to stability can be analyzed perturbatively, but suggest that matter couplings may be relevant for this question in the context o...

  5. Theoretical analysis of tablet hardness prediction using chemoinformetric near-infrared spectroscopy.

    Science.gov (United States)

    Tanabe, Hideaki; Otsuka, Kuniko; Otsuka, Makoto

    2007-07-01

    In order to clarify the theoretical basis of the variability in the measurement of tablet hardness by compression pressure, NIR spectroscopic methods were used to predict tablet hardness of the formulations. Tablets (200 mg, 8 mm in diameter) consisting of berberine chloride, lactose, and potato starch were formed at various compression pressures (59, 78, 98, 127, 195 MPa). The hardness and the distribution of micropores were measured. The reflectance NIR spectra of various compressed tablets were used as a calibration set to establish a calibration model to predict tablet hardness by principal component regression (PCR) analysis. The distribution of micropores was shifted to a smaller pore size with increasing compression pressure. The total pore volume of tablets decreased as the compression pressure increased. The hardness increased as the compression pressure increased. The hardness could be predicted using a calibration model consisting of 7 principal components (PCs) obtained by PCR. The relationship between the predicted and the actual hardness values exhibited a straight line, an R(2) of 0.925. In order to understand the theoretical analysis (scientific background) of calibration models used to evaluate tablet hardness, the standard error of cross validation (SEV) values, the loading vectors of each PC and the regression vector were investigated. The result obtained with the calibration models for hardness suggested that the regression vector might involve physical and chemical factors. In contrast, the porosity could be predicted using a calibration model composed of 2 PCs. The relationship between the predicted and the actual total pore volume showed a straight line with R(2) = 0.801. The regression vector of the total pore volume might be due to physical factors.

  6. First Experiments with the Tango Tablet for Indoor Scanning

    Science.gov (United States)

    Diakité, Abdoulaye A.; Zlatanova, Sisi

    2016-06-01

    During the last two decades, the third dimension took an important place in the heart of every multimedia. While the 3D technologies mainly used to be tools and subject for researchers, they are becoming commercially available to large public. To make it even more accessible, the Project Tango, leaded by Google, integrates in a simple Android tablet sensors that are able to perform acquisition of the 3D information of a real life scene. This makes it possible for a large number of applications to have access to it, ranging from gaming to indoor navigation, including virtual and augmented reality. In this paper we investigate the ability of the Tango tablet to perform the acquisition of indoor building environment to support application such as indoor navigation. We proceed to several scans in different buildings and we study the characteristics of the output models.

  7. simuwatt - A Tablet Based Electronic Auditing Tool

    Energy Technology Data Exchange (ETDEWEB)

    Macumber, Daniel; Parker, Andrew; Lisell, Lars; Metzger, Ian; Brown, Matthew

    2014-05-08

    'simuwatt Energy Auditor' (TM) is a new tablet-based electronic auditing tool that is designed to dramatically reduce the time and cost to perform investment-grade audits and improve quality and consistency. The tool uses the U.S. Department of Energy's OpenStudio modeling platform and integrated Building Component Library to automate modeling and analysis. simuwatt's software-guided workflow helps users gather required data, and provides the data in a standard electronic format that is automatically converted to a baseline OpenStudio model for energy analysis. The baseline energy model is calibrated against actual monthly energy use to ASHRAE Standard 14 guidelines. Energy conservation measures from the Building Component Library are then evaluated using OpenStudio's parametric analysis capability. Automated reporting creates audit documents that describe recommended packages of energy conservation measures. The development of this tool was partially funded by the U.S. Department of Defense's Environmental Security Technology Certification Program. As part of this program, the tool is being tested at 13 buildings on 5 Department of Defense sites across the United States. Results of the first simuwatt audit tool demonstration are presented in this paper.

  8. Teach yourself visually Windows 8 tablets

    CERN Document Server

    McFedries, Paul

    2012-01-01

    A visual guide to all the features of the new Windows 8 Tablet This must-have resource features visually rich, step-by-step instructions that show you how to get the most enjoyment from your Windows 8 tablet. Learn about the exciting new Metro UI, optimized specifically for touch devices. The most popular and commonly used apps and functions are covered too, along with the basics of syncing with a network, setting up e-mail, watching videos, listening to music, and common productivity tasks. This book provides all the guidance needed to enjoy all the best the new Windows 8 tablets have to offe

  9. Portable Tablets in Science Museum Learning

    DEFF Research Database (Denmark)

    Gronemann, Sigurd Trolle

    2016-01-01

    Despite the increasing use of portable tablets in learning, their impact has received little attention in research. In five different projects, this media-ethnographic and design-based analysis of the use of portable tablets as a learning resource in science museums investigates how young people......’s learning with portable tablets matches the intentions of the museums. By applying media and information literacy (MIL) components as analytical dimensions, a pattern of discrepancies between young people’s expectations, their actual learning and the museums’ approaches to framing such learning...

  10. A new formulation of fenofibrate: suprabioavailable tablets.

    Science.gov (United States)

    Guichard, J P; Blouquin, P; Qing, Y

    2000-01-01

    The rationale for, and development of, a new suprabioavailable fenofibrate tablet formulation is described. The new suprabioavailable tablet formulation combines well-established micronisation technology with a new micro-coating process. The new formulation provides more predictable and reliable drug absorption. Owing to the strong relationship between the fenofibrate dissolution performance and its oral bioavailability, equivalent plasma levels of active principal are achieved at a lower dose, with less inter-subject variability and a reduced food effect. The new suprabioavailable tablet may, therefore, be a more efficient and better tolerated formulation.

  11. Android Tablet Application Development For Dummies

    CERN Document Server

    Felker, Donn

    2011-01-01

    Get up to speed on the hottest opportunity in the application development arena App development for tablets is a booming business. Android tablets, including the popular Motorola Xoom, are gaining market share at breakneck speed, and this book can have even novice programmers creating great Android apps specifically for tablets quickly and easily. A little Java knowledge is helpful but not essential to get started creating apps. Android expert Donn Felker helps you get the Android environment up and running, use XML to create application menus, create an icon for your app, and submit your app

  12. Highly anisotropic conductivity of tablets pressed from polyaniline-montmorillonite nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Tokarský, Jonáš, E-mail: jonas.tokarsky@vsb.cz [Nanotechnology centre, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava—Poruba (Czech Republic); IT4Innovations Centre of Excellence, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava—Poruba (Czech Republic); Kulhánková, Lenka [Faculty of Metallurgy and Materials Engineering, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava—Poruba (Czech Republic); Neuwirthová, Lucie; Mamulová Kutláková, Kateřina [Nanotechnology centre, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava—Poruba (Czech Republic); Vallová, Silvie [Faculty of Metallurgy and Materials Engineering, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava—Poruba (Czech Republic); Stýskala, Vítězslav [Faculty of Electrical Engineering and Computer Science, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava—Poruba (Czech Republic); Čapková, Pavla [Faculty of Science, University of J.E. Purkyně, České mládeže 8, 400 96 Ústí nad Labem (Czech Republic)

    2016-03-15

    Highlights: • Montmorillonite (MMT) can be intercalated with polyaniline (PANI) chains. • Tablets pressed from PANI/MMT exhibit high anisotropy in electrical conductivity. • Pressure 28MPa is sufficient to reach the anisotropy. • Tablets pressed from pure PANI also exhibit anisotropy in electrical conductivity. - Abstract: Polyaniline-montmorillonite nanocomposite was prepared from anilinium sulfate (precursor) and ammonium peroxodisulfate (oxidizing agent) using simple one-step method. The resulting nanocomposite obtained in powder form has been pressed into tablets using various compression pressures (28–400 MPa). Electrical conductivities of tablets in two perpendicular directions, i.e. direction parallel with the main surface of tablet (σ=) and in orthogonal direction (σ⊥), and corresponding anisotropy factors (i.e., the ratio σ=/σ⊥) have been studied in dependence on compression pressure used during the preparation. Polyaniline-montmorillonite nanocomposite was characterized using X-ray diffraction analysis, raman spectroscopy, transmission electron microscopy, thermogravimetric analysis and molecular modeling which led to the understanding of the internal structure. Measurement of hardness performed on pressed tablets has been also involved. Taking into account the highest value of anisotropy factor reached (σ=/σ⊥ = 490), present study shows a chance to design conductors with nearly two-dimensional conductivity.

  13. Application of quality by design concepts in the development of fluidized bed granulation and tableting processes.

    Science.gov (United States)

    Djuris, Jelena; Medarevic, Djordje; Krstic, Marko; Djuric, Zorica; Ibric, Svetlana

    2013-06-01

    This study illustrates the application of experimental design and multivariate data analysis in defining design space for granulation and tableting processes. According to the quality by design concepts, critical quality attributes (CQAs) of granules and tablets, as well as critical parameters of granulation and tableting processes, were identified and evaluated. Acetaminophen was used as the model drug, and one of the study aims was to investigate the possibility of the development of immediate- or extended-release acetaminophen tablets. Granulation experiments were performed in the fluid bed processor using polyethylene oxide polymer as a binder in the direct granulation method. Tablets were compressed in the laboratory excenter tablet press. The first set of experiments was organized according to Plackett-Burman design, followed by the full factorial experimental design. Principal component analysis and partial least squares regression were applied as the multivariate analysis techniques. By using these different methods, CQAs and process parameters were identified and quantified. Furthermore, an in-line method was developed to monitor the temperature during the fluidized bed granulation process, to foresee possible defects in granules CQAs. Various control strategies that are based on the process understanding and assure desired quality attributes of the product are proposed.

  14. INDUSTRIAL PROCESS VALIDATION OF TABLET DOSAGE FORM: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Gupta Surbhi

    2012-03-01

    Full Text Available In pharmaceutical organizations, validation is a fundamental segment that supports a company commitment to quality assurance. Validation is a tool of quality assurance which provides confirmation of the quality in equipment systems, manufacturing processes, software and testing methods. Validation assures that products with pre-determined quality characteristics and attributes can be reproduced consistently/reproducibly within the established limits of the manufacturing process operation at the manufacturing site. Validation of the individual steps of the manufacturing processes is called the process validation. Different dosage forms have different validation protocols. Here this article concentrates on the process validation of tablet dosage form, protocol preparation and regulatory basis for process validation in industry. It gives in detail the validation of each step of the manufacturing process of tablets through wet granulation.

  15. Effect of polymers on in-vitro performance of eplerenone sustained release matrix tablets

    Directory of Open Access Journals (Sweden)

    Sunil Reddy

    2012-01-01

    Full Text Available Objectives: The intention of the present study was to design and assess oral sustained drug delivery systems for Eplerenone, using Cellulose and natural polymers as release modifiers in the form of matrix tablets. Material and methods: Matrix tablets containing cellulose polymers like HPMC K4M, HPMC K15M, NaCMC and natural polymers like Guar Gum, Xanthan Gum, and Karaya Gum were prepared by wet granulation technique using PVP K60 as a tablet binder. Results: The optimized formulation (F1 contains 1: 0.70 ratio (D: HPMC K4M and (F4 contains 1:1 ratio (D: Guar gum respectively. The in-vitro release kinetic studies of prepared matrix tablets with both the polymers were studied. The kinetic treatment illustrate that the optimized formulation (F1 and F4 followed zero order kinetics with release exponent (n 0.87. Drug content in the tablets and amount of drug released were estimated by reported HPLC method. The FT-IR and DSC studies did not show any interaction of drug with the excipients used in the formulation. Conclusion: The results clearly indicated that Eplerenone could be successfully prepared using an appropriate ratio of cellulose polymers like HPMC K4M, and natural gums like Guar gum in the form of matrix tablets

  16. Development and evaluation of buccoadhesive tablet for selegiline hydrochloride based on thiolated polycarbophil.

    Science.gov (United States)

    Wasnik, Mangesh N; Godse, Rutika D; Nair, Hema A

    2014-05-01

    Selegiline hydrochloride (SHCl), a monoamine oxidase B inhibitor, is used as an adjunct in the therapy of Parkinson's disease. This study is concerned with the preparation and evaluation of mucoadhesive buccal tablet for controlled systemic delivery of SHCl. Buccal absorption of selegiline can bypass its first-pass metabolism and improve bioavailability accompanied by greatly reduced metabolite formation, which is potentially of enhanced therapeutic value in patients with Parkinson's disease. Polycarbophil-cysteine (PCP-cys) conjugate, which is a thiolated derivative of the mucoadhesive polymer polycarbophil, was synthesized by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride-mediated amide bond coupling. Tablets of SHCl based on native and thiolated polycarbophil were prepared. The prepared tablets were evaluated for drug content, swelling behavior, mucoadhesive strength, in vitro drug release, ex vivo permeation and in vitro cytotoxicity. PCP-cys tablets showed enhanced mucoadhesion and retarded drug release compared to polycarbophil tablets. Permeation data of SHCl from matrices prepared using the PCP-cys polymer revealed a significantly higher value of apparent permeability in comparison to polycarbophil, which supported the information in literature that thiolation imparts permeation enhancing properties to mucoadhesive polymers. In vitro cytotoxicity studies on PCP-cys using L-929 mouse fibroblast cell line indicated that conjugation with cysteine does not impart any apparent toxicity to polycarbophil. The results from the study indicate that the buccal delivery of SHCl using thiolated polycarbophil tablet could provide a way for improved therapy of Parkinson's disease.

  17. ACECLOFENAC FLOATING TABLETS - A PROMISING SUSTAINED RELEASE DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Ambati Brahma reddy

    2011-06-01

    Full Text Available The purpose of the present study was to develop an optimized gastric floating drug delivery system (GFDDS containing Aceclofenac as a model drug by using various proportion of polymers such as HPMC E5M and Eudragit RS 100. This was employed to enhance the bioavailability and therapeutic efficacy of the drug. The sustained release formulations of aceclofenac using hydrophobic and hydrophilic polymers were prepared by direct compression method. Optimization of formulation was done by studying effect of drug to polymer ratio on drug release. FT- IR studies indicated absence of any interaction between aceclofenac, polymer (Eudragit RS 100, HPMCE5M and excipients. Five formulations were prepared and formulation A5 possessed good floating property with total floating time between 8-10 hours. The tablets were also evaluated for its hardness, friability and other In- vitro evaluation tests. All parameters complied with IP limits. Results of this study indicated that the combinations of hydrophilic polymers with hydrophobic polymers are suitable to optimize sustained release formulation of aceclofenac.

  18. Microstructure of Tablet-Pharmaceutical Significance, Assessment, and Engineering.

    Science.gov (United States)

    Sun, Changquan Calvin

    2017-05-01

    To summarize the microstructure - property relationship of pharmaceutical tablets and approaches to improve tablet properties through tablet microstructure engineering. The main topics reviewed here include: 1) influence of material properties and manufacturing process parameters on the evolution of tablet microstructure; 2) impact of tablet structure on tablet properties; 3) assessment of tablet microstructure; 4) development and engineering of tablet microstructure. Microstructure plays a decisive role on important pharmaceutical properties of a tablet, such as disintegration, drug release, and mechanical strength. Useful information on mechanical properties of a powder can be obtained from analyzing tablet porosity-pressure data. When helium pycnometry fails to accurately measure true density of a water-containing powder, non-linear regression of tablet density-pressure data is a useful alternative method. A component that is more uniformly distributed in a tablet generally exerts more influence on the overall tablet properties. During formulation development, it is highly recommended to examine the relationship between any property of interest and tablet porosity when possible. Tablet microstructure can be engineered by judicious selection of formulation composition, including the use of the optimum solid form of the drug and appropriate type and amount of excipients, and controlling manufacturing process.

  19. The Control System Modeling Language

    CERN Document Server

    Zagar, K; Sekoranja, M; Tkacik, G; Vodovnik, A; Zagar, Klemen; Plesko, Mark; Sekoranja, Matej; Tkacik, Gasper; Vodovnik, Anze

    2001-01-01

    The well-known Unified Modeling Language (UML) describes software entities, such as interfaces, classes, operations and attributes, as well as relationships among them, e.g. inheritance, containment and dependency. The power of UML lies in Computer Aided Software Engineering (CASE) tools such as Rational Rose, which are also capable of generating software structures from visual object definitions and relations. UML also allows add-ons that define specific structures and patterns in order to steer and automate the design process. We have developed an add-on called Control System Modeling Language (CSML). It introduces entities and relationships that we know from control systems, such as "property" representing a single controllable point/channel, or an "event" specifying that a device is capable of notifying its clients through events. Entities can also possess CSML-specific characteristics, such as physical units and valid ranges for input parameters. CSML is independent of any specific language or technology...

  20. Contextual Modelling of Collaboration System

    Directory of Open Access Journals (Sweden)

    Wafaa DACHRY

    2012-03-01

    Full Text Available Faced with new environmental constraints, firms decide to collaborate in collective entities and adopt new patterns of behavior. So, this firms’ collaboration becomes an unavoidable approach. Indeed, our aim interest in our study is to propose a collaborative information system for supply chain. Our proposed platform ensures cooperation and information sharing between partners in real time. In fact, several questions have to be asked: What is the information nature may be shared between partners? What processes are implemented between actors? What functional services are supported by the platform? In order to answer these questions, we present, in this article, our methodological approach of modelling, called CMCS (Contextual Modelling of Collaborative System

  1. Dissolution development of valdecoxib tablets

    Directory of Open Access Journals (Sweden)

    Subramanian G

    2006-01-01

    Full Text Available Valdecoxib is a nonsteroidal antiinflammatory drug, and it is listed in class 2 of biopharmaceutic classification of drugs. Valdecoxib is a poorly water-soluble and highly permeable drug. In the present study a new dissolution medium was developed, as there is no official dissolution medium available in the literature. The composition of the dissolution medium was selected on the basis of solubility data at 37°. Solubility data revealed that addition of surfactant may be suitable as dissolution medium. The concentration of 0.6% w/v sodium lauryl sulphate in water could be a suitable dissolution medium. The discriminating power of the selected dissolution medium (0.6% sodium lauryl sulphate in water relative to the other dissolution mediums was evaluated. The selected dissolution medium was used for the evaluation of valdecoxib tablets.

  2. Stochastic Models of Polymer Systems

    Science.gov (United States)

    2016-01-01

    field limit of a dynamical model for polymer systems, Science China Mathematics , (11 2012): 0. doi: TOTAL: 1 Number of Non Peer-Reviewed Conference...4.0 (4.0 max scale): Number of graduating undergraduates funded by a DoD funded Center of Excellence grant for Education , Research and Engineering...undergraduates funded by your agreement who graduated during this period and will receive scholarships or fellowships for further studies in science

  3. Model reduction of parametrized systems

    CERN Document Server

    Ohlberger, Mario; Patera, Anthony; Rozza, Gianluigi; Urban, Karsten

    2017-01-01

    The special volume offers a global guide to new concepts and approaches concerning the following topics: reduced basis methods, proper orthogonal decomposition, proper generalized decomposition, approximation theory related to model reduction, learning theory and compressed sensing, stochastic and high-dimensional problems, system-theoretic methods, nonlinear model reduction, reduction of coupled problems/multiphysics, optimization and optimal control, state estimation and control, reduced order models and domain decomposition methods, Krylov-subspace and interpolatory methods, and applications to real industrial and complex problems. The book represents the state of the art in the development of reduced order methods. It contains contributions from internationally respected experts, guaranteeing a wide range of expertise and topics. Further, it reflects an important effor t, carried out over the last 12 years, to build a growing research community in this field. Though not a textbook, some of the chapters ca...

  4. Computational models of complex systems

    CERN Document Server

    Dabbaghian, Vahid

    2014-01-01

    Computational and mathematical models provide us with the opportunities to investigate the complexities of real world problems. They allow us to apply our best analytical methods to define problems in a clearly mathematical manner and exhaustively test our solutions before committing expensive resources. This is made possible by assuming parameter(s) in a bounded environment, allowing for controllable experimentation, not always possible in live scenarios. For example, simulation of computational models allows the testing of theories in a manner that is both fundamentally deductive and experimental in nature. The main ingredients for such research ideas come from multiple disciplines and the importance of interdisciplinary research is well recognized by the scientific community. This book provides a window to the novel endeavours of the research communities to present their works by highlighting the value of computational modelling as a research tool when investigating complex systems. We hope that the reader...

  5. Formation of single-crystalline aragonite tablets/films via an amorphous precursor.

    Science.gov (United States)

    Amos, Fairland F; Sharbaugh, Denise M; Talham, Daniel R; Gower, Laurie B; Fricke, Marc; Volkmer, Dirk

    2007-02-13

    Thin tablets and films of calcium carbonate have been grown at the air-water interface via an amorphous precursor route using soluble process-directing agents and a Langmuir monolayer based on resorcarene. By using appropriate concentrations of poly(acrylic acid-sodium salt) in combination with Mg2+ ion, an initially amorphous film is deposited on the monolayer template, which subsequently crystallizes into a mosaic film composed of a mixture of single-crystalline and spherulitic patches of calcite and aragonite. Of particular importance is the synthesis of single-crystalline "tablets" of aragonite (approximately 600 nm thick), because this phase generally forms needle-like polycrystalline aggregates when grown in vitro. To our knowledge, a tabular single-crystalline morphology of aragonite has only been observed in the nacreous layer of mollusk shells. Therefore, this in vitro system may serve as a useful model for examining mechanistic issues pertinent to biomineralization, such as the influence of organic templates on nucleation from an amorphous phase.

  6. Measurements of the Diameter and Velocity Distributions of Atomized Tablet-Coating Solutions for Pharmaceutical Applications

    Science.gov (United States)

    Osterday, Kathryn; Aliseda, Alberto; Lasheras, Juan

    2009-11-01

    The atomization of colloidal suspensions is of particular interest to the manufacturing of tablets and pills used as drug delivery systems by the pharmaceutical industry. At various stages in the manufacturing process, the tablets are coated with a spray of droplets produced by co-axial atomizers. The mechanisms of droplet size and spray formation in these types of atomizers are dominated by Kelvin-Helmholtz and Raleigh-Taylor instabilities for both low[1] and high[2] Ohnesorge numbers. We present detailed phase Doppler measurements of the Sauter Mean Diameter of the droplets produced by co-axial spray atomizers using water-based colloidal suspensions with solid concentrations ranging from fifteen to twenty percent and acetone-based colloidal suspensions with solid concentrations ranging from five to ten percent. Our results compare favorably with predictions by Aliseda's model. This suggests that the final size distribution is mainly determined by the instabilities caused by the sudden acceleration of the liquid interface. [1]Varga, C. M., et al. (2003) J. Fluid Mech. 497:405-434 [2]Aliseda, A. et al. (2008). J. Int. J. Multiphase Flow, 34(2), 161-175.

  7. Tablets for Learning in Higher Education

    DEFF Research Database (Denmark)

    Godsk, Mikkel

    Based on a small-scale literature review this paper identifies the top 10 affordances of post PC tablets (sometimes referred to as ‘tablet computers’) for higher education in settings where the technology is used for learning. The review shows that the predominant affordances of the technology......, the concepts of tabletcasts and tabletcasting are introduced as one possible framing for future research on tablets as an educational technology....... are related to its ability to support engaging, inclusive, and/or collaborative learning, to provide flexibility in place, and to include multimedia and interactive content in teaching practice. However, performing the review also revealed that the notion of tablets for learning is equivocal. As a consequence...

  8. Identification and Modelling of Linear Dynamic Systems

    Directory of Open Access Journals (Sweden)

    Stanislav Kocur

    2006-01-01

    Full Text Available System identification and modelling are very important parts of system control theory. System control is only as good as good is created model of system. So this article deals with identification and modelling problems. There are simple classification and evolution of identification methods, and then the modelling problem is described. Rest of paper is devoted to two most known and used models of linear dynamic systems.

  9. In-line monitoring of compaction properties on a rotary tablet press during tablet manufacturing of hot-melt extruded amorphous solid dispersions.

    Science.gov (United States)

    Grymonpré, W; Verstraete, G; Van Bockstal, P J; Van Renterghem, J; Rombouts, P; De Beer, T; Remon, J P; Vervaet, C

    2017-01-30

    As the number of applications for polymers in pharmaceutical development is increasing, there is need for fundamental understanding on how such compounds behave during tableting. This research is focussed on the tableting behaviour of amorphous polymers, their solid dispersions and the impact of hot-melt extrusion on the compaction properties of these materials. Soluplus, Kollidon VA 64 and Eudragit EPO were selected as amorphous polymers since these are widely studied carriers for solid dispersions, while Celecoxib was chosen as BCS class II model drug. Neat polymers and physical mixtures (up to 35% drug load) were processed by hot-melt extrusion (HME), milled and sieved to obtain powders with comparable particle sizes as the neat polymer. A novel approach was used for in-line analysis of the compaction properties on a rotary tablet press (Modul P, GEA) using complementary sensors and software (CDAAS, GEA). By combining 'in-die' and 'out-of-die' techniques, it was possible to investigate in a comprehensive way the impact of HME on the tableting behaviour of amorphous polymers and their formulations. The formation of stable glassy solutions altered the formulations towards more fragmentary behaviour under compression which was beneficial for the tabletability. Principal component analysis (PCA) was applied to summarize the behaviour during compaction of the formulations, enabling the selection of Soluplus and Kollidon VA 64 as the most favourable polymers for compaction of glassy solutions.

  10. Electronic acquisition of OSCE performance using tablets

    Directory of Open Access Journals (Sweden)

    Hochlehnert, Achim

    2015-10-01

    Full Text Available Background: Objective Structured Clinical Examinations (OSCEs often involve a considerable amount of resources in terms of materials and organization since the scores are often recorded on paper. Computer-assisted administration is an alternative with which the need for material resources can be reduced. In particular, the use of tablets seems sensible because these are easy to transport and flexible to use.Aim: User acceptance concerning the use of tablets during OSCEs has not yet been extensively investigated. The aim of this study was to evaluate tablet-based OSCEs from the perspective of the user (examiner and the student examinee.Method: For two OSCEs in Internal Medicine at the University of Heidelberg, user acceptance was analyzed regarding tablet-based administration (satisfaction with functionality and the subjective amount of effort as perceived by the examiners. Standardized questionnaires and semi-standardized interviews were conducted (complete survey of all participating examiners. In addition, for one OSCE, the subjective evaluation of this mode of assessment was gathered from a random sample of participating students in semi-standardized interviews.Results: Overall, the examiners were very satisfied with using tablets during the assessment. The subjective amount of effort to use the tablet was found on average to be “hardly difficult”. The examiners identified the advantages of this mode of administration as being in particular the ease of use and low rate of error. During the interviews of the examinees, acceptance for the use of tablets during the assessment was also detected.Discussion: Overall, it was found that the use of tablets during OSCEs was well accepted by both examiners and examinees. We expect that this mode of assessment also offers advantages regarding assessment documentation, use of resources, and rate of error in comparison with paper-based assessments; all of these aspects should be followed up on in

  11. Tablets with thyme (Thymus Vulgaris L extracts

    Directory of Open Access Journals (Sweden)

    Zeković Zoran P.

    2002-01-01

    Full Text Available The strongly antiseptic and antifungal activities of thyme is mainly due to the presence of phenolic compounds, thymol and carvacrol. Thyme extracts essential oil, extract obtained using 70% ethanol and extract obtained by supercritical fluid extraction (SFE using carbon dioxide, were incorporated in the most useful form of pharmaceutical products - tablets. The work is concerned with the characterisation of the obtained tablets containing thyme extracts.

  12. MOUTH DISSOLVING TABLETS: A FUTURE COMPACTION

    Directory of Open Access Journals (Sweden)

    Srivastava Saurabh

    2012-08-01

    Full Text Available An orally disintegrating tablet or mouth dissolving tablet (MDT is a drug dosage form available for a limited amount of over-the-counter (OTC and prescription medications. MDTs differ from traditional tablets in that they are designed to be dissolved on the tongue rather than swallowed whole. A variety of pharmaceutical research has been conducted to develop new dosage forms. Among the dosage forms developed to facilitate ease of medication, the mouth dissolving tablet (MDT is one of the most widely employed commercial products. As our society is becoming increasingly aged, the development of mouth dissolving tablets have been formulated for pediatric, geriatric, and bedridden patients and for active patients who are busy and travelling and may not have access to water. Such formulations provide an opportunity for product line extension in the many elderly persons will have difficulties in taking conventional oral dosage forms (viz., solutions, suspensions, tablets, and capsules because of hand tremors and dysphagia. Oral delivery is currently the gold standard in the pharmaceutical industry where it is regarded as the safest, most convenient and most economical method of drug delivery having the highest patient compliance. Recent development in fast disintegrating technology mainly works to improve the disintegration quality of these delicate dosage forms without affecting their integrity. This article focuses on the patented technologies available and the advances made so far in the field of fabrication of mouth dissolving tablets. Apart from the conventional methods of fabrication, this review also provides the detailed concept of some unique technologies like freeze drying, direct compression, spray drying, tablet molding, sublimation, fast dissolving films cotton candy process, along with their advantages and limitations.

  13. Tablets Helping Elderly and Disabled People

    OpenAIRE

    Castro, Mercedes; Ruiz-Mezcua, Belén; Sánchez-Pena, José Manuel; García-Crespo, Ángel; Iglesias, Ana; Pajares, José Luis

    2012-01-01

    Proceedings of: Ambient Assisted Living Joint Programme Forum 2011 (AAL JP Forum 2011), Lecce (Italy), September 26-28, 2011 The article introduces the basics by which tablets are considered as appropriate tools for integration and promotion of the elderly in the digital world. To prove this, the paper presents three research projects carried out by CESyA that integrate Automatic Speech Recognition (ASR), Voice Synthesis, subtitling, audiodescription or audio navigation tools into tablets ...

  14. Evaluation of tablet PC as a tool for teaching tooth brushing to children.

    Science.gov (United States)

    Salama, F; Abobakr, I; Al-Khodair, N; Al-Wakeel, M

    2016-12-01

    This study evaluated the effect of a single time tooth brushing instruction using video on a tablet PC (Apple iPad) compared to operator presentation using jaw model for plaque removal. This cross-sectional study included a convenience sample of 100 children divided into two groups. For Group 1 brushing was demonstrated to the child by the operator with the use of a jaw model. This demonstration was videotaped for subsequent use in Group 2 using a tablet PC (Apple iPad). Plaque index was recorded before and after demonstration of the assigned method of teaching tooth brushing. The results showed a significant difference using the two methods. The difference between the mean plaque index values with the jaw model and tablet PC at baseline and after tooth brushing represented 17.27% (50% improvement) and 11.56% (34% improvement) respectively. Boys showed a 18.3%. higher improvement in tooth brushing compared to girls. Seventy-five percent of the children reported using tablet computers in their daily life. CONCLUSION Teaching children by using a jaw model was more effective in improving plaque index score than using video on tablet PC by 16%. Both methods of tooth brushing teaching were fully accepted by all children.

  15. Formulation and evaluation of floating matrix tablets of diltiazem hydrochloride

    Directory of Open Access Journals (Sweden)

    Vinay D Gaikwad

    2012-01-01

    Full Text Available This study was performed to design floating tablets of diltiazem as a model drug for prolongation of gastric residence time. A simple visible spectrophotometric method was employed for the estimation of diltiazem at 236 nm and Beer′s law is obeyed in the concentration range of 2-20 mg/ml. Preformulation studies were carried out to optimize the ratios required for various grades of HPMC-SCMC and HPMC- Carbopol P934. Total 10 formulations (five each were prepared using HPMC (K4M. The prepared floating tablets were evaluated for hardness, weight variation, thickness, friability, drug content uniformity, buoyancy lag time, total floating time, water uptake (swelling index, and in vitro dissolution studies. SEM and stability studies were carried out only for best release formulations (A1 and B1. Among the five formulations with HPMC K4M and A1-A4 showed drug release ranging from 99.89 to 77.52%. Similarly five formulations with HPMC K4M and Carbopol P934 (B1-B4 showed drug release ranging from 97.9 to 80.35% in 0.1 N HCl dissolution medium. Formulations A1 and B1 gave maximum drug release upto 100% within 12 hrs. SEM for A1 and B1 formulations revealed that surface was smooth upto 4 hrs after that swelling and porosity of tablet increased indicating the diffusion and erosion mechanism of release.

  16. FORMULATION AND EVALUATION OF EXTENDED RELEASE TABLETS OF TRAMADOL HYDROCHLORIDE

    Directory of Open Access Journals (Sweden)

    Chilvalvar Sapnil

    2013-10-01

    Full Text Available The objective of this research work was to develop extended release tablets (Twice in a day of Tramadol Hydrochloride using different Hydrophilic polymers like HPMC K15M, HPMC K4M, Metalose 60SH50, Carbopol 971P, Sodium alginate, Xanthan gum by direct compression method. Various amounts of polymers was used in the twenty four proposed formulations (F1 to F24 for the study of release rate retardant effect at 10 %, 15 %, 20 %, 25 % of total weight of tablet matrix respectively. Then the tablets were evaluated in terms of their physical parameters (weight variation, hardness, friability and thickness, drug content and in-vitro release studies. All the formulations showed compliance with pharmacopoeial standards. The in-vitro dissolution study were conducted using USP dissolution apparatus type-II (paddle method in 900 ml 0.1 N HCl for first 2 h and remaining 10 h performed in 6.8 pH phosphate buffer at 100 rpm for a total period of 12 h. Based on the dissolution data comparison with innovator product, formulation F14 was found as the best formulation. The drug release of formulation F14 followed First Order kinetic model and the mechanism was found to be non-Fickian/anomalous according to Korsmeyer-Peppas equation.

  17. Novel colon targeted drug delivery system using natural polymers

    Directory of Open Access Journals (Sweden)

    Ravi V

    2008-01-01

    Full Text Available A novel colon targeted tablet formulation was developed using pectin as carrier and diltiazem HCl and indomethacin as model drugs. The tablets were coated with inulin followed by shellac and were evaluated for average weight, hardness and coat thickness. In vitro release studies for prepared tablets were carried out for 2 h in pH 1.2 HCl buffer, 3 h in pH 7.4 phosphate buffer and 6 h in simulated colonic fluid. The drug release from the coated systems was monitored using UV/Vis spectroscopy. In vitro studies revealed that the tablets coated with inulin and shellac have limited the drug release in stomach and small intestinal environment and released maximum amount of drug in the colonic environment. The study revealed that polysaccharides as carriers and inulin and shellac as a coating material can be used effectively for colon targeting of both water soluble and insoluble drugs.

  18. Evaluation of Three Chitin Metal Silicate Co-Precipitates as a Potential Multifunctional Single Excipient in Tablet Formulations

    Directory of Open Access Journals (Sweden)

    Rana Al-Shaikh Hamid

    2010-05-01

    Full Text Available The performance of the novel chitin metal silicate (CMS co-precipitates as a single multifunctional excipient in tablet formulation using direct compression and wet granulation methods is evaluated. The neutral, acidic, and basic drugs Spironolactone (SPL, ibuprofen (IBU and metronidazole (MET, respectively, were used as model drugs. Commercial Aldactone®, Fleximex® and Dumazole® tablets containing SPL, IBU and MET, respectively, and tablets made using Avicel® 200, were used in the study for comparison purposes. Tablets of acceptable crushing strength (>40 N were obtained using CMS. The friability values for all tablets were well below the maximum 1% USP tolerance limit. CMS produced superdisintegrating tablets (disintegration time < 1 min with the three model drugs. Regarding the dissolution rate, the sequence was as follow: CMS > Fleximex® > Avicel® 200, CMS > Avicel® 200 > Dumazole® and Aldactone® > Avicel® 200 > CMS for IBU, MET and SPL, respectively. Compressional properties of formulations were analyzed using density measurements and the compression Kawakita equation as assessment parameters. On the basis of DSC results, CMS co precipitates were found to be compatible with the tested drugs. Conclusively, the CMS co-precipitates have the potential to be used as filler, binder, and superdisintegrant, all-in-one, in the design of tablets by the direct compression as well as wet granulation methods.

  19. Formulation and optimization of potassium iodide tablets.

    Science.gov (United States)

    Al-Achi, Antoine; Patel, Binit

    2015-01-01

    The use of potassium iodide (KI) as a protective agent against accidental radioactive exposure is well established. In this study, we aimed to prepare a KI tablet formulation using a direct compression method. We utilized Design of Experiment (DoE)/mixture design to define the best formulation with predetermined physical qualities as to its dissolution, hardness, assay, disintegration, and angle of repose. Based on the results from the DoE, the formulation had the following components (%w/w): Avicel 48.70%, silicon dioxide 0.27%, stearic acid (1.00%), magnesium stearate 2.45%, and dicalcium phosphate 18.69%, in addition to potassium iodide 28.89% (130 mg/tablet). This formulation was scaled-up using two tablet presses, a single-punch press and a rotary mini tablet press. The final scaled-up formulation was subjected to a variety of quality control tests, including photo-stability testing. The results indicate that potassium iodide tablets prepared by a rotary mini tablet press had good pharmaceutical characteristics and a shelf-life of 25 days when stored at room temperature protected from light.

  20. [Overview of regulatory aspects guiding tablet scoring].

    Science.gov (United States)

    Teixeira, Maíra Teles; Sá-Barreto, Lívia Cristina Lira; Silva, Dayde Lane Mendonça; Cunha-Filho, Marcílio Sergio Soares

    2016-06-01

    Tablet scoring is a controversial but common practice used to adjust doses, facilitate drug intake, or lower the cost of drug treatment, especially in children and the elderly. The risks of tablet scoring are mainly related to inaccuracies in the resulting dose and stability problems. The aim of this article is to provide an overview of worldwide guidelines regarding tablet scoring. We found that regulatory health agencies in Mercosur countries as well as other South American countries do not have published standards addressing tablet splitting. Among the surveyed health agencies, the Food and Drug Administration (FDA) in the United States is the only one to present standards, ranging from splitting instructions to regulation of the manufacturing process. The concept of functional scoring implemented by the FDA has introduced some level of guarantee as to the ability of tablets to be split. In conclusion, technical and scientific bases are still insufficient to guide health rules on this subject, making the decision on scoring, in certain situations, random and highly risky to public health. The need for more detailed regulation is vital to ensure the safety of tablet medications.

  1. Formulation and evaluation of antihelminthic polyherbal tablets

    Directory of Open Access Journals (Sweden)

    Dinesh Puri

    2011-01-01

    Full Text Available From time immemorial, man has been depending on plants as medicine. Helminthes infections are among the most common infections in man, affecting a large proportion of the world′s population. These helminthic diseases can be treated by various herbal drugs. The purpose of the present work was to formulate antihelminthic tablets. In this work, a spray dried-powder was used, which was obtained from the extract of different part of seven plants that were used in helminthic disease. The different tablets were prepared by using different types of disintegrating agents and various excipients. All parameters related to physicochemical property, trace metal and microbial examination of the spray-dried powder showed that these were within limits and could be used for the tablet formulation. The granules of the spray-dried powder were prepared by a wet granulation technique using isopropyl alcohol. The blends were evaluated for flow properties and for compressibility, which were found to be good. The tablets were prepared using a single rotatory punching machine, in which the punch size was 11 mm×8 mm, and formulated caplet-type tablets. These tablets were evaluated for the colour, odor, thickness and diameter, with visual inspection for any defects, weight variation, hardness, friability and in vitro disintegration time.

  2. FORMULATION AND EVALUATION OF CONTROLLED POROSITY OSMOTIC TABLETS OF LORNOXICAM

    Directory of Open Access Journals (Sweden)

    A. Uma Maheswari*, K. Elango, Daisy Chellakumari, K. Saravanan and Anglina Jeniffer Samy

    2012-06-01

    Full Text Available The aim of the present study is to formulate and evaluate controlled release formulation of lornoxicam based on osmotic technology. Lornoxicam, a potent non-steroidal anti-inflammatory drug (NSAID with shorter half life, makes the development of sustained release (SR dosage forms extremely advantageous. However, due to its weak acidic nature, its release from SR delivery system is limited to the lower GIT which consequently leads to a delayed onset of its analgesic action. Basic pH modifier tromethamine and wicking agent SLS were incorporated into the core tablet to create basic environmental pH inside the tablets, which provide complete drug release that starts in the stomach to rapidly alleviate the painful symptoms and continue in the intestine to maintain protracted analgesic effect. The effect of different formulation variables namely level of osmogen (mannitol in the core tablet and level of pore former (sorbitol in the coating membrane on in-vitro release was studied. Lornoxicam release from controlled porosity osmotic pump was directly proportional to the pore former (sorbitol and level of osmogen (mannitol. Drug release from the developed formulations was independent of pH and agitational intensity and was dependent on osmotic pressure of the release media. Results of SEM studies showed the formation of pores in the membrane from where the drug release occurred. The optimized formulation was found to release the drug in zero order and found to be stable upon stability studies.

  3. Novel use of smart tablet computer for ophthalmology

    Directory of Open Access Journals (Sweden)

    Zhao-Tian Zhang

    2015-01-01

    Full Text Available AIM:To identify and categorize ophthalmology-relevant apps for the iPad tablet computer as a source for ophthalmic practices on the Apple's App Store.METHODS: The Apple's App Store was searched for ophthalmology-relevant apps from January 2013 to August 2013. Eligible apps were identified and downloaded into the iPad tablet computers, and then categorized according to the apps' initial contents and our using experiences. Methods about how to use the iPad's built-in functions of instant video call(FaceTime®and automatic data storage technology(iCloud®were also described together with the apps. Other operating systems of Microsoft's Window Phone and Google's Android were also searched for ophthalmology-relevant apps.RESULTS: The keywords for searching on the Apple's App Store were “ophthalmology” and “eye”. And we could found 111 eligible apps with the former keyword, and 452 ones with the latter one. The integrated uses of the iPad tablet computer were then categorized into five aspects. Based on our clinical practice, we finally summarized the advantages and disadvantages of the iPad tablet computer for ophthalmic practices. However, ophthalmology-relevant apps were found to be very limited in number on the other two platforms.CONCLUSION: The integrated use of self built-in apps and third-party apps can facilitate our clinical work in examination, telemedicine, reference, disease education and literature searching. More studies are needed to verify its validation and reliability in the professional fields, especially eye examinations.

  4. ISSM: Ice Sheet System Model

    Science.gov (United States)

    Larour, Eric; Schiermeier, John E.; Seroussi, Helene; Morlinghem, Mathieu

    2013-01-01

    In order to have the capability to use satellite data from its own missions to inform future sea-level rise projections, JPL needed a full-fledged ice-sheet/iceshelf flow model, capable of modeling the mass balance of Antarctica and Greenland into the near future. ISSM was developed with such a goal in mind, as a massively parallelized, multi-purpose finite-element framework dedicated to ice-sheet modeling. ISSM features unstructured meshes (Tria in 2D, and Penta in 3D) along with corresponding finite elements for both types of meshes. Each finite element can carry out diagnostic, prognostic, transient, thermal 3D, surface, and bed slope simulations. Anisotropic meshing enables adaptation of meshes to a certain metric, and the 2D Shelfy-Stream, 3D Blatter/Pattyn, and 3D Full-Stokes formulations capture the bulk of the ice-flow physics. These elements can be coupled together, based on the Arlequin method, so that on a large scale model such as Antarctica, each type of finite element is used in the most efficient manner. For each finite element referenced above, ISSM implements an adjoint. This adjoint can be used to carry out model inversions of unknown model parameters, typically ice rheology and basal drag at the ice/bedrock interface, using a metric such as the observed InSAR surface velocity. This data assimilation capability is crucial to allow spinning up of ice flow models using available satellite data. ISSM relies on the PETSc library for its vectors, matrices, and solvers. This allows ISSM to run efficiently on any parallel platform, whether shared or distrib- ISSM: Ice Sheet System Model NASA's Jet Propulsion Laboratory, Pasadena, California uted. It can run on the largest clusters, and is fully scalable. This allows ISSM to tackle models the size of continents. ISSM is embedded into MATLAB and Python, both open scientific platforms. This improves its outreach within the science community. It is entirely written in C/C++, which gives it flexibility in its

  5. Integrated Modeling for Flood Hazard Mapping Using Watershed Modeling System

    National Research Council Canada - National Science Library

    Seyedeh S. Sadrolashrafi; Thamer A. Mohamed; Ahmad R.B. Mahmud; Majid K. Kholghi; Amir Samadi

    2008-01-01

    ...) with the Watershed Modeling System (WMS) for flood modeling is developed. It also interconnects the terrain models and the GIS software, with commercial standard hydrological and hydraulic models, including HEC-1, HEC-RAS, etc...

  6. Evaluation of Certain Pharmaceutical Quality Attributes of Lisinopril Split Tablets

    Directory of Open Access Journals (Sweden)

    Khairi M. S. Fahelelbom

    2016-10-01

    Full Text Available Tablet splitting is an accepted practice for the administration of drugs for a variety of reasons, including dose adjustment, ease of swallowing and cost savings. The purpose of this study was to evaluate the physical properties of lisinopril tablets as a result of splitting the tablets either by hand or with a splitting device. The impact of the splitting technique of lisinopril (Zestril® tablets, 20 mg on certain physical parameters such as weight variation, friability, disintegration, dissolution and drug content were studied. Splitting the tablets either by hand or with a splitter resulted in a minute but statistically significant average weight loss of <0.25% of the tablet to the surrounding environment. The variability in the weight of the hand-split tablet halves was more pronounced (37 out of 40 tablet halves varied by more than 10% from the mean weight than when using the tablet splitter (3 out of 40 tablet halves. The dissolution and drug content of the hand-split tablets were therefore affected because of weight differences. However, the pharmacopoeia requirements for friability and disintegration time were met. Hand splitting of tablets can result in an inaccurate dose and may present clinical safety issues, especially for drugs with a narrow therapeutic window in which large fluctuations in drug concentrations are undesirable. It is recommended to use tablets with the exact desired dose, but if this is not an option, then a tablet splitter could be used.

  7. Network models in anatomical systems.

    Science.gov (United States)

    Esteve-Altava, Borja; Marugán-Lobón, Jesús; Botella, Héctor; Rasskin-Gutman, Diego

    2011-01-01

    Network theory has been extensively used to model the underlying structure of biological processes. From genetics to ecology, network thinking is changing our understanding of complex systems, specifically how their internal structure determines their overall behavior. Concepts such as hubs, scale-free or small-world networks, common in the complexity literature, are now used more and more in sociology, neurosciences, as well as other anthropological fields. Even though the use of network models is nowadays so widely applied, few attempts have been carried out to enrich our understanding in the classical morphological sciences such as in comparative anatomy or physical anthropology. The purpose of this article is to introduce the usage of network tools in morphology; specifically by building anatomical networks, dealing with the most common analyses and problems, and interpreting their outcome.

  8. Thermodynamic modeling of complex systems

    DEFF Research Database (Denmark)

    Liang, Xiaodong

    Offshore reservoirs represent one of the major growth areas of the oil and gas industry, and environmental safety is one of the biggest challenges for the offshore exploration and production. The oil accidents in the Gulf of Mexico in 1979 and 2010 were two of the biggest disasters in history...... after an oil spill. Engineering thermodynamics could be applied in the state-of-the-art sonar products through advanced artificial technology, if the speed of sound, solubility and density of oil-seawater systems could be satisfactorily modelled. The addition of methanol or glycols into unprocessed well...

  9. Can percolation model describe the evolution of mechanical properties of compacts of binary systems?

    Science.gov (United States)

    Evesque, Pierre; Busignies, Virginie; Porion, Patrice; Leclerc, Bernard; Tchoreloff, Pierre

    2009-06-01

    In pharmaceutical field, the percolation theory is used to describe the change of tablet's properties with the relative density. It defines critical tablet densities from which the mechanical properties start to change. The exponent in the law is expected to be universal for a mechanical property and numerical values are proposed in the literature. In this work, the percolation model was applied to the tensile strength and the reduced modulus of elasticity of three compacted pharmaceutical excipients. This work showed that the exponent seems not universal and that the model must be used carefully.

  10. Models for Gaze Tracking Systems

    Directory of Open Access Journals (Sweden)

    Villanueva Arantxa

    2007-01-01

    Full Text Available One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, that is, determining the point the subject is looking at. The calibration process permits generally adjusting nonintrusive trackers based on quite different hardware and image features to the subject. The negative aspect of this simple procedure is that it permits the system to work properly but at the expense of a lack of control over the intrinsic behavior of the tracker. The objective of the presented article is to overcome this obstacle to explore more deeply the elements of a video-oculographic system, that is, eye, camera, lighting, and so forth, from a purely mathematical and geometrical point of view. The main contribution is to find out the minimum number of hardware elements and image features that are needed to determine the point the subject is looking at. A model has been constructed based on pupil contour and multiple lighting, and successfully tested with real subjects. On the other hand, theoretical aspects of video-oculographic systems have been thoroughly reviewed in order to build a theoretical basis for further studies.

  11. Models for Gaze Tracking Systems

    Directory of Open Access Journals (Sweden)

    Arantxa Villanueva

    2007-10-01

    Full Text Available One of the most confusing aspects that one meets when introducing oneself into gaze tracking technology is the wide variety, in terms of hardware equipment, of available systems that provide solutions to the same matter, that is, determining the point the subject is looking at. The calibration process permits generally adjusting nonintrusive trackers based on quite different hardware and image features to the subject. The negative aspect of this simple procedure is that it permits the system to work properly but at the expense of a lack of control over the intrinsic behavior of the tracker. The objective of the presented article is to overcome this obstacle to explore more deeply the elements of a video-oculographic system, that is, eye, camera, lighting, and so forth, from a purely mathematical and geometrical point of view. The main contribution is to find out the minimum number of hardware elements and image features that are needed to determine the point the subject is looking at. A model has been constructed based on pupil contour and multiple lighting, and successfully tested with real subjects. On the other hand, theoretical aspects of video-oculographic systems have been thoroughly reviewed in order to build a theoretical basis for further studies.

  12. Improvement of tablet coating uniformity using a quality by design approach.

    Science.gov (United States)

    Dubey, Atul; Boukouvala, Fani; Keyvan, Golshid; Hsia, Richard; Saranteas, Kostas; Brone, Dean; Misra, Tushar; Ierapetritou, Marianthi G; Muzzio, Fernando J

    2012-03-01

    A combination of analytical and statistical methods is used to improve a tablet coating process guided by quality by design (QbD) principles. A solid dosage form product was found to intermittently exhibit bad taste. A suspected cause was the variability in coating thickness which could lead to the subject tasting the active ingredient in some tablets. A number of samples were analyzed using a laser-induced breakdown spectroscopy (LIBS)-based analytical method, and it was found that the main variability component was the tablet-to-tablet variability within a lot. Hence, it was inferred that the coating process (performed in a perforated rotating pan) required optimization. A set of designed experiments along with response surface modeling and kriging method were used to arrive at an optimal set of operating conditions. Effects of the amount of coating imparted, spray rate, pan rotation speed, and spray temperature were characterized. The results were quantified in terms of the relative standard deviation of tablet-averaged LIBS score and a coating variability index which was the ratio of the standard deviation of the tablet-averaged LIBS score and the weight gain of the tablets. The data-driven models developed based on the designed experiments predicted that the minimum value of this index would be obtained for a 6% weight gain for a pan operating at the highest speed at the maximum fill level while using the lowest spraying rate and temperature from the chosen parametric space. This systematic application of the QbD-based method resulted in an enhanced process understanding and reducing the coating variability by more than half.

  13. Area Logistics System Based on System Dynamics Model

    Institute of Scientific and Technical Information of China (English)

    GUI Shouping; ZHU Qiang; LU Lifang

    2005-01-01

    At present, there are few effective ways to analyze area logistics systems. This paper uses system dynamics to analyze the area logistics system and establishes a system dynamics model for the area logistics system based on the characteristics of the area logistics system and system dynamics. Numerical simulations with the system dynamic model were used to analyze a logistic system. Analysis of the Guangzhou economy shows that the model can reflect the actual state of the system objectively and can be used to make policy and harmonize environment.

  14. Evaluation of Rapidly Disintegrating Vaginal Tablets of Tenofovir, Emtricitabine and Their Combination for HIV-1 Prevention

    Directory of Open Access Journals (Sweden)

    Meredith R. Clark

    2014-12-01

    Full Text Available Vaginal tablets are being developed as an alternative to gels as an inexpensive, discreet dosage form for the administration of microbicides. This work describes the pharmacokinetic (PK evaluation of rapidly disintegrating vaginal tablets containing tenofovir (TFV, 10 mg, emtricitabine (FTC, 10 mg, and the combination of TFV and FTC (10 mg each under in vitro and in vivo conditions, and in direct comparison to the clinical TFV 1% gel, a microbicide product in Phase III clinical testing. The PK of TFV and FTC from tablets were also evaluated in female rabbits following intravaginal administration. Direct comparison of a single dose of TFV tablets (intact or predissolved at 10 mg/mL and TFV 1% gel showed no differences in the vaginal PK of TFV between groups; however systemic bioavailability of TFV was significantly higher from the gel. When rabbits were dosed either once or daily for seven days with intact tablets of TFV, FTC, or the combination of TFV/FTC, vaginal and systemic concentrations of TFV and FTC were unaffected by co-formulation. Moreover, plasma PK parameters were similar following a single dose or seven once-daily doses. Tissue concentrations of TFV and FTC in the cranial vagina 4 h after administration ranged between 104 and 105 ng/g. Concentrations of TFV-diphospate (TFV-DP, the active metabolite were also high (over 103 ng/g or about 3000 to 6000 fmol/mg in the cranial vagina 4 h after administration and similar to those measured following administration of TFV 1% gel. These data demonstrate that rapidly disintegrating vaginal tablets may be a suitable topical microbicide dosage form providing similar vaginal TFV PK to that of TFV 1% gel. The data also support co-administration of FTC with TFV in a single vaginal tablet to create a combination microbicide in a simple and inexpensive dosage form.

  15. Enterprise Modelling supported by Manufacturing Systems Theory

    OpenAIRE

    MYKLEBUST, Odd

    2002-01-01

    There exist today a large number of enterprise models or enterprise modelling approaches. In a study of standards and project developed models there are two approaches: CIMOSA “The Open Systems Architecture for CIM” and GERAM, “Generalised Enterprise Reference Architecture”, which show a system orientation that can be further followed as interesting research topics for a system theory oriented approach for enterprise models. In the selection of system theories, manufacturing system theory...

  16. Modeling learning technology systems as business systems

    NARCIS (Netherlands)

    Avgeriou, Paris; Retalis, Symeon; Papaspyrou, Nikolaos

    2003-01-01

    The design of Learning Technology Systems, and the Software Systems that support them, is largely conducted on an intuitive, ad hoc basis, thus resulting in inefficient systems that defectively support the learning process. There is now justifiable, increasing effort in formalizing the engineering o

  17. Modeling learning technology systems as business systems

    NARCIS (Netherlands)

    Avgeriou, Paris; Retalis, Symeon; Papaspyrou, Nikolaos

    2003-01-01

    The design of Learning Technology Systems, and the Software Systems that support them, is largely conducted on an intuitive, ad hoc basis, thus resulting in inefficient systems that defectively support the learning process. There is now justifiable, increasing effort in formalizing the engineering

  18. Nonlinear System Identification and Behavioral Modeling

    CERN Document Server

    Huq, Kazi Mohammed Saidul; Kabir, A F M Sultanul

    2010-01-01

    The problem of determining a mathematical model for an unknown system by observing its input-output data pair is generally referred to as system identification. A behavioral model reproduces the required behavior of the original analyzed system, such as there is a one-to-one correspondence between the behavior of the original system and the simulated system. This paper presents nonlinear system identification and behavioral modeling using a work assignment.

  19. A View of Earth System Model Development

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tianjun; YU Yongqiang; WANG Bin

    2009-01-01

    This paper gives a definition of earth system model and shows three development phases of it, including physical climate system model, earth climate system model, and earth system model, based on an inves-tigation of climate system models in the world. It provides an expatiation on the strategic significance of future development of earth system model, an introduction of some representative scientific research plans on development of earth system model home and abroad, and a review of its status and trends based on the models of the fourth assessment report (AR4) of the Intergovernmental Panel on Climate Change (IPCC).Some suggestions on future development of earth system model in China are given, which are expected to be helpful to advance the development.

  20. FORMULATION AND IN VITRO EVALUATION OF METOPROLOL SUCCINATE FLOATING TABLETS BY USING TWO VISCOSITY GRADE OF HPMC

    Directory of Open Access Journals (Sweden)

    Shubhrajit Mantry et al

    2012-09-01

    Full Text Available Metoprolol is a beta1-selective (cardio selective adrenergic receptor blocking agent used in the treatment of Hypertension. The purpose of this investigation is to improve bioavailability by preparing a gastroretentive drug delivery system. Floating tablets of Metoprolol Succinate were prepared by employing two different grades of HPMC K4M and HPMC E15M in different concentrations by effervescent granulation technique. These grades of HPMC K4M and HPMC E15M were evaluated for their gel forming properties. Sodium bicarbonate was incorporated as a gas-generating agent. The tablets were evaluated for uniformity of weight, hardness, friability, drug content, in vitro buoyancy and dissolution studies. The prepared tablets exhibited satisfactory physicochemical characteristics. All the prepared batches showed good in vitro buoyancy. The tablet swelled radially and axially during in vitro buoyancy studies. It was observed that the tablet remained buoyant for 6-8 hours. A combination of 5:1 sodium bicarbonate and magnesium stearate was found to achieve optimum in vitro buoyancy. The tablets with HPMC K4M and HPMC E15M with drug in the ratio of 1:1:2 were found to float for longer duration and released found to be 98.98%. FTIR show that there is no interaction with drug and other excipients. Selected Formulation F4 were subjected to FTIR that shows that is compatible and release was found superior to marketed conventional tablets with respect to floating and found to be stable.

  1. Effect of repeated compaction of tablets on tablet properties and work of compaction using an instrumented laboratory tablet press.

    Science.gov (United States)

    Gamlen, Michael John Desmond; Martini, Luigi G; Al Obaidy, Kais G

    2015-01-01

    The repeated compaction of Avicel PH101, dicalcium phosphate dihydrate (DCP) powder, 50:50 DCP/Avicel PH101 and Starch 1500 was studied using an instrumented laboratory tablet press which measures upper punch force, punch displacement and ejection force and operates using a V-shaped compression profile. The measurement of work compaction was demonstrated, and the test materials were ranked in order of compaction behaviour Avicel PH101 > DCP/Avicel PH101 > Starch > DCP. The behaviour of the DCP/Avicel PH101 mixture was distinctly non-linear compared with the pure components. Repeated compaction and precompression had no effect on the tensile fracture strength of Avicel PH101 tablets, although small effects on friability and disintegration time were seen. Repeated compaction and precompression reduced the tensile strength and the increased disintegration time of the DCP tablets, but improved the strength and friability of Starch 1500 tablets. Based on the data reported, routine laboratory measurement of tablet work of compaction may have potential as a critical quality attribute of a powder blend for compression. The instrumented press was suitable for student use with minimal supervisor input.

  2. Astronomy Learning Activities for Tablets

    Science.gov (United States)

    Pilachowski, Catherine A.; Morris, Frank

    2015-08-01

    Four web-based tools allow students to manipulate astronomical data to learn concepts in astronomy. The tools are HTML5, CSS3, Javascript-based applications that provide access to the content on iPad and Android tablets. The first tool “Three Color” allows students to combine monochrome astronomical images taken through different color filters or in different wavelength regions into a single color image. The second tool “Star Clusters” allows students to compare images of stars in clusters with a pre-defined template of colors and sizes in order to produce color-magnitude diagrams to determine cluster ages. The third tool adapts Travis Rector’s “NovaSearch” to allow students to examine images of the central regions of the Andromeda Galaxy to find novae. After students find a nova, they are able to measure the time over which the nova fades away. A fourth tool, Proper Pair, allows students to interact with Hipparcos data to evaluate close double stars are physical binaries or chance superpositions. Further information and access to these web-based tools are available at www.astro.indiana.edu/ala/.

  3. Swallowing a cellular automaton pill: predicting drug release from a matrix tablet

    CERN Document Server

    Buchla, Ezra; Najera, Aisha; Radunskaya, Ami

    2012-01-01

    Matrix tablets are drug delivery devices designed to release a drug in a controlled manner over an extended period of time. We develop a cellular automaton (CA) model for the dissolution and release of a water-soluble drug and excipient from a matrix tablet of water-insoluble polymer. Cells of the CA are occupied by drug, excipient, water or polymer and the CA updating rules simulate the dissolution of drug and excipient and the subsequent diffusion of the dissolved substances. In addition we simulate the possible fracture of brittle drug and excipient powders during the tablet compression and the melting of the polymer during a possible thermal curing process. Different stirring mechanisms that facilitate the transport of dissolved drug in the fluid in which the tablet is immersed are modeled in the water cells adjacent to the boundary of the tablet. We find that our simulations can reproduce experimental drug release profiles. Our simulation tool can be used to streamline the formulation and production of s...

  4. Application of a newly developed portable NIR imaging device to monitor the dissolution process of tablets.

    Science.gov (United States)

    Ishikawa, Daitaro; Murayama, Kodai; Awa, Kimie; Genkawa, Takuma; Komiyama, Makoto; Kazarian, Sergei G; Ozaki, Yukihiro

    2013-11-01

    We have recently developed a novel portable NIR imaging device (D-NIRs), which has a high speed and high wavelength resolution. This NIR imaging approach has been developed by utilizing D-NIRs for studying the dissolution of a model tablet containing 20 % ascorbic acid (AsA) as an active pharmaceutical ingredient and 80 % hydroxypropyl methylcellulose, where the tablet is sealed by a special cell. Diffuse reflectance NIR spectra in the 1,000 to 1,600 nm region were measured during the dissolution of the tablet. A unique band at around 1,361 nm of AsA was identified by the second derivative spectra of tablet and used for AsA distribution NIR imaging. Two-dimensional change of AsA concentration of the tablet due to water penetration is clearly shown by using the band-based image at 1,361 nm in NIR spectra obtained with high speed. Moreover, it is significantly enhanced by using the intensity ratio of two bands at 1,361 and 1,354 nm corresponding to AsA and water absorption, respectively, showing the dissolution process. The imaging results suggest that the amount of AsA in the imaged area decreases with increasing water penetration. The proposed NIR imaging approach using the intensity of a specific band or the ratio of two bands combined with the developed portable NIR imaging instrument, is a potentially useful practical way to evaluate the tablet at every moment during dissolution and to monitor the concentration distribution of each drug component in the tablet.

  5. Formulation design and optimization of fast dissolving clonazepam tablets by sublimation method

    Directory of Open Access Journals (Sweden)

    S B Shirsand

    2011-01-01

    Full Text Available Fast dissolving tablets of clonazepam were prepared by sublimation method with a view to enhance patient compliance. A 3² full factorial design was applied to investigate the combined effect of two formulation variables: amount of croscarmellose sodium and camphor. Croscarmellose sodium (2-8% w/w was used as superdisintegrant and camphor (20-40% w/w was used as subliming agent, to increase the porosity of the tablets, since it helps water to penetrate into the tablets, along with directly compressible mannitol to enhance mouth feel. The tablets were evaluated for hardness, friability, thickness, drug content uniformity, in vitro dispersion time, wetting time and water absorption ratio. Based on in vitro dispersion time (approximately 11 s; the formulation containing 5% w/w croscarmellose sodium and 40% w/w camphor was found to be promising and tested for in vitro drug release pattern (in pH 6.8 phosphate buffer. Short-term stability (at 40°/75% relative humidity for 3 mo and drug-excipient interaction. Surface response plots are presented to graphically represent the effect of independent variables on the in vitro dispersion time. The validity of the generated mathematical model was tested by preparing two extra-design checkpoints. The optimized tablet formulation was compared with conventional commercial tablet formulation for drug release profiles. This formulation showed nearly nine-fold faster drug release (t 50% 1.8 min compared to the conventional commercial tablet formulation (t 50% 16.4 min. Short-term stability studies on the formulation indicated that there are no significant changes in drug content and in vitro dispersion time (P<0.05.

  6. Formulation design and optimization of fast dissolving clonazepam tablets by sublimation method.

    Science.gov (United States)

    Shirsand, S B; Suresh, Sarasija; Kusumdevi, V; Swamy, P V

    2011-09-01

    Fast dissolving tablets of clonazepam were prepared by sublimation method with a view to enhance patient compliance. A 3(2) full factorial design was applied to investigate the combined effect of two formulation variables: amount of croscarmellose sodium and camphor. Croscarmellose sodium (2-8% w/w) was used as superdisintegrant and camphor (20-40% w/w) was used as subliming agent, to increase the porosity of the tablets, since it helps water to penetrate into the tablets, along with directly compressible mannitol to enhance mouth feel. The tablets were evaluated for hardness, friability, thickness, drug content uniformity, in vitro dispersion time, wetting time and water absorption ratio. Based on in vitro dispersion time (approximately 11 s); the formulation containing 5% w/w croscarmellose sodium and 40% w/w camphor was found to be promising and tested for in vitro drug release pattern (in pH 6.8 phosphate buffer). Short-term stability (at 40°/75% relative humidity for 3 mo) and drug-excipient interaction. Surface response plots are presented to graphically represent the effect of independent variables on the in vitro dispersion time. The validity of the generated mathematical model was tested by preparing two extra-design checkpoints. The optimized tablet formulation was compared with conventional commercial tablet formulation for drug release profiles. This formulation showed nearly nine-fold faster drug release (t(50%) 1.8 min) compared to the conventional commercial tablet formulation (t(50%) 16.4 min). Short-term stability studies on the formulation indicated that there are no significant changes in drug content and in vitro dispersion time (P<0.05).

  7. [Explore Xueshuan Xinmaining tablet effecting on treatment outcome of coronary heart disease based on propensity score].

    Science.gov (United States)

    Li, Yuan; Xie, Yan-ming; Liu, Yan; Zhao, Wei

    2015-12-01

    Xueshuan Xinmaining tablet is a Chinese patent medicine for treating chest pain caused by blood stasis. It is widely used in clinical prevention and treatment of coronary heart disease. In order to understand the treatment effect of Xueshuan Xinmaining tablet in patients with coronary heart disease, we extracted electronic medical record data from 18 large hospitals nationwide. We matched the coronary artery disease patients with or without Xueshuan Xinmaining tablet treatment on gender, age, condition at admission and whether combined with cardiac insufficiency on a one to one ratio. After matching, both groups, patients using Xueshuan Xinmaining tablet (group A) and patients not using Xueshuan Xinmaining tablet (group B), ended up with 1,122 people. In order to evaluate the effectiveness of treatment, the endpoint of effective group was defined as "cure" and "better" while the endpoint of invalid group was defined as "invalid" and "death". Chi-square test showed a statistical significant difference (P coronary heart disease, with a higher efficiency in Xueshuan Xinmaining group. Classic logistic regression analysis showed no statistical significant difference between the two groups on treatment outcome efficiency. Generalized boosted models (GBM) and propensity score (PS) weighted Logistic regression were then applied to balance 45 variables between the two groups. The results showed a regression coefficient greater than 0 and a statistical significant difference (P coronary heart disease patients using Xueshuan Xinmaining tablet had a higher efficiency in clinical efficiency than the patients not using Xueshuan Xinmaining tablet. Since this study did not certainly eliminate all the possible confounders and patients from the hospitals included in this study were not yet well represent the overall situation of the source population, the study conclusion only provided drug use reference for clinical doctors for coronary heart disease. Large randomized controlled

  8. Controlled release of metformin hydrochloride and repaglinide from sandwiched osmotic pump tablet.

    Science.gov (United States)

    Qin, Chao; He, Wei; Zhu, Chunli; Wu, Mengmeng; Jin, Zhu; Zhang, Qiang; Wang, Guangji; Yin, Lifang

    2014-05-15

    The marketed compound tablet of metformin hydrochloride (MH) and repaglinide (RG) exhibits perfect multidrug therapeutic effect of type 2 diabetes. However, due to the short half life of the drugs, the tablet has to be administered 2 to 3 times a day, causing inconvenience to patient and fluctuations of plasma concentration. Here, a sandwiched osmotic pump tablet was developed to deliver the two drugs simultaneously at zero-order rate, in which MH and RG were loaded in different layers separated by a push layer. The osmotic pump tablet was prepared by a combination of three tableting procedure and film coating method. The factors including type and amount of propellant, osmotic active agents, amount of porogenic agent, coating weight, orifice diameter were optimized. The pharmacokinetic study was performed in beagle dogs, and the drug concentration in plasma samples was assayed by HPLC-MS/MS method. Simultaneous, controlled release of MH and RG in the first 12 and 8h was achieved from the optimized formulation. A significantly decreased Cmax, prolonged Tmax and satisfactory bioavailability of the osmotic pump tablet were obtained, and a good in vivo-in vitro correlation of the two drugs was also established. In summary, the sandwiched osmotic pump tablet released the MH and RG simultaneously at zero-order rate, and exhibited significant sustained release effect in vivo and good in vivo-in vitro correlation. The designed controlled release system for MH and RG proposed a promising replacement for the marked compound product in the therapy of type 2 diabetes.

  9. System identification application using Hammerstein model

    Indian Academy of Sciences (India)

    SABAN OZER; HASAN ZORLU; SELCUK METE

    2016-06-01

    Generally, memoryless polynomial nonlinear model for nonlinear part and finite impulse response (FIR) model or infinite impulse response model for linear part are preferred in Hammerstein models in literature. In this paper, system identification applications of Hammerstein model that is cascade of nonlinear second order volterra and linear FIR model are studied. Recursive least square algorithm is used to identify the proposed Hammerstein model parameters. Furthermore, the results are compared to identify the success of proposed Hammerstein model and different types of models

  10. Modeling of economic systems with Petri nets

    Directory of Open Access Journals (Sweden)

    Pavel Valeryevich Skorodumov

    2014-09-01

    Full Text Available Modeling is one of the most important tools to study complex systems. Components of both continuous and discrete nature are present in the behavior of contemporary economic systems. The article uses formalism of nested hybrid Petri nets as a tool to study complex economic systems. The author describes basic approaches of simulation modelling, concepts of classical Petri nets, modified means of nested hybrid Petri nets, benefits of their use for systems modeling. The article presents the concept of a universal system of simulation modeling. On the basis of considered approaches the article proposes to develop a universal system of simulation modeling on the basis of the modified machine Petri nets

  11. Effect of Green Tea-Added Tablets on Volatile Sulfur-Containing Compounds in the Oral Cavity.

    Science.gov (United States)

    Porciani, Pier Francesco; Grandini, Simone

    2016-12-01

    A controlled, clinical, double-blind, cross-over study was conducted to assess the efficacy of sugar-free tablets containing green tea extract on oral volatile sulfur-containing compounds (VSC) versus placebo tablets for 30 minutes. To join the study, subjects had to have at least 24 teeth, no report of oral and systemic diseases, and no removable dentures. All eligible participants had to avoid professional oral hygiene and drugs for two weeks, to not be menstruating, to avoid brushing their teeth and tongue, to not smoke, to not consume alcohol, coffee or tea, nor onion, garlic, or licorice for six hours before the test. Moreover, they had to score a level of VSC ≥ 75 ppb at the basal measurement. Subjects were entered into their respective groups after a minimum 48-hour wash-out period. The test tablet (0.7 g) contained 0.05% green tea extract (equivalent of 1 mg polyphenols for three tablets); the control tablet was identical but without the active agent. The OralChroma2™ device was utilized to evaluate VSC in the oral air. The levels were recorded at baseline, after sucking three tablets in succession, and after 30 minutes. Data were analyzed with SPSS software and significance was set at α = 0.05. 54 subjects completed the trial (23 men, 31 women). None reported problems linked to green tea. The mean reductions in VSC level from baseline at the end of tablet sucking were 34% (p green tea extract can statistically significantly reduce the oral VSC levels immediately, and after 30 minutes. Moreover, the test tablets reduced oral VSC significantly more than the control tablets.

  12. Fast dispersible/slow releasing ibuprofen tablets.

    Science.gov (United States)

    Fini, Adamo; Bergamante, Valentina; Ceschel, Gian Carlo; Ronchi, Celestino; de Moraes, Carlos Alberto Fonseca

    2008-05-01

    Eight formulations were developed containing ibuprofen in the form of orally disintegrating tablets. To prevent bitter taste and side effects of the drug, the drug was associated with Phospholipon 80H, a saturated lecithin, by wet granulation. The granules were then coated using different film forming agents (Kollicoat SR 30, Amprac 01, Kollidon 90F, Eudragit RD 100) obtaining four lots 1-4. Coated granules were then formulated with a sweetener (Aspartame), a mannitol-based diluent (Pearlitol SD 200) and Kollidon CL (1-4K) or Explotab (1-4E) were added as superdisintegrants and compacted under low compression force. The eight lots of tablets, 1-4K and 1-4E, were assessed if suitable as oral disintegrating tablets by determination of a range of technological parameters. Wetting and disintegregation time matched with the requirements of EP IV Ed., for almost all these formulations. Dissolution profiles suggested that the combined action of the hydrophobic lecithin and the coating delay the release of the drug from tablets with respect to when it is free or in the form of simple granules. By an appropriate combination of excipients it was thus possible to obtain orally disintegrating tablets and a delayed release of ibuprofen using simple and conventional techniques.

  13. Characterization of the Roman curse tablet

    Science.gov (United States)

    Liu, Wen; Zhang, Boyang; Fu, Lin

    2017-08-01

    The Roman curse tablet, produced in ancient Rome period, is a metal plate that inscribed with curses. In this research, several techniques were used to find out the physical structure and chemical composition of the Roman curse tablet, and testified the hypothesis that whether the tablet is made of pure lead or lead alloy. A sample of Roman Curse Tablet from the Johns Hopkins Archaeological Museum was analyzed using several different characterization techniques to determine the physical structure and chemical composition. The characterization techniques used were including optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and differential scanning calorimetry (DSC). Because of the small sample size, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and X-ray fluorescence (XRF) cannot test the sample. Results from optical microscopy and SEM, enlarged images of the sample surface were studied. The result revealed that the sample surface has a rough, non-uniform, and grainy surface. AFM provides three-dimensional topography of the sample surface, studying the sample surface in atomic level. DSC studies the thermal property, which is most likely a lead-alloy, not a pure lead. However, none of these tests indicated anything about the chemical composition. Future work will be required due to the lack of measures finding out its chemical composition. Therefore, from these characterization techniques above, the Roman curse tablet sample is consisted of lead alloy, not pure lead.

  14. Molecular dynamic simulations of ocular tablet dissolution.

    Science.gov (United States)

    Ru, Qian; Fadda, Hala M; Li, Chung; Paul, Daniel; Khaw, Peng T; Brocchini, Steve; Zloh, Mire

    2013-11-25

    Small tablets for implantation into the subconjunctival space in the eye are being developed to inhibit scarring after glaucoma filtration surgery (GFS). There is a need to evaluate drug dissolution at the molecular level to determine how the chemical structure of the active may correlate with dissolution in the nonsink conditions of the conjunctival space. We conducted molecular dynamics simulations to study the dissolution process of tablets derived from two drugs that can inhibit fibrosis after GFS, 5-fluorouracil (5-FU) and the matrix metalloprotease inhibitor (MMPi), ilomastat. The dissolution was simulated in the presence of simple point charge (SPC) water molecules, and the liquid turnover of the aqueous humor in the subconjunctival space was simulated by removal of the dissolved drug molecules at regular intervals and replacement by new water molecules. At the end of the simulation, the total molecular solvent accessible surface area of 5-FU tablets increased by 60 times more than that of ilomastat as a result of tablet swelling and release of molecules into solution. The tablet dissolution pattern shown in our molecular dynamic simulations tends to correlate with experimental release profiles. This work indicates that a series of molecular dynamic simulations can be used to predict the influence of the molecular properties of a drug on its dissolution profile and could be useful during preformulation where sufficient amounts of the drug are not always available to perform dissolution studies.

  15. Modeling Power Systems as Complex Adaptive Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.

    2004-12-30

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.

  16. The Women at work in the Linear B Tablets

    DEFF Research Database (Denmark)

    Nosch, Marie-Louise Bech

    2003-01-01

    The article investigates the role of women in Mycenaean society according to the Linear B tablets......The article investigates the role of women in Mycenaean society according to the Linear B tablets...

  17. Neuman systems model in holland: an update.

    Science.gov (United States)

    Merks, André; Verberk, Frans; de Kuiper, Marlou; Lowry, Lois W

    2012-10-01

    The authors of this column, leading members of the International Neuman Systems Model Association, provide an update on the use of Neuman systems model in Holland and document the various changes in The Netherlands that have influenced the use of the model in that country. The model's link to systems theory and stress theory are discussed, as well as a shift to greater emphasis on patient self-management. The model is also linked to healthcare quality improvement and interprofessional collaboration in Holland.

  18. High-throughput prediction of tablet weight and trimethoprim content of compound sulfamethoxazole tablets for controlling the uniformity of dosage units by NIR.

    Science.gov (United States)

    Dong, Yanhong; Li, Juan; Zhong, Xiaoxiao; Cao, Liya; Luo, Yang; Fan, Qi

    2016-04-15

    This paper establishes a novel method to simultaneously predict the tablet weight (TW) and trimethoprim (TMP) content of compound sulfamethoxazole tablets (SMZCO) by near infrared (NIR) spectroscopy with partial least squares (PLS) regression for controlling the uniformity of dosage units (UODU). The NIR spectra for 257 samples were measured using the optimized parameter values and pretreated using the optimized chemometric techniques. After the outliers were ignored, two PLS models for predicting TW and TMP content were respectively established by using the selected spectral sub-ranges and the reference values. The TW model reaches the correlation coefficient of calibration (R(c)) 0.9543 and the TMP content model has the R(c) 0.9205. The experimental results indicate that this strategy expands the NIR application in controlling UODU, especially in the high-throughput and rapid analysis of TWs and contents of the compound pharmaceutical tablets, and may be an important complement to the common NIR on-line analytical method for pharmaceutical tablets.

  19. New model systems for experimental evolution.

    Science.gov (United States)

    Collins, Sinéad

    2013-07-01

    Microbial experimental evolution uses a few well-characterized model systems to answer fundamental questions about how evolution works. This special section highlights novel model systems for experimental evolution, with a focus on marine model systems that can be used to understand evolutionary responses to global change in the oceans.

  20. Performance modeling of automated manufacturing systems

    Science.gov (United States)

    Viswanadham, N.; Narahari, Y.

    A unified and systematic treatment is presented of modeling methodologies and analysis techniques for performance evaluation of automated manufacturing systems. The book is the first treatment of the mathematical modeling of manufacturing systems. Automated manufacturing systems are surveyed and three principal analytical modeling paradigms are discussed: Markov chains, queues and queueing networks, and Petri nets.

  1. Modeling human operator involvement in robotic systems

    NARCIS (Netherlands)

    Wewerinke, P.H.

    1991-01-01

    A modeling approach is presented to describe complex manned robotic systems. The robotic system is modeled as a (highly) nonlinear, possibly time-varying dynamic system including any time delays in terms of optimal estimation, control and decision theory. The role of the human operator(s) is modeled

  2. Visual computing model for immune system and medical system.

    Science.gov (United States)

    Gong, Tao; Cao, Xinxue; Xiong, Qin

    2015-01-01

    Natural immune system is an intelligent self-organizing and adaptive system, which has a variety of immune cells with different types of immune mechanisms. The mutual cooperation between the immune cells shows the intelligence of this immune system, and modeling this immune system has an important significance in medical science and engineering. In order to build a comprehensible model of this immune system for better understanding with the visualization method than the traditional mathematic model, a visual computing model of this immune system was proposed and also used to design a medical system with the immune system, in this paper. Some visual simulations of the immune system were made to test the visual effect. The experimental results of the simulations show that the visual modeling approach can provide a more effective way for analyzing this immune system than only the traditional mathematic equations.

  3. What Works Clearinghouse Quick Review: "Conceptualizing Astronomical Scale: Virtual Simulations on Handheld Tablet Computers Reverse Misconceptions"

    Science.gov (United States)

    What Works Clearinghouse, 2014

    2014-01-01

    This study examined how using two different ways of displaying the solar system--a true-to-scale mode vs. an orrery mode--affected students' knowledge of astronomical concepts. Solar system displays were presented in a software application on a handheld tablet computer. In the true-to-scale mode, users navigated a simulated three-dimensional solar…

  4. Externalizing Behaviour for Analysing System Models

    NARCIS (Netherlands)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, René Rydhof; Kammüller, Florian

    Systems models have recently been introduced to model organisationsandevaluate their vulnerability to threats and especially insiderthreats. Especially for the latter these models are very suitable, since insiders can be assumed to have more knowledge about the attacked organisation than outside

  5. CONTROL SYSTEM IDENTIFICATION THROUGH MODEL MODULATION METHODS

    Science.gov (United States)

    identification has been achieved by using model modulation techniques to drive dynamic models into correspondence with operating control systems. The system ... identification then proceeded from examination of the model and the adaptive loop. The model modulation techniques applied to adaptive control

  6. Evaluation of Certain Pharmaceutical Quality Attributes of Lisinopril Split Tablets

    OpenAIRE

    Khairi M.S. Fahelelbom; Moawia M. M. Al-Tabakha; Nermin A. M. Eissa; Jeevani Javadi

    2016-01-01

    Tablet splitting is an accepted practice for the administration of drugs for a variety of reasons, including dose adjustment, ease of swallowing and cost savings. The purpose of this study was to evaluate the physical properties of lisinopril tablets as a result of splitting the tablets either by hand or with a splitting device. The impact of the splitting technique of lisinopril (Zestril® tablets, 20 mg) on certain physical parameters such as weight variation, friability, disintegration, dis...

  7. Two sustainable energy system analysis models

    DEFF Research Database (Denmark)

    Lund, Henrik; Goran Krajacic, Neven Duic; da Graca Carvalho, Maria

    2005-01-01

    This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy.......This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy....

  8. A phytosterol enriched refined extract of Brassica campestris L. pollen significantly improves benign prostatic hyperplasia (BPH) in a rat model as compared to the classical TCM pollen preparation Qianlie Kang Pule'an Tablets.

    Science.gov (United States)

    Wang, Ruwei; Kobayashi, Yuta; Lin, Yu; Rauwald, Hans Wilhelm; Fang, Ling; Qiao, Hongxiang; Kuchta, Kenny

    2015-01-15

    In Qinghai Province, the Brassica campestris L. pollen preparation Qianlie Kang Pule'an Tablet (QKPT) is traditionally used for BPH therapy. However, in QKPT the content of supposedly active phytosterols is relatively low at 2.59%, necessitating high doses for successful therapy. Therefore, a phytosterol enriched (4.54%) refined extract of B. campestris pollen (PE) was developed and compared with QKPT in a BPH rat model. Six groups of rats (n=8 each), namely sham-operated distilled water control, castrated distilled water control, castrated QKPT 2.0g/kg, castrated PE 0.1g/kg, castrated PE 0.2g/kg, and castrated PE 0.4g/kg, were intragastrically treated with the respective daily doses. Testosterone propionate (0.3mg/day) was administered to all castrated rats, while the sham-operated group received placebo injections. After 30 days, the animals were sacrificed and prostates as well as seminal vesicles excised and weighted in order to calculate prostate volume index (PVI) as well as prostate index (PI) and seminal vesicle index (SVI), defined as organ weight in g per 100g body weight. Compared with sham-operated controls, PI (p<0.01), PVI (p<0.01), and SVI (p<0.01) were all significantly increased in all castrated, testosterone treated rats. After treatment with PE at 0.4 and 0.2g/kg or QKPT at 2.0g/kg per day, both indices were significantly reduced (p<0.01) as compared to the castrated distilled water control. For PE at 0.1g/kg per day only PI was significantly reduced (p<0.05). At the highest PE concentration of 0.4g/kg per day both PI and SVI were also significantly reduced when compared to the QKPT group (p<0.05). Both PE and QKPT demonstrated curative effects against BPH in the applied animal model. In its highest dose at 0.4g/kg per day, PE was clearly superior to QKPT.

  9. Physicochemical properties and mechanism of drug release from ethyl cellulose matrix tablets prepared by direct compression and hot-melt extrusion.

    Science.gov (United States)

    Crowley, Michael M; Schroeder, Britta; Fredersdorf, Anke; Obara, Sakae; Talarico, Mark; Kucera, Shawn; McGinity, James W

    2004-01-28

    The objective of this research project was to determine the physicochemical properties and investigate the drug release mechanism from ethyl cellulose (EC) matrix tablets prepared by either direct compression or hot-melt extrusion (HME) of binary mixtures of water soluble drug (guaifenesin) and the polymer. Ethyl cellulose was separated into "fine" or "coarse" particle size fractions corresponding to 325-80 and 80-30 mesh particles, respectively. Tablets containing 30% guaifenesin were prepared at 10, 30, or 50 kN compaction forces and extruded at processing temperatures of 80-90 and 90-110 degrees C. The drug dissolution and release kinetics were determined and the tablet pore characteristics, tortuosity, thermal properties and surface morphologies were studied using helium pycnometry, mercury porosimetry, differential scanning calorimetry and scanning electron microscopy. The tortuosity was measured directly by a novel technique that allows for the calculation of diffusion coefficients in three experiments. The Higuchi diffusion model, Percolation Theory and Polymer Free Volume Theory were applied to the dissolution data to explain the release properties of drug from the matrix systems. The release rate was shown to be dependent on the ethyl cellulose particle size, compaction force and extrusion temperature.

  10. In vitro release kinetics and bioavailability of gastroretentive cinnarizine hydrochloride tablet.

    Science.gov (United States)

    Nagarwal, Ramesh C; Ridhurkar, Devendra N; Pandit, J K

    2010-03-01

    An oral sustained release dosage form of cinnarizine HCl (CNZ) based on gastric floating matrix tablets was studied. The release of CNZ from different floating matrix formulations containing four viscosity grades of hydroxypropyl methylcellulose, sodium alginate or polyethylene oxide, and gas-forming agent (sodium bicarbonate or calcium carbonate) was studied in simulated gastric fluid (pH 1.2). CNZ release data from the matrix tablets were analyzed kinetically using Higuchi, Peppas, Weibull, and Vergnaud models. From water uptake, matrix erosion studies, and drug release data, the overall release mechanism can be explained as a result of rapid hydration of polymer on the surface of the floating tablet and formation of a gel layer surrounding the matrix that controls water penetration into its center. On the basis of in vitro release data, batch HP1 (CNZ, HPMC-K100LV, SBC, LTS, and MgS) was subjected to bioavailability studies in rabbits and was compared with CNZ suspension. It was concluded that the greater bioavailability of HP1 was due to its longer retention in the gastric environment of the test animal. Batch no. HP1 of floating tablet in rabbits demonstrated that the floating tablet CNZ could be a 24-h sustained release formulation.

  11. Monitorization of drug content in furosemide and lorazepam tablets stored in multidose pill boxes

    Directory of Open Access Journals (Sweden)

    Jessica Martins

    2010-01-01

    Full Text Available Background : Therapeutic nonadherence is a major health problem, particularly when therapeutic regimens are complex and long-lasting. Therefore, tools such as multidose pill boxes have been designed to provide the means for higher therapeutic compliance. However, no studies are available reporting on their capacity to keep the drug content of the stored tablets unaltered. Objective : This work aimed at monitoring the drug content of tablets stored in multidose boxes for a period of two weeks. Materials and Methods : Furosemide and lorazepam were selected as model drugs, given their frequent chronic use, which is coherent with the profile of medicines susceptible of storage in the referred boxes. Variations of the tablets drug content were assessed as a function of temperature (25°C and 40°C and the presence of blister. Results and Discussion : The obtained results allowed concluding that concerning temperature, only lorazepam tablets registered drug content alterations and only when stored at 40°C. On the other side, it was concluded that the absence of blister does not compromise the drug content of the studied tablets. Conclusion : In the specific conditions of this study, the storage of these medicines in multidose boxes is considered reliable and adequate.

  12. Formulation and evaluation of once daily minocycline hydrochloride extended release matrix tablets

    Directory of Open Access Journals (Sweden)

    Keny R

    2009-01-01

    Full Text Available The present study was aimed to develop once daily extended release matrix tablets of minocycline hydrochloride, using hydroxypropylmethylcellulose either alone or in combination with ethyl cellulose as the matrix material in different proportions. The formulated tablets were also compared with a marketed product. The results of the dissolution study indicate that formulations FC-IV, FC-V and FC-VI showed maximum drug release upto 24 h, whereas the marketed product was found to extend the release only up to 14 h. Incase of formulations containing combination of hydroxypropylmethylcellulose and ethyl cellulose (FC-I to FC-IX, the release of the drug was found to be dependent on the relative proportions of hydroxypropylmethylcellulose and ethyl cellulose used in the tablet matrix. Mathematical treatment of the in vitro drug release data suggests that, all the formulations best fitted into first order release kinetics. Drug release from the matrix occurred by combination of two mechanisms, diffusion of drug from tablet matrix and erosion of tablet surface, which was reflected from Higuchi′s model and Erosion plot.

  13. The performance of HPMC matrix tablets using various agglomeration manufacturing processes.

    Science.gov (United States)

    Košir, Darjan; Vrečer, Franc

    2017-02-01

    The flow and compaction properties of a compaction mixture or powder and the drug-release profile of final tablets are important critical quality attributes (CQAs) that have an impact on the overall performance of hydrophilic matrix tablets. The selection of granulation method can importantly affect these CQAs. This study investigates various agglomeration methods of sustained-release formulation using HPMC K4M as a release polymer with various wet- and dry-granulation techniques. Flow properties were determined using flow time, angle of response, and the Carr index. Compaction properties were evaluated using "out of die" Heckel model. Release of carvedilol was tested as 12-h drug-dissolution profile. Compression mixtures made using the wet-granulation method exhibit better flow and compression properties than compression mixtures made using the dry-granulation method. The direct compression method proved to be the least appropriate manufacturing method because the compression mixture has very poor flow and the lowest compressibility/compactibility index. The choice of granulation technique significantly influences the swelling behavior and drug-dissolution profile of the final matrix tablets, also resulting in dissimilar release profiles. The choice of granulation method has the greatest influence on the drug-release profile. The direct compression method provides tablets with the fastest drug-release profile, followed by the dry-granulation and wet-granulation methods. The particle size of granules and porosity of tablets play an important role, contributing to differences in drug-release profiles.

  14. Astronomical Content in Rongorongo Tablet Keiti

    DEFF Research Database (Denmark)

    Wieczorek, Rafal

    2011-01-01

    Th e fi eld of rongorongo research: the study of Easter Island’s native script is in a peculiar state at the moment. While relative progress has been made in structural and statistical analysis in the last decades, at the level of both single glyphs as well as entire texts, little to no advancement...... has been achieved in the actual decipherment. To shed new light on rongorongo research, a hypothesis regarding the contents of tablet Keiti, one of the 25 obtained artifacts, is proposed. Th e content, as well as the meaning, of all but one of these 25 rongorongo texts is still unknown....... In this publication, an interpretation for the recto side of tablet Keiti is presented. It is argued that the tablet contains astronomical observations or instructions regarding the Rapa Nui lunar calendar, and is similar in content to the only other rongorongo text whose function has been partially ascertained...

  15. Tablet Keiti: Does it Contain Astronomical Instructions?

    DEFF Research Database (Denmark)

    Wieczorek, Rafal

    2010-01-01

    consists of 9 to 11 conserved glyphs, among which we find two moon glyphs. Moon glyphs can be engraved in two forms: facing right (encoded as 040) and facing left (041). In Keiti's alpha sequence we encounter right and left facing moon glyphs at seemingly random intervals. However, closer examination...... tablet Mamari”. In the four lines of this tablet, also known as rongorongo text C, we encounter 30 moon glyphs arranged in a pattern that mirrors the Rapa Nui lunar calendar as recorded by early Western visitors. This presentation argues that yet another rongorongo item – tablet Keiti, also known as text...... of moon glyphs in the alpha sequence shows that they are arranged in a pattern that can be interpreted as a list of ten months, whose length varies between 29 and 30 days, thus approximating the natural length of 29,5 days per month....

  16. Astronomical Content in Rongorongo Tablet Keiti

    DEFF Research Database (Denmark)

    Wieczorek, Rafal

    2011-01-01

    Th e fi eld of rongorongo research: the study of Easter Island’s native script is in a peculiar state at the moment. While relative progress has been made in structural and statistical analysis in the last decades, at the level of both single glyphs as well as entire texts, little to no advancement...... has been achieved in the actual decipherment. To shed new light on rongorongo research, a hypothesis regarding the contents of tablet Keiti, one of the 25 obtained artifacts, is proposed. Th e content, as well as the meaning, of all but one of these 25 rongorongo texts is still unknown....... In this publication, an interpretation for the recto side of tablet Keiti is presented. It is argued that the tablet contains astronomical observations or instructions regarding the Rapa Nui lunar calendar, and is similar in content to the only other rongorongo text whose function has been partially ascertained...

  17. 21 CFR 520.1200 - Ivermectin, fenbendazole, and praziquantel tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ivermectin, fenbendazole, and praziquantel tablets... Ivermectin, fenbendazole, and praziquantel tablets. (a) Specifications. Each chewable tablet contains either: (1) 68 micrograms (µg) ivermectin, 1.134 grams fenbendazole, and 57 milligrams (mg) praziquantel;...

  18. 21 CFR 520.622a - Diethylcarbamazine citrate tablets.

    Science.gov (United States)

    2010-04-01

    ..., and 400 milligram tablets for prevention of heartworm disease in dogs and as an aid in the treatment..., 200, and 300 milligram tablets for prevention of heartworm disease in dogs and as an aid in the..., 200, 300, or 400 milligram tablets for prevention of heartworm disease in dogs, as an aid in...

  19. [Formulation of calcium carbonate tablets with various binding substances].

    Science.gov (United States)

    Gazikalović, E; Obrenović, D; Nidzović, Z; Toskić-Radojicić, M

    1996-01-01

    The test results of calcium carbonate tablets, made of different binding substances (microcrystal cellulose, gelatin, 7pp sodium carboxymethylcellulose and starch) were presented. The content of calcium-carbonate in tablets as well as varying, solidity, prodigality and aptness to decay was determined. The best properties were observed in tablets made with starch.

  20. Detection of the breakage of pharmaceutical tablets in pneumatic transport.

    Science.gov (United States)

    Albion, Katherine; Briens, Lauren; Briens, Cedric; Berruti, Franco

    2006-09-28

    Pneumatic transport of pharmaceutical tablets is very convenient, compact and greatly reduces contamination. A potential problem, however, is the breakage of a significant fraction of the transported tablets, causing serious product quality problems. Since the flowrate of tablets transported through a given pneumatic transport line increases with gas velocity, lines are often operated at gas velocities slightly below the velocity at which tablets break. Minor changes in operating conditions can have a large effect on the impact resistance of tablets and on the observed tablet breakage rate. Therefore, maintaining a constant gas velocity is not sufficient to keep the tablet breakage rate below an acceptable level. The objective of the present study was to develop a reliable and non-invasive on-line method for the detection of tablet breakage. Pharmaceutical acetaminophen tablets were transported pneumatically in a 0.1 m diameter pipeline consisting of a 5 m vertical and a 4.0 m horizontal section made of either re-enforced PVC or steel. The pipeline flow regime was determined by visual observation through clear pipeline sections. Tablet breakage was quantified by screening tablet samples. Acoustic measurements were recorded at different locations along the pipeline. Analysis of the signals from microphones attached to the wall of the elbow and horizontal section provided a reliable detection of conditions leading to tablet breakage.

  1. 21 CFR 520.784 - Doxylamine succinate tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Doxylamine succinate tablets. 520.784 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.784 Doxylamine succinate tablets. (a) Specifications. The drug is in tablet form and contains doxylamine succinate as...

  2. 21 CFR 520.434 - Chlorphenesin carbamate tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chlorphenesin carbamate tablets. 520.434 Section... Chlorphenesin carbamate tablets. (a) Specifications. Each tablet contains 400 milligrams of chlorphenesin carbamate. (b) Sponsor. See No. 000009 in § 510.600(c) of this chapter. (c) Conditions of use in dogs—(1...

  3. Early clinical development of artemether-lumefantrine dispersible tablet: palatability of three flavours and bioavailability in healthy subjects

    Directory of Open Access Journals (Sweden)

    Abdulla Salim

    2010-09-01

    Full Text Available Abstract Background Efforts to ease administration and enhance acceptability of the oral anti-malarial artemether-lumefantrine (A-L crushed tablet to infants and children triggered the development of a novel dispersible tablet of A-L. During early development of this new formulation, two studies were performed in healthy subjects, one to evaluate the palatability of three flavours of A-L, and a second one to compare the bioavailability of active principles between the dispersible tablet and the tablet (administered crushed and intact. Methods Study 1 was performed in 48 healthy schoolchildren in Tanzania. Within 1 day, all subjects tasted a strawberry-, orange- and cherry-flavoured oral A-L suspension for 10 seconds (without swallowing in a randomized, single-blind, crossover fashion. The palatability of each formulation was rated using a visual analogue scale (VAS. Study 2 was an open, randomized crossover trial in 48 healthy adults given single doses of A-L (80 mg artemether + 480 mg lumefantrine with food. The objectives were to compare the bioavailability of artemether, dihydroartemisinin (DHA and lumefantrine between the dispersible tablet and the tablet administered crushed (primary objective and intact (secondary objective. Results Study 1 showed no statistically significant difference in VAS scores between the three flavours but cherry had the highest score in several ratings (particularly for overall liking. Study 2 demonstrated that the dispersible and crushed tablets delivered bioequivalent artemether, DHA and lumefantrine systemic exposure (area under the curve [AUC]; mean ± SD AUC0-tlast were 208 ± 113 vs 195 ± 93 h.ng/ml for artemether, 206 ± 81 vs 199 ± 84 h.ng/ml for DHA and 262 ± 107 vs 291 ± 106 h.μg/ml for lumefantrine. Bioequivalence was also shown for peak plasma concentrations (Cmax of DHA and lumefantrine. Compared with the intact tablet, the dispersible tablet resulted in bioequivalent lumefantrine exposure, but

  4. Can a tablet device alter undergraduate science students' study behavior and use of technology?

    Science.gov (United States)

    Morris, Neil P; Ramsay, Luke; Chauhan, Vikesh

    2012-06-01

    This article reports findings from a study investigating undergraduate biological sciences students' use of technology and computer devices for learning and the effect of providing students with a tablet device. A controlled study was conducted to collect quantitative and qualitative data on the impact of a tablet device on students' use of devices and technology for learning. Overall, we found that students made extensive use of the tablet device for learning, using it in preference to laptop computers to retrieve information, record lectures, and access learning resources. In line with other studies, we found that undergraduate students only use familiar Web 2.0 technologies and that the tablet device did not alter this behavior for the majority of tools. We conclude that undergraduate science students can make extensive use of a tablet device to enhance their learning opportunities without institutions changing their teaching methods or computer systems, but that institutional intervention may be needed to drive changes in student behavior toward the use of novel Web 2.0 technologies.

  5. A novel electrostatic dry powder coating process for pharmaceutical dosage forms: immediate release coatings for tablets.

    Science.gov (United States)

    Qiao, Mingxi; Zhang, Liqiang; Ma, Yingliang; Zhu, Jesse; Chow, Kwok

    2010-10-01

    An electrostatic dry powder coating process for pharmaceutical solid dosage forms was developed for the first time by electrostatic dry powder coating in a pan coater system. Two immediate release coating compositions with Opadry® AMB and Eudragit® EPO were successfully applied using this process. A liquid plasticizer was sprayed onto the surface of the tablet cores to increase the conductivity of tablet cores to enhance particle deposition, electrical resistivity reduced from greater than 1×10(13)Ωm to less than 1×10(9)Ωm, and to lower the glass transition temperature (T(g)) of the coating polymer for film forming in the pan coater. The application of liquid plasticizer was followed by spraying charged coating particles using an electrostatic charging gun to enhance the uniform deposition on tablet surface. The coating particles were coalesced into a thin film by curing at an acceptable processing temperature as formation was confirmed by SEM micrographs. The results also show that the optimized dry powder coating process produces tablets with smooth surface, good coating uniformity and release profile that are comparable to that of the tablet cores. The data also suggest that this novel electrostatic dry powder coating technique is an alternative to aqueous- or solvent-based coating process for pharmaceutical products. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  6. Use of tablet personal computers for sensitive patient-reported information.

    Science.gov (United States)

    Dupont, Alexandra; Wheeler, Jane; Herndon, James E; Coan, April; Zafar, S Yousuf; Hood, Linda; Patwardhan, Meenal; Shaw, Heather S; Lyerly, H Kim; Abernethy, Amy P

    2009-01-01

    Notebook-style computers (e/Tablets) are increasingly replacing paper methods for collecting patient-reported information. Discrepancies in data between these methods have been found in oncology for sexuality-related questions. A study was performed to formulate hypotheses regarding causes for discrepant responses and to analyze whether electronic data collection adds value over paper-based methods when collecting data on sensitive topics. A total of 56 breast cancer patients visiting Duke Breast Clinic (North Carolina) participated by responding to 12 subscales of 5 survey instruments in electronic (e/Tablet) format and to a paper version of 1 of these surveys, at each visit. Twenty-one participants (38%) provided dissimilar responses on paper and electronic surveys to one item of the Functional Assessment of Cancer Therapy-General (FACT-G) Social Well-Being scale that asked patients to rate their satisfaction with their current sex life. Among these 21 patients were 8 patients who answered the question in the electronic environment, and 13 patients who answered both paper and electronic versions but with different responses. Eleven patients (29%) did not respond to the item on either e/Tablet or paper; 45 patients (80%) answered it on e/Tablet; and 37 patients (66%) responded on the paper version. The e/Tablet electronic system may provide a "safer" environment than paper questionnaires for cancer patients to answer private or highly personal questions on sensitive topics such as sexuality.

  7. In-vitro evaluation of enteric coated insulin tablets containing absorption enhancer and enzyme inhibitor.

    Science.gov (United States)

    Wong, Chun Y; Martinez, Jorge; Carnagarin, Revathy; Dass, Crispin R

    2017-03-01

    The aim of this study was to develop an enteric coated insulin tablet formulation using polymers, absorption enhancer and enzyme inhibitor, which protect the tablets in acidic pH and enhance systemic bioavailability. In this study, the influence of coating by cellulose acetate hydrogen phthalate solution and chosen excipients on Glut-4 transporter translocation in C2C12 skeletal muscle cells was examined. Following the determination of optimum number of coating layers, two dissolution buffers such as 0.01 m hydrochloric acid, pH 2, and 50 mm phosphate, pH 7.4, were employed to determine the in-vitro release of insulin. Insulin was protected by the coating during the dissolution process. Five (5-CL) coating layers and eight (8-CL) coating layers had minimal insulin release in hydrochloric acid, but not three (3-CL) coating layers. Glut-4 translocation in C2C12 cells was promoted by the chosen excipients. No detrimental metabolic effects were observed in these cells. To date, limited studies combine the overall effectiveness of multiple excipients. Our study showed that the coated tablets have an immediate release effect in phosphate buffer. In Glut-4 translocation assay, insulin was still functional after releasing from the tablet. Such tablet formulation can be potentially beneficial to type 1 diabetes patients. © 2017 Royal Pharmaceutical Society.

  8. Verapamil hydrochloride release characteristics from new copolymer zwitterionic matrix tablets.

    Science.gov (United States)

    Kostova, Bistra; Kamenska, Elena; Ivanov, Ivo; Momekov, George; Rachev, Dimitar; Georgiev, George

    2008-01-01

    The aim of this study was to synthesize stable copolymer (vinyl acetate-co-3-dimethyl[methacryloyloxyethyl] ammonium propane sulfinate) zwitterionic latex with different compositions for the first time by emulsifier-free emulsion copolymerization. Throughout the course of the study, a proposal was made for the explanation of the relationship between the "overshooting" phenomenon (a swelling kinetics with a maximum) and the specific self-association of the zwitterionic copolymers. The zwitterionic monomer unit mole fraction, pH, and ionic strength effects on this relationship, on the swelling kinetics of the zwitterionic copolymers, and on the sustained verapamil hydrochloride release from the model tablets were established by the study's authors.

  9. Graphical Model Debugger Framework for Embedded Systems

    DEFF Research Database (Denmark)

    Zeng, Kebin; Guo, Yu; Angelov, Christo K.

    2010-01-01

    Model Driven Software Development has offered a faster way to design and implement embedded real-time software by moving the design to a model level, and by transforming models to code. However, the testing of embedded systems has remained at the code level. This paper presents a Graphical Model...... Debugger Framework, providing an auxiliary avenue of analysis of system models at runtime by executing generated code and updating models synchronously, which allows embedded developers to focus on the model level. With the model debugger, embedded developers can graphically test their design model...

  10. Particle Tracking Model (PTM) with Coastal Modeling System (CMS)

    Science.gov (United States)

    2014-10-31

    System ( CMS ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER...www.erdc.usace.army.mil/Missions/WaterResources/CIRP.aspx Coastal Inlets Research Program Particle Tracking Model (PTM) with Coastal Modeling System ( CMS ) The...System ( CMS ), which provides coupled wave and current forcing for PTM simulations. CMS -PTM is implemented in the Surface-water Modeling System, a

  11. Analysis hierarchical model for discrete event systems

    Science.gov (United States)

    Ciortea, E. M.

    2015-11-01

    The This paper presents the hierarchical model based on discrete event network for robotic systems. Based on the hierarchical approach, Petri network is analysed as a network of the highest conceptual level and the lowest level of local control. For modelling and control of complex robotic systems using extended Petri nets. Such a system is structured, controlled and analysed in this paper by using Visual Object Net ++ package that is relatively simple and easy to use, and the results are shown as representations easy to interpret. The hierarchical structure of the robotic system is implemented on computers analysed using specialized programs. Implementation of hierarchical model discrete event systems, as a real-time operating system on a computer network connected via a serial bus is possible, where each computer is dedicated to local and Petri model of a subsystem global robotic system. Since Petri models are simplified to apply general computers, analysis, modelling, complex manufacturing systems control can be achieved using Petri nets. Discrete event systems is a pragmatic tool for modelling industrial systems. For system modelling using Petri nets because we have our system where discrete event. To highlight the auxiliary time Petri model using transport stream divided into hierarchical levels and sections are analysed successively. Proposed robotic system simulation using timed Petri, offers the opportunity to view the robotic time. Application of goods or robotic and transmission times obtained by measuring spot is obtained graphics showing the average time for transport activity, using the parameters sets of finished products. individually.

  12. Development of dissolution method for benznidazole tablets

    Directory of Open Access Journals (Sweden)

    Ádley Antonini Neves de Lima

    2009-01-01

    Full Text Available The aim of this work was the development of a dissolution method for benznidazole (BNZ tablets. Three different types of dissolution media, two stirring speeds and apparatus 2 (paddle were used. The accomplishment of the drug dissolution profiles was compared through the dissolution efficiency. The assay was performed by spectrophotometry at 324 nm. The better conditions were: sodium chloridehydrochloride acid buffer pH 1.2 with stirring speed of 75 rpm, volume of 900 mL and paddle as apparatus. Ahead of the results it can be concluded that the method developed consists in an efficient alternative for assays of dissolution for benznidazole tablets.

  13. Electronic acquisition of OSCE performance using tablets.

    Science.gov (United States)

    Hochlehnert, Achim; Schultz, Jobst-Hendrik; Möltner, Andreas; Tımbıl, Sevgi; Brass, Konstantin; Jünger, Jana

    2015-01-01

    Hintergrund: OSCE-Prüfungen sind oft mit einem erheblichen Material- und Organisationsaufwand verbunden, da die Leistungserfassung üblicherweise auf Papier durchgeführt wird. Eine elektronisch unterstützte Durchführung stellt hierzu eine Alternative dar, mit der der Verbrauch materieller Ressourcen reduziert werden kann. Insbesondere erscheint hier der Einsatz von Tablets sinnvoll, da diese zudem leicht zu transportieren sind und damit flexibel eingesetzt werden können. Zielsetzung: Die Nutzerakzeptanz der Verwendung von Tablets bei OSCE-Prüfungen wurde bislang allerdings nur wenig untersucht. Ziel dieser Studie war daher eine Evaluation Tablet-basierter OSCE-Prüfungen aus Sicht der Benutzer (Prüfer) und der geprüften Studierenden.Methodik: Bei zwei OSCE-Prüfungen des Faches Innere Medizin der Universität Heidelberg wurde die Nutzerakzeptanz einer Tablet-basierten Durchführung (Zufriedenheit mit der Funktionalität) und die subjektive Anstrengung aus Sicht der Prüfer untersucht. Hierzu wurden standardisierte Fragebögen und halbstandardisierte Interviews eingesetzt (Vollerfassung aller teilnehmenden Prüfer). Zudem wurde bei einer der Prüfungen die subjektive Bewertung dieser Prüfungsvariante an einer Stichprobe teilnehmender Studierender mittels halbstandardisierter Interviews erhoben.Ergebnisse: Die Prüfer waren mit der Tablet-Prüfungsvariante insgesamt sehr zufrieden. Die subjektive Anstrengung der Bedienung der Tablets wurde im Mittel als „kaum anstrengend“ empfunden. In den Interviews wurden insbesondere die einfache Handhabung und die geringe Fehleranfälligkeit von den Prüfern als Vorteile dieser Prüfungsvariante genannt. In der Befragung der geprüften Studierenden zeigte sich ebenfalls eine Akzeptanz der Tablet-Prüfungsvariante. Diskussion: Insgesamt hat sich gezeigt, dass der Einsatz von Tablets in OSCE-Prüfungen sowohl von Prüfern als auch Studierenden gut angenommen wird. Es wird erwartet, dass diese Prüfungsvariante auch

  14. Application of Neem Gum for Aqueous Film Coating of Ciprofloxacin Tablets

    Directory of Open Access Journals (Sweden)

    A P Kulkarni

    2013-05-01

    Full Text Available Summary. At present the pharmaceutical industry and academia are focusing on the use of natural materials and resources for development of pharmaceutical product. In previous study, neem gum (NG, obtained from Azadirachata indica plant revealed satisfactory film forming ability. The present study evaluates the application potential of neem gum, as an aqueous film coating material, using ciprofloxacin hydrchloride (drug as a model drug. Initial study of physical mixture indicated absence of chemical interaction in between drug and NG. Aqueous coating solution of NG was optimized and consisted of neem gum (13.34%w/w, triethyl citrate (1.25%w/w, talc (0.25%w/w and titanium dioxide (0.17%w/w. The coating parameters such as pan revolutions (rpm, inlet air pressure, inlet temperature, and pan load were optimized. The uncoated and coated tablets were evaluated for hardness, disintegration time, dissolution, drug content. The coated tablets were subjected to accelerated stability conditions for 1 month and the results were compared with marketed drug tablet. Any coating defects, except surface roughness, were absent in case of NG coated tablets. NG coated tablets depicted satisfactory mechanical strength. Dissolution study of NG coated tablets depicted 90% of drug release in 10 minutes and 100% of drug release at 30minutes. Accelerated storage conditions didn’t affect the tablet hardness and % drug release. The coating process efficiency, coating uniformity and loss on drying confirmed that the coating solution was optimum and coating parameters were robust. Industrial relevance. A paradigm shift, from organic solvent-based to water-based film coating of pharmaceutical dosage forms, apparent in pharmaceutical industries, is due to Government regulation, high cost of the organic solvents, safety issues associated with the use of organic solvents. Currently, the commercially available edible coatings utilize synthetic cellulosic polymers namely

  15. Preparation of fenofibrate immediate-release tablets involving wet grinding for improved bioavailability.

    Science.gov (United States)

    Zhang, Lili; Chai, Guihong; Zeng, Xueping; He, Haibing; Xu, Hui; Tang, Xing

    2010-09-01

    The purpose of this study was to investigate the dissolution and oral bioavailability of an immediate-release tablet involving wet grinding of a poorly water-soluble drug, fenofibrate. The milled suspension was prepared using a Basket Dispersing Mill in the presence of a hydrophilic polymer solution and then granulated with common excipients, and compressed into an immediate-release tablet with blank microcrystalline cellulose granules. Compared with unmilled tablets (56% within 30 minutes), the dissolution of wet-milled tablets (about 98% in 30 minutes) was markedly enhanced. No significant decrease in the dissolution rate (96% in 30 minutes) of the wet-milled tablet was observed after 3 months under 40 degrees C and 75% relative humidity storage. In addition, the oral bioavailability of the wet-milled tablets (test) and Lipanthyl supra-bioavailability tablets (reference) was determined in beagle dogs after a single dose (160 mg fenofibrate) in a randomized crossover, own-control study. The results suggested that both the area under the plasma concentration-time curve (AUC((0-t)) = 46.83 +/- 11.09 microg/mL h) and the mean peak concentration of the test (C(max) = 4.63 +/- 1.71 microg/mL) were higher than the reference (AUC((0-t)) = 35.12 +/- 10.97 microg/mL h, C(max) = 2.11 +/- 0.08 microg/mL). The relative bioavailability of the wet-milled tablet was approximately 1.3-fold higher. Furthermore, the apparent rate of absorption of fenofibrate from the wet-milled tablet (T(max) = 2.63 hours) was faster than that from Lipanthyl (T(max) = 3.75 hours). These results indicated that the dissolution and the bioavailability of fenofibrate were significantly enhanced by wet-grinding process. So, this shows that wet grinding is a powerful technique to improve the bioavailability for poorly water-soluble drugs, especially for Biopharmaceutics Classification System Class II compounds.

  16. Extensions in model-based system analysis

    OpenAIRE

    Graham, Matthew R.

    2007-01-01

    Model-based system analysis techniques provide a means for determining desired system performance prior to actual implementation. In addition to specifying desired performance, model-based analysis techniques require mathematical descriptions that characterize relevant behavior of the system. The developments of this dissertation give ex. tended formulation