FORMULATION AND IN VITRO EVALUATION OF RAMELTEON TABLETS FOR COLON DRUG DELIVERY SYSTEM BY COMPRESSION COATING

Objective: Ramelteon, is a sleep agent that selectively binds to the MT1 and MT2 receptors in the suprachiasmatic nucleus (SCN), instead of binding to GABAA receptors. In the present research work, the formulation of ramelteon targeted to colon by using various polymers developed. Methods: Colon-targeted tablets were prepared in two steps. Initially, core tablets were prepared and then the tablets were coated by using different pH dependent polymers. Ethylcellulose, Eudragit RLPO and L100 were used as enteric coating polymers. The precompression blend of all formulations was subjected to various flow property tests and all the formulations were passed the tests. The tablets were coated by using polymers and the coated tablets were subjected to physical characterization, drug content, in vitro drug release and kinetics of drug release. Results: Among all the formulations, F4 formulation was found to be optimized as it was retarded the drug release up to 18 h and showed maximum of 99.25% drug release. It followed the first-order kinetics mechanism. All the formulations having Korsmeyer-Peppas ‘n’ values are in the range of 0.540 to 0.818. Hence, it was concluded that the prepared formulations followed non-Fickian diffusion. Conclusion: An effective and stable remelteon colon targeted formulation developed for treating insomnia

Carbon fibers modified with polypyrrole for headspace solid phase microextraction of trace amounts of 2-pentyl furan from breath samples

This study introduces micrometric carbon strands as a suitable fiber for headspace solid phase microextraction. Compared to previous supports, carbon fibers have mechanical flexibility, wide thermal expansion, and a large surface area, which is an important factor in headspace solid phase microextraction. The electrophoretic technique was applied to modify the surface of stainless steel and carbon fibers with polypyrrole. Modified carbon fibers were used for extraction of 2-pentylfuran (2-PF) as a model analyte from patients� breath and coffee samples. 2-PF belongs to the furan family, which was suggested as a biomarker for Aspergillus fumigatus and was classified as a possible carcinogen. 2-PF can be found in many heat-processed foods and drinks. The separation and detection of the analyte was performed by gas chromatography coupled to mass spectrometry. The effective factors in the extraction performance of the analyte by carbon fiber supports were investigated and optimized. Under optimized extraction conditions (temperature, 20 °C; time, 15 min; desorption temperature, 200 °C; desorption time, 2 min; salt concentration, 10 w/v; and stirring rate, 700 rpm), the limit of detection was calculated as 0.05 ng mL�1, whereas repeatability and fiber-to-fiber reproducibility (RSD ) was found to be in the range of 3.2�4.1. The experimental results showed that the proposed fiber had greater extraction performance for 2-pentylfuran. © 201

Design of 16-bit Heterogeneous Adder Architectures Using Different Homogeneous Adders

ABSTRACT: Adders are digital circuits that perform addition operation. There are various types of adder structures such as Ripple carry adder (RCA), carry look ahead adder (CLA) , carry select adder (CSLA) , carry save adder(CSA), carry skip adder, carry increment adder and so on. Again CSLA is of two types that is linear carry select adder (LCSLA) & square root carry select adder (SQRT CSLA). To design an efficient adder circuit in terms of area, power and speed is one of the challenging task in modern VLSI design field. In this paper performance analysis of different adder structures like RCA, CLA, LCSLA and SQRT CSLA has been carried out and then a Heterogeneous adder structure is proposed, which compose of four different sub homogeneous adders (RCA, CLA, LCSLA and SQRT CSLA). The heterogeneous adder structure is used to demonstrate the tradeoffs between the speed and area. In this paper, all adder structures i.e., RCA, CLA, LCSLA and SQRT CSLA are to be designed and are to be compared with each other in terms of delay and area. Then by using the homogeneous adder structures different heterogeneous adder structures of 16-bit size are to be designed. Different heterogeneous adder architectures are compared with each other in terms of delay (ns) and area (number of LUTs). All the adder structures are designed using VHDL with the help of ISE Xilinx design suite 14.2 and functionally simulated using ISIM simulator. All the designs are to be synthesized using Xilinx XST synthesizer

Evaluation of octadecyl-bonded silica membrane disk for extraction of surfactants from water

Octadecyl-bonded silica membrane disk was evaluated for extraction of surfactants from water. Different parameters such as extraction efficiency, maximum capacity of the disk, proper eluent for washing the surfactants from the disk and effect of vacuum pressure on percent recoveries were studied. Results showed that more than 95 percent of surfactants were extracted easily from water, Maximum capacity of the disk was about 5 mg. Also it was determined that this technique compare to liquid/liquid extraction would introduce less error in analytical results

Origin of resistivity anomaly in p-type leads chalcogenide multiphase compounds

The electrical resistivity curves for binary phase compounds of p-type lead chalcogenide (PbTe)(0.9−x)(PbSe)0.1(PbS)x, (x = 0.15, 0.2, 0.25), which contain PbS-rich secondary phases, show different behaviour on heating and cooling between 500-700 K. This is contrast to single phase compounds which exhibit similar behaviour on heating and cooling. We correlate these anomalies in the electrical resistivities of multiphase compounds to the variation in phase composition at high temperatures. The inhomogeneous distribution of dopants between the matrix and secondary phase is found to be crucial in the electronic transport properties of the multiphase compounds. These results can lead to further advances in designing composite Pb-chalcogenides with high thermoelectric performance

Analysis of paraben preservatives in cosmetic samples: Comparison of three different dynamic hollow fiber liquid-phase microextraction methods

This study focused on a comparison of three different dynamic hollow fiber-based liquid-phase microextraction (DHF-LPME) methods for extraction and preconcentration of parabens from wastewater, toothpaste, cream, and shampoo samples. The first method is two-phase DHF-LPME, in which n-octanol was used as the extraction solvent. The second is three-phase DHF-LPME, in which n-octanol and basic aqueous solution were used as the extraction solvent and acceptor phase, respectively. High-performance liquid chromatography with UV detection (HPLC-UV) was applied for determination of the parabens in both methods. The third method is a recently introduced method; three-phase DHF-LPME based on two immiscible organic solvents (n-dodecane as organic solvent and acetonitrile as an acceptor phase). The quantitative analyses were performed by the use of gas chromatography-mass spectrometry (GC-MS) after injection port derivatization. The effect of different extraction conditions (i.e., extraction solvent, pH, ionic strength, stirring rate, and dynamic and extraction times) on the extraction efficiency of the parabens was investigated and optimized. All the three procedures provide similar working parameters characterized by high repeatability (3.9-6.3 %) and good linearity (correlation coefficient ranging from 0.989 to 0.998). Results of real sample analyses obtained by these three methods were highly correlated. Although all methods provide compatible alternatives for paraben analysis, the three-phase DHF-LPME based on two immiscible organic solvents may be a more appropriate technique due to its higher extraction efficiency and thus lower limits of detection (LODs). LODs for all the parabens ranged from 0.2 to 5.0 μg L-1 using the two first methods combined with HPLC-UV. An improvement in sensitivity of several orders of magnitude was achieved using three-phase DHF-LPME based on two immiscible organic solvents followed by single-ion monitoring GC-MS analyses (0.01-0.2 μg L-1) due to compatibility of this technique with GC instrument. © 2013 Springer-Verlag

Damage function for historic paper. Part I: Fitness for use

Background In heritage science literature and in preventive conservation practice, damage functions are used to model material behaviour and specifically damage (unacceptable change), as a result of the presence of a stressor over time. For such functions to be of use in the context of collection management, it is important to define a range of parameters, such as who the stakeholders are (e.g. the public, curators, researchers), the mode of use (e.g. display, storage, manual handling), the long-term planning horizon (i.e. when in the future it is deemed acceptable for an item to become damaged or unfit for use), and what the threshold of damage is, i.e. extent of physical change assessed as damage. Results In this paper, we explore the threshold of fitness for use for archival and library paper documents used for display or reading in the context of access in reading rooms by the general public. Change is considered in the context of discolouration and mechanical deterioration such as tears and missing pieces: forms of physical deterioration that accumulate with time in libraries and archives. We also explore whether the threshold fitness for use is defined differently for objects perceived to be of different value, and for different modes of use. The data were collected in a series of fitness-for-use workshops carried out with readers/visitors in heritage institutions using principles of Design of Experiments. Conclusions The results show that when no particular value is pre-assigned to an archival or library document, missing pieces influenced readers/visitors’ subjective judgements of fitness-for-use to a greater extent than did discolouration and tears (which had little or no influence). This finding was most apparent in the display context in comparison to the reading room context. The finding also best applied when readers/visitors were not given a value scenario (in comparison to when they were asked to think about the document having personal or historic value). It can be estimated that, in general, items become unfit when text is evidently missing. However, if the visitor/reader is prompted to think of a document in terms of its historic value, then change in a document has little impact on fitness for use

An efficient sample preparation method based on dispersive liquid�liquid microextraction associated with back extraction for trace determination of acidic pharmaceuticals

Reduction of matrix effect seems to be a great challenge for the development of a practical method in bioanalysis. In this regard, a simple and efficient DLLME procedure along with a back-extraction step (DLLME-BE) was developed for the preconcentration of four common non-steroidal anti-inflammatory drugs (NSAIDs) in various biological fluid samples. Briefly, the analytes of interest were initially transferred into the extraction solvent followed by the back-extraction into an immiscible basic methanol (as an acceptor phase) for further preconcentration and clean-up. The main purpose of the work is reducing the matrix effect and sensitive determination of target molecules in the complex matrices. Following on, the separation and determination of the analytes were carried out using GC�MS (in-port derivatization) and HPLC-DAD instrument. The influential parameters affecting the DLLME-BE method were evaluated in detail and the best extraction conditions were established. Under the optimum conditions, low method detection limits in the range of 0.1�1.0 and 0.1�6.0 µg L�1 were obtained for GC�MS and HPLC-DAD analysis, respectively. Additionally, fair intra-day precisions of 2.7�14.5 and 2.8�7.8 as well as inter-day precisions of 3.9�14.5 and 3.5�8.1 were achieved for the GC�MS and HPLC-DAD analysis, respectively. Finally, the method was successfully applied for the determination of four common NSAIDs in different biological fluid samples. © 2018 King Saud Universit

An efficient sample preparation method based on dispersive liquid�liquid microextraction associated with back extraction for trace determination of acidic pharmaceuticals

Reduction of matrix effect seems to be a great challenge for the development of a practical method in bioanalysis. In this regard, a simple and efficient DLLME procedure along with a back-extraction step (DLLME-BE) was developed for the preconcentration of four common non-steroidal anti-inflammatory drugs (NSAIDs) in various biological fluid samples. Briefly, the analytes of interest were initially transferred into the extraction solvent followed by the back-extraction into an immiscible basic methanol (as an acceptor phase) for further preconcentration and clean-up. The main purpose of the work is reducing the matrix effect and sensitive determination of target molecules in the complex matrices. Following on, the separation and determination of the analytes were carried out using GC�MS (in-port derivatization) and HPLC-DAD instrument. The influential parameters affecting the DLLME-BE method were evaluated in detail and the best extraction conditions were established. Under the optimum conditions, low method detection limits in the range of 0.1�1.0 and 0.1�6.0 µg L�1 were obtained for GC�MS and HPLC-DAD analysis, respectively. Additionally, fair intra-day precisions of 2.7�14.5 and 2.8�7.8 as well as inter-day precisions of 3.9�14.5 and 3.5�8.1 were achieved for the GC�MS and HPLC-DAD analysis, respectively. Finally, the method was successfully applied for the determination of four common NSAIDs in different biological fluid samples. © 2018 King Saud Universit

Prophylactic Fibrinogen Decreases Postoperative Bleeding but Not Acute Kidney Injury in Patients Undergoing Heart Transplantation

The present study is the premier clinical attempt to scrutinize the practicability of prophylactic fibrinogen infusion in patients undergoing heart transplantation (HT). A total of 67 consecutive patients who had undergone HT between January 2012 and December 2014 were assessed. After exclusion of some patients, 23 patients were given preoperative 2 g fibrinogen concentrate over a period of 15 minutes after the termination of cardiopulmonary bypass pump and complete reversal of heparin, and 30 patients were not given. Some laboratories were measured before general anesthesia and at 6 and 24 hours after surgery. In addition, major adverse events were also evaluated during hospitalization. The mean age of the patients was 39.5 ± 11.4 years, with a predominance of male sex (77.4). All laboratories at baseline were comparable between groups. The length of hospital stay was longer in the control group compared to the fibrinogen group (20 16-22 vs 16 12-19 days; P =.005). There was a trend for patients in the fibrinogen group to have more acute kidney injury (AKI) after surgery (10% vs 30.4%) and less reoperation for bleeding (20% vs 8.7%). The amount of postoperative bleeding was significantly higher in the control group compared to the fibrinogen group (P <.001). The number of packed red blood cell transfused during 24 hours after surgery was significantly lower in the fibrinogen group (P <.001). The transfusion of fibrinogen in patients undergoing HT may be associated with reductions in postoperative bleeding, the number of packed red blood cells, and hospital length of stay; however, it may enhance postoperative AKI. © The Author(s) 2017