131,487 research outputs found
Design of experiments methodology in studying near-infrared spectral information of model intact tablets : simultaneous determination of metoprolol tartrate and hydrochlorothiazide in solid dosage forms and powder compressibility assessment using near-infrared spectroscopy
No full textNear-infrared spectroscopy (NIRS) is applied in pharmaceutical industry for monitoring drug content during tablet manufacturing process. NIRS method, once developed and validated, is used over years and it is of critical importance to insure method robustness towards formulation, process, instrumental, acquisition and environmental factors. Design of Experiments (DoE) methodology was proposed in this work for systematic study of the effect of compression pressure, pre-compression pressure and tableting speed on Average Euclidean Distance (AED) which reflects NIR spectral features of the studied caffeine tablets, and Root Mean Squared Error of Prediction (RMSEP) as a key performance indicator of the developed NIRS calibration model for caffeine content prediction. Study was performed in diffuse reflectance (DR) and diffuse transmittance (DT) measurement mode. Tableting factors shown to have significant influence on the studied responses have been considered in the development of the robust calibration models in DR and DT mode, using Global Calibration Model (GCM) approach. Three studied factors have shown to be significant in DR mode whereas, compression pressure and tableting speed have shown significant effect on the studied responses in DT mode. Developed robust method in DT mode have shown superior performances compared to DR mode, exhibiting total error (RMSEP) of 1.21 % calculated on the independent test set. DoE setup, with the selection of factors and responses adopted in this study was not reported elsewhere.
Simultaneous NIRS quantification of two APIs in powders and tablets requires several challenges to be overcome. Overlapping absorption peaks of formulation components result in method specificity problem. Strategy for selecting the samples used for developing the prediction models is needed. Robustness of the method towards formulation factors needs to be assessed due to complex formulation. Fast and simple method for simultaneous quantification of Hydrochlorothiazide (HTZ) and Metoprolol Tartrate (MTP) in powders and tablets was proposed in work. Simulation of industrial scale tablet machine using tablet press replicator - Presster® was proposed as fast and cost-effective alternative for design and manufacture of tablet sets needed for NIRS calibration model development. Balance Reference Method (BRM) was proposed as an alternative to HPLC and UV-spectroscopy which are traditionally used as reference methods in NIRS model development. The proposed experimental setup was suggested for the feasibility study stage of the method development. The two model drugs were simultaneously quantified using NIRS exhibiting RMSEP of 1.69 and 1.31 mg in HTZ powder and tablet samples respectively, while MTP powder and tablet samples were predicted with RMSEP of 3.15 and 3.00 mg respectively. NIRS analysis of Metoprolol Tartrate and Hydrochlorothiazide in powders and tablets was not yet reported in the literature.
The compressibility and compatibility of a powder formulation is conventionally determined by compaction followed by destructive tensile strength and relative density measurement of the final compact. In this study, a non-destructive near-infrared spectroscopic (NIRS) was evaluated for the determination of powder compressibility and compactibility. Twelve different formulations were investigated with 2 batches produced per formulation. Relative density and tensile strength were measured using a traditional, destructive method on one tablet batch and subsequently by a developed non-destructive chemometric NIRS method on the second batch of the particular formulation. The outcomes of the two approaches were compared to validate the developed method. All data sets were fitted to the three established mathematical equations to calculate equation factors, which represent a formulation compressibility and compactibility. The study focus was set on the equation factor comparison between the traditional and the newly designed method. The results have shown a high degree similarity between the outcomes of the two methods. A discrepancy between the two methods was observed for the outcomes of the equation factors after fitting to Leuenberger equation. The approach using NIRS is suggested as a promising tool for monitoring tablet manufacturing process
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
The R&D Tax Incentives
No full textThis article sets out some background information and reflections of the author on the R&D tax incentive schemes included in the Common Corporate Tax Base (CCTB) Proposal. In particular the author analyzes the stimulus to private R&D through ad hoc tax incentives included in the CCTB Proposal and dives into the actual provisions included in the Proposal highlighting the most relevant issues connected with their design and interpretation. Moreover, the author explores the interaction between the CCTB Proposal and the granting by Member States of domestic R&D tax incentives
sj-docx-1-tab-10.1177_1759720X221149965 – Supplemental material for Association between baseline cardiovascular risk and incidence rates of major adverse cardiovascular events and malignancies in patients with psoriatic arthritis and psoriasis receiving tofacitinib
No full textSupplemental material, sj-docx-1-tab-10.1177_1759720X221149965 for Association between baseline cardiovascular risk and incidence rates of major adverse cardiovascular events and malignancies in patients with psoriatic arthritis and psoriasis receiving tofacitinib by Lars E. Kristensen, Bruce Strober, Denis Poddubnyy, Ying-Ying Leung, Hyejin Jo, Kenneth Kwok, Ivana Vranic, Dona L. Fleishaker, Lara Fallon, Arne Yndestad and Dafna D. Gladman in Therapeutic Advances in Musculoskeletal Disease</p
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