Patel S.H.,Polymer Processing Institute |
Bakeev K.A.,CAMO Software Inc. |
Chen G.,U.S. Army |
Zhang Q.,Polymer Processing Institute |
Advances in Polymer Technology | Year: 2010
A number of vinyl acetate-alcohol resins (VAAR) samples were collected during partial hydrolysis of poly(vinyl acetate) at different conversions levels (<30%). Using these VAAR samples with known OH (hydroxyl) content, it has been demonstrated that near infrared (NIR) spectroscopic data produced a near perfect fit for the calibration of OH content. A 4-factor partial least-squares method was employed and gave the best results. Further work also confirmed that NIR, operating at a well-controlled environment, is able to quantify, with great precision, the OH content of the selected model compound. In the case for the OH content analysis of VAAR resins, solvent mix ratio (methyl acetate: methanol) and temperature have been identified to be the two most influential factors on the analytical results. © 2010 Wiley Periodicals, Inc.
Krizsan S.J.,Swedish University of Agricultural Sciences |
Krizsan S.J.,Norwegian University of Life Sciences |
Randby A.T.,Norwegian University of Life Sciences |
Westad F.,Camo Software Inc.
Grass and Forage Science | Year: 2012
The objective of this study was to identify and quantify fermentation end-products, detected with chromatographic techniques, that were negatively related to intake of grass silage by cattle. Further, the aim was to verify the intake-depressing effect of these compounds in a feeding trial. A set of twenty-four silages that had been used in a previous study to model variations in intake owing to fermentation quality was reanalysed with liquid and gas chromatography. Known and unknown chromatogram peaks were subjected to a regression analysis to determine which were negatively related to intake. Compounds were identified and quantified using a liquid chromatography-mass spectrometry system; acetic acid (AcA), caproic acid and tryptamine were chosen for verification. Growing steers were offered wilted silage with these three compounds added, separately or as a mixture, in proportions similar to the maximum values detected in the silages of the previous study. Dietary addition of AcA, either separately or mixed with the other two compounds, reduced silage dry matter (DM) intake. However, the reduction in silage DM intake equalled the amount provided by the added substances, so that no differences in total DM intake were observed for any of the dietary treatments. © 2012 Blackwell Publishing Ltd.
Barnes S.E.,Glaxosmithkline |
Thurston T.,Glaxosmithkline |
Coleman J.A.,Glaxosmithkline |
Diederich A.,Glaxosmithkline |
And 5 more authors.
Analytical Methods | Year: 2010
We report the successful application of in situ diffuse reflectance near-infrared (NIR) spectroscopy for characterization of the solvent mediated polymorphic form transformation of pazopanib hydrochloride. Crystal form is a critical quality attribute (CQA) for this active pharmaceutical ingredient (API) to ensure appropriate levels of exposure in patients. NIR spectroscopy was implemented to monitor this final stage unit operation in real-time on manufacturing scale. This technique provided an automated in situ method to replace labour intensive off-line qualitative testing and manual sampling. A partial least squares (PLS) model was created using NIR data collected during an early manufacturing campaign and a novel strategy based on interval-PLS was used to select and optimize the model parameters. The model was subsequently implemented on plant scale and used to monitor clinical manufacturing campaigns. The PLS method clearly differentiated between the monohydrate and the desired anhydrous form allowing determination of the transformation end point in real-time. Utilisation of PLS diagnostics such as Mahalanobis distance and spectral residuals provided additional capability to signal any unexpected behaviour in the process and/or indicate the presence of an undesired solvate polymorph also seen during process development. © 2010 The Royal Society of Chemistry.
Swarbrick B.,CAMO Software Inc.
Journal of Near Infrared Spectroscopy | Year: 2014
Smaller, faster and more robust instrumentation combined with improved regulatory and industry guidance and advanced data management systems have all contributed to making the near infrared (NIR) spectroscopy technique a viable alternative to traditional in-process and final-release testing strategies in the pharmaceutical/biopharmaceutical industry. The NIR method cannot be used to replace all testing methods, but when it can be applied, it provides greater insights into the state of a process or product. It also provides real-or near-real-time quality information, allowing process operators, Quality Assurance personnel or Advanced Process Control systems to take a proactive, rather than reactive, approach to quality during the manufacturing process. This review summarises the developments in instrumentation, regulatory/industry guidance and information management systems that better enable the implementation of NIR technology into routine laboratory and process applications. A short review comparing the NIR and Raman techniques is provided, outlining the complementary nature of the two methods along with a discussion on how the two methodologies have experienced a similar evolution over the past 14 years. © IM Publications LLP 2014 All rights reserved.