In-line Near-infrared Spectroscopy Research Articles

Comparison of Methods for Transfer of Calibration Models in Near-Infared Spectroscopy: A Case Study Based on Correcting Path Length Differences Using Fiber-Optic Transmittance Probes in In-Line Near-Infrared Spectroscopy

This article addresses problems related to transfer of calibration models due to variations in distance between the transmittance fiber-optic probes. The data have been generated using a mixture design and measured at five different probe distances. A number of techniques reported in the literature have been compared. These include multiplicative scatter correction (MSC), path length correction (PLC), finite impulse response (FIR), orthogonal signal correction (OSC), piecewise direct standardization (PDS), and robust calibration. The quality of the predictions was expressed in terms of root mean square error of prediction (RMSEP). Robust calibration gave good calibration transfer results, while the other methods did not give acceptable results.

Use of In-Line Near-Infrared Spectroscopy in Combination with Chemometrics for Improved Understanding of Pharmaceutical Processes

High shear granulation is a complex unit operation with several interacting process parameters. No generally accepted real-time in-line tools are available to gain insight into this process, and in practice, a highly experienced process formulator and operator are needed to develop a wet granulated solid dosage form. In this study, the use of in-line near-infrared (NIR) spectroscopy as a process analytical tool for high shear granulation was investigated. In combination with principal component-based methods, process analysis of three separate phases of high shear wet granulation (mixing, spraying, and wet massing) was facilitated. Critical information, both chemical and physical, was collected during processing. Chemical information included the homogeneity of the formulation and the amount of water in wet mass. In addition, physical information related to the particle size of granules was extracted. Principal component loadings were fully interpreted to validate the conclusions drawn from scores and predictions. Thus NIR spectroscopy could be used to determine the end points of the three subphases of high shear wet granulation and, as such, provide a fast in-line quality control tool.

Reaction monitoring in supercritical carbon dioxide‐based processes using in‐line NIR spectroscopy and on‐line gas chromatography

Chemie Ingenieur TechnikVolume 76, Issue 9 p. 1368-1369 Poster Reaction monitoring in supercritical carbon dioxide-based processes using in-line NIR spectroscopy and on-line gas chromatography G. Wiegand Dr., G. Wiegand Dr. gabriele.wiegand@itc-cpv.fzk.de Search for more papers by this authorJ. Bürck Dr., J. Bürck Dr. ITC-CPV, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 KarlsruheSearch for more papers by this authorS. Roth, S. Roth ITC-CPV, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 KarlsruheSearch for more papers by this authorH. Mathieu, H. Mathieu ITC-CPV, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 KarlsruheSearch for more papers by this author G. Wiegand Dr., G. Wiegand Dr. gabriele.wiegand@itc-cpv.fzk.de Search for more papers by this authorJ. Bürck Dr., J. Bürck Dr. ITC-CPV, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 KarlsruheSearch for more papers by this authorS. Roth, S. Roth ITC-CPV, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 KarlsruheSearch for more papers by this authorH. Mathieu, H. Mathieu ITC-CPV, Forschungszentrum Karlsruhe, Postfach 3640, D-76021 KarlsruheSearch for more papers by this author First published: 01 October 2004 https://doi.org/10.1002/cite.200490267AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume76, Issue9September, 2004Pages 1368-1369 RelatedInformation

In-Line near Infrared Spectroscopy for Use in Product and Process Monitoring in the Food Industry

The article describes a case study based on implementation of in-line near infrared (NIR) spectroscopy using fibre-optic transmittance probes. This study is based on an experimental design incorporating raw materials and process variables, a split-plot design. The results show that in-line NIR spectroscopy can be used for monitoring and predicting parameters related to both the input parameters (raw materials and process variables) and the final product quality (viscosity of the product) for emulsion-based products in the food industry. However, the results are dependent on the proper choice of validation of the calibration models. The article also proposes a way to update calibration models in situations when new changes not accounted for in the calibration model are experienced.

Process analysis of fluidized bed granulation

This study assesses the fluidized bed granulation process for the optimization of a model formulation using in-line near-infrared (NIR) spectroscopy for moisture determination. The granulation process was analyzed using an automated granulator and optimization of the verapamil hydrochloride formulation was performed using a mixture design. The NIR setup with a fixed wavelength detector was applied for moisture measurement. Information from other process measurements, temperature difference between process inlet air and granules (T(diff)), and water content of process air (AH), was also analyzed. The application of in-line NIR provided information related to the amount of water throughout the whole granulation process. This information combined with trend charts of T(diff) and AH enabled the analysis of the different process phases. By this means, we can obtain in-line documentation from all the steps of the processing. The choice of the excipient affected the nature of the solid-water interactions; this resulted in varying process times. NIR moisture measurement combined with temperature and humidity measurements provides a tool for the control of water during fluid bed granulation.

In-Line NIR Monitoring of Composition and Bubble Formation in Polystyrene/Blowing Agent Mixtures

The composition of mixtures of polystyrene (PS) and blowing agent (HCFC 142b) was monitored by means of near infrared (NIR) transmission probes located in the die at the end of an intermeshing co-rotating twin-screw extruder. The PS resin was extruded while the HCFC was injected at high pressure and various concentrations. Using chemometrics techniques like PLS to model the differences in the NIR spectra, the composition of PS/HCFC mixtures could be predicted accurately with a standard error of prediction (SEP) below 0.2 wt%. Accurate composition prediction was still possible in the presence of a small amount (<5% wt) of nucleating agent like talc. In-line NIR spectroscopy was also an effective technique to detect bubble formation in the die as a function of HCFC concentration and pressure.