Chemical images: Technical approaches and issues

Clark, Don; Šašić, Slobodan

doi:10.1002/cyto.a.20275

Cited by 33 publications

(27 citation statements)

References 11 publications

(8 reference statements)

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“…Future innovations in CI equipment manufacture are likely to depress purchase costs and encourage more widespread utilisation of this emerging technology in the pharmaceutical sector. Compositional information [28], [29] Quality assessment [20], [30] Process related information [31], [32] Blend uniformity [33], [34] Coating thickness [35] Counterfeit drug detection [36], [37] Remote identification [38], [41] Staring imager High throughput analysis [38], [39] [22], [49] Tablet characterisation [17], [29], [50], [51], [52], [53], […”

Section: Discussionmentioning

confidence: 99%

“…One method involves acquisition of simultaneous spectral measurements from a series of adjacent spatial positions -the object is moved underneath an imaging spectrograph in what is known as pushbroom acquisition [16]. This method has been applied for hypercube acquisition in Raman mapping investigations [17] and [18]. Another method involves keeping the image field of view fixed, and obtaining images one wavelength after another in what is known as a staring imager configuration [5].…”

Section: Principles Of Chemical Imagingmentioning

confidence: 99%

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Recent applications of Chemical Imaging to pharmaceutical process monitoring and quality control

Gowen

O’Donnell

Cullen³

et al. 2008

European Journal of Pharmaceutics and Biopharmaceutics

242

150

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Section: Discussionmentioning

confidence: 99%

Section: Principles Of Chemical Imagingmentioning

confidence: 99%

Recent applications of Chemical Imaging to pharmaceutical process monitoring and quality control

Gowen

O’Donnell

Cullen³

et al. 2008

European Journal of Pharmaceutics and Biopharmaceutics

242

150

View full text Add to dashboard Cite

“…The chemical images generated with Raman mapping could easily differentiate between the dry and wet technologies and highlight the number of API pixels present in the mixture. Apart from this, various other publications have also utilized Raman CI (Clark et al, 2006;Doub et al, 2007;Sasic et al, 2008;Kuriyana et al, 2014).…”

Section: Api and Excipient Identificationmentioning

confidence: 99%

Spectroscopic Techniques for Nondestructive Quality Inspection of Pharmaceutical Products: A Review

Kandpal

Park

Tewari

et al. 2015

Journal of Biosystems Engineering

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Spectroscopy is an emerging technology for the quality assessment of pharmaceutical samples, from tablet manufacturing to final quality assurance. The traditional methods for the quality management of pharmaceutical tablets are time consuming and destructive, while spectroscopic techniques allow rapid analysis in a non-destructive manner. The advantage of spectroscopy is that it collects both spatial and spectral information (called hyperspectral imaging), which is useful for the chemical imaging of pharmaceutical samples. These chemical images provide both qualitative and quantitative information on tablet samples. In the pharmaceutics, spectroscopic techniques are used for a variety of applications, such as analysis of the homogeneity of powder samples as well as determination of particle size, product composition, and the concentration, uniformity, and distribution of the active pharmaceutical ingredient in solid tablets. This review paper presents an introduction to the applications of various spectroscopic techniques such as hyperspectroscopy and vibrational spectroscopies (Raman spectroscopy, FT-NIR, and IR spectroscopy) for the quality and safety assessment of pharmaceutical solid dosage forms. In addition, various chemometric techniques that are highly essential for analyzing the spectroscopic data of pharmaceutical samples are also reviewed.

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“…Taking advantage of the chemical information provided by Raman spectral analysis in a confocal microscope, the locations and interactions of specific molecules within cells have been studied (4)(5)(6)(7). Under the right conditions, it is possible to identify and track individual chemical species in a complex background by Raman spectroscopy (8,9).…”

mentioning

confidence: 99%

Raman spectroscopy comes to flow cytometry

Jett

2008

Cytometry Pt A

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ONE thread in the history of flow cytometry is the quest to expand the number of parameters that can be measured for each particle. This expansion has involved both cytochemical probe developments and instrumental innovations. Numerous new fluorescent molecules to quantify cellular components have been developed over the years. The development of fluorescently labeled antibodies that have enabled the dissection of the immune system and signaling pathways is perhaps the most notable. The report by Watson et al. (1) in this issue of Cytometry is the first description of a flow cytometer with sufficient sensitivity and spectral resolution to analyze surface enhanced Raman spectra (SERS) emitted by multiple dyelabeled nanoparticls bound to microspheres.Raman scattered light is ubiquitous. Stokes Raman scattering (2), an inelastic scattering of light, occurs when a photon incident on a molecule excites the molecule into a vibrational, or other type of excited state, and is re-emitted with lower energy or longer wavelength. The difference in energy between the incident and scattered photons is a measure of the energy of the excited state. If the molecule is in an excited state when the incident photon is scattered, it can interact in such a manner as to de-excite the molecule, resulting in the scattered photon being more energetic than the incident photon (Anti-Stokes Raman). The more complex a molecule is, the more virbational modes it has, resulting in Raman spectra that are rich in information and can be quite complex with many sharp features.Although the process is weak, especially compared to fluorescence from fluorophors used in cytometry, the Raman scattered light can interfere with measurements of low levels of fluorescence. One can directly observe Raman scattered light by viewing the region of a flow cytometer that the laser beam passes through. It appears as a faint line of light that is red-shifted from the laser beam. The laser light scatters off of the water molecules in the flow cell and results in photons of two wavelengths. One comes from excitation of the stretching of the OÀ ÀH bonds and the other from a molecular vibration in which the angle between the two H atoms oscillates.Silver and gold nanoparticles that have roughened surfaces greatly enhance Raman scattering of photons by molecules on the surface of the particles. A recent article discusses the mechanisms, which are still a matter of debate, that cause surface enhanced Raman scattering (3). The degree of enhancement can be as much as 14 orders of magnitude over nonenhanced Raman scattering, bright enough to record the SERS emissions from a single molecule (3). Compared to fluorescence, the SERS emissions can be on the same order of brightness as a typical fluorophor. However, the SERS spectra are rich in features that reflect the vibrational modes of the molecules bound to the metal surface.Fluorescence spectra, in general, are quite broad and featureless. Fluorescence emission from the types of dyes used in flow cytometry typically emit o...

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Chemical images: Technical approaches and issues

Cited by 33 publications

References 11 publications

Recent applications of Chemical Imaging to pharmaceutical process monitoring and quality control

Recent applications of Chemical Imaging to pharmaceutical process monitoring and quality control

Spectroscopic Techniques for Nondestructive Quality Inspection of Pharmaceutical Products: A Review

Raman spectroscopy comes to flow cytometry

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