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Raman spectroscopy is a well established tool for the analysis of vibration spectra, which then allow for the determination of individual substances in a chemical sample, or for their phase transitions. In the time-resolved-Raman-sprectroscopy the vibration spectra of a chemical sample are recorded sequentially over a time interval, such that conclusions for intermediate products (transients) can be drawn within a chemical process. The observed data-matrix M from a Raman spectroscopy can be regarded as a matrix product of two unknown matrices W and H, where the first is representing the contribution of the spectra and the latter represents the chemical spectra. One approach for obtaining W and H is the non-negative matrix factorization. We propose a novel approach, which does not need the commonly used separability assumption. The performance of this approach is shown on a real world chemical example.
In this paper, we investigate the interconversion processes of the major flame retardant - 1,2,5,6,9,10-hexabromocyclododecane (HBCD) - by the means of statistical thermodynamics based on classical force-fields. Three ideas will be presented. First, the application of classical hybrid Monte-Carlo simulations for quantum mechanical processes will be justified. Second, the problem of insufficient convergence properties of hybrid Monte-Carlo methods for the generation of low temperature canonical ensembles will be solved by an interpolation approach. Furthermore, it will be shown how free energy differences can be used for a rate matrix computation. The results of our numerical simulations will be compared to experimental results.
Guideline ICH Q3D on elemental impurities (EI) was adopted by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) and published in December 2014.
The European Medicines Agency (EMA) Committee for Medicinal Products for Human use (CHMP) adopted guideline Q3D in December 2014 and defined the dates for coming into effect .
ICH Q3D is the first globally harmonised guidance to control 24 elemental impurities in drug products administered by oral, parenteral and inhalation routes. The policy entails a paradigm shift, moving away from substance-based testing towards risk-based assessment and control strategy.
In the context of implementing Q3D in Europe, several texts and monographs of the European Pharmacopoeia (Ph. Eur.) were revised, rendering the guideline legally binding in 38 European countries. Ph. Eur. general chapter 5.20. has been modified to reflect ICH Q3D guideline and the old fashioned heavy metals test, Ph. Eur. 2.4.8., has been deleted from individual Ph. Eur. monographs for substances for human use. Furthermore, general chapter Ph. Eur. 2.4.20. Determination of metal catalyst and metal reagent residues has been completely revised and renamed Determination of elemental impurities.
Whatever the chosen analytical method, reference materials with a known content of the target element are required for the quantification of elemental impurities. This led EDQM to consider the establishment of suitable reference materials. However, due to lack of specific experience and technical equipment, external partners were sought. Three key European institutes (JRC, BAM and PTB) were identified and involved in the project.
To mitigate the overall risk at first the project focussed on the elements classified by ICH Q3D as Class 1: lead, cadmium, mercury and arsenic.
A key necessity was the traceability of the element content to the SI (International System of Units Measurement) to allow metrologically reliable and reproducible determination. This required new and specific approaches to be developed by the partners in charge (BAM and PTB).
Since January 2018 lead solution CRS, cadmium solution CRS, mercury solution CRS and arsenic solution CRS are available to the users of the Ph. Eur. .
Ergopeptides, like ergocornine and a-ergocryptine, exist in an S- and in an R-configuration. Kinetic experiments imply that certain configurations are preferred depending on the solvent. The experimental methods are explained in this article. Furthermore, computational methods are used to understand this configurational preference. Standard quantum chemical methods can predict the favored configurations by using minimum energy calculations on the potential energy landscape. However, the explicit role of the solvent is not revealed by this type of methods. In order to better understand its influence, classical mechanical molecular simulations are applied. It appears from our research that 'folding' the ergopeptide molecules into an intermediate state (between the S- and the R-configuration) is mechanically hindered for the preferred configurations.
Infraredmatrix-assisted laser dispersion and ionization(IR-MALDI) in combination with on mobility (IM) spectrometry enables the direct Analysis of biomolecules in aqueous solution. The release of ions directly from an aqueous solution is based on a phase explosion, induced by the Absorption of an IR laser pulse, which disperses the liquid as vapor, nano- and micro-droplets. The ionization process is characterized initially by a broad spatial distribution of the ions, which is a result of complex fluid dynamics and desolvation kinetics. These processes have a profound effect on the shape and width of the peaks in the IM spectra. In this work, the Transport of ions by the phase explosion-induced shockwave could be studied independently from the transport by the electric field. The shockwave-induced mean velocities of the ions at different time scales were determined through IM spectrometry and shadowgraphy. The results show a deceleration of the Ions from 118m∙s−1 at a distance of 400 μm from the liquid surface to 7.1 m∙s−1 at a distance of 10 mm, which is caused by a pileup effect. Furthermore, the desolvation kinetics were investigated
and a first-order desolvation constant of 325 ± 50 s−1
was obtained. In the second part, the IR-MALDI-IM
spectrometer is used as an HPLC detector for the twodimensional separation of a pesticide mixture.
Elemental impurities (EI) in medicinal products for human use are limited according to ICH guideline Q3D, which is in force since December 2017 in Europe and US.
As a consequenceconsequence, the relevant texts of the European Pharmacopoeia (Ph. Eur.) and the United States Pharmacopeia (USP) have been modified to reflect and complement ICH Q3D, providing details on the analytical methods to be used. In those chapters (Ph. Eur. 2.4.20., USP <233>), it is stated that for the quantification of elemental impurities, certified reference materials (CRM) from a national metrology institute (NMI) or reference materials that are traceable to the CRM of an NMI should be used.
The Ph. Eur. has so far implemented elemental impurity standards of this type for the four most important elemental impurities i.e. those corresponding to ICH Q3D Class 1: lead, cadmium, mercury and arsenic.
The poster provides details on the development of those four reference standards, which was undertaken in partnership with a major institute accredited CRM producer (JRC, European Commission), and a national metrology institute (BAM and PTB, Germany), and a Designated Institute and accredited CRM producer (BAM, Germany). The reference standards were established and characterised according to rigorous metrological principles and are supplied with extended supporting information as required for the intended use.
After successful completion of the project, the four reference standards have been added to the Ph.Eur. catalogue and are in distribution. It is expected that another three elemental impurity standards will be implemented and made available to users within the next three years.