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Electrical semiconductor characterization
Luminescence dating, research, dosimetry and more
Free radical measurements in life science and biomedical applications
Our benchtop MiniScope (MS 5000) ESR spectrometer is a research grade device with sensitivity and reliability for demanding...
Industry standard for evaluating irradiation doses on alanine tablets
Nitric oxide measurement, reactive oxygen species, oxidative stress, radical generating systems, photo dynamic therapy
Antioxidative features of foodstuff, radicals on foodstuff, radiation-induced radicals
Analysis of chemical structure of paramagnetic centers and their orientation within a crystal
Bioinorganic transition metal compounds, fenton chemistry, effect of heavy metal ions on livving tissue
Variety of free radicals in environmental applications can be evaluated by EPR spectroscopy
Living polymers, nitroxide quantification, radicals in varnish, UV stability of scratch resistant varnish
Quality control of pharmaceuticals and impurity profiling
ESRStudio is a dynamic and user friendly software for ESR measurements with some of the most modern and fluent workflow based...
Magnettech GmbH was founded in 1991 by the members of the department of "Centre for Construction of Scientific Devices"...
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Non-invasive detection of impurities, Quality Control of pharmaceuticals, monitoring degradation
ESR provides a simple and fast method to detect degradation of pharmaceutical products. The impact of sterilization process, stress testing and new reaction mechanisms on the degree of purity is monitored by MS 5000.
Since the pharmaceutical development and production includes more and more drug formulations with a controlled release of the effective substance, there will be a growing demand for biodegradable polymers. If these products are destined for parental use they have to be sterilized. Heat and steam cannot be applied because they certainly damage these substances, leaving only γ-radiation as an appropriate procedure. However, this method of sterilization could induce free radicals. The generation of radicals during this kind of treatment has been studied with the MiniScope.
Three different biodegradable polymer compositions (all PLGA polyester) have been investigated applying 25 kGy irradiation of γ-rays per sample.
scan time = 60 s
sweep range = 15 mT
frequency ≈ 9.4 GHz (X-band)
In the first preparation any radical induced by the y-radiation will neutralise the spin label and thus decrease its ESR signal by pairing electrons (Fig. 1, 25 kGy). Radiation induced radicals cause spin pairing with the spin label (TEMPOL) and thus decrease the ESR-signal (see Fig. 1)
In the second one the short-lived radicals generated in the polyester will be trapped by the spin trap. Thus, the spectrum of the spin adduct (spin trap plus unpaired electron) appears (see Fig. 2)
In the third case, the ESR spectrum of alanine radical will show up (Fig. 3). This radical is long-term stable. Since all these experiments have been performed in a dry matrix, the nitroxyl radicals (Fig. 1 and Fig. 2) show the typical anisotropic ESR spectra of immobilised molecules.
Till Hauenschild, Joerg Reichenwallner, Volker Enkelmann, Dariush Hinderberger (2016): Characterizing Active Pharmaceutical Ingredient Binding to Human Serum Albumin by Spin-Labeling and EPR Spectroscopy. Chemistry, A European Journal 22, 12825 – 12838
Fabienne Payrot, Catherine Grillon, Catherine Vergely, Luc Rochette, Claire Ducrocq (2005): Pharmacokinetics of 1-nitrosomelatonin and detection by EPR using iron dithiocarbamate complex in mice. Biochemical Journal 387, 473 – 478