A Novel Approach for the Assessment of Insulin Potency by Glycemic Monitoring of an Insulin-Dependent Human Cell Line

Delbeck, Sven; Krolinski, Adrian; Dederich, Yannick; Stoppelkamp, Sandra; Heise, H. M.

doi:10.1177/1932296819895541

Cited by 4 publications

(3 citation statements)

References 3 publications

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“…15 , 32 , 33 Recently, a replacement of the US pharmacopoeia rabbit blood sugar method by an in vitro cell test has been suggested by us. 16 The European Pharmacopeia does not require an in vivo bioidentity test, and their quality assurance is solely based on a HPLC method quantifying total insulin, but not necessarily discriminating from, e.g., misfolded fractions.…”

Section: Discussionmentioning

confidence: 99%

“… 11 – 13 An innovative method, based on infrared attenuated total reflection (IR-ATR) spectroscopy of insulin dry-films, as prepared from microliter sample volumes, is a promising analytical tool for quantifying the degree of insulin degradation, which can most likely be correlated with a decrease in biological potency as measured by classical or novel insulin assays. 14 – 17 A systematic study has been carried out by us on the effect of different storage temperatures over a time period of up to three months with weekly spectroscopic measurements. By analyzing either specific shifts of the protein secondary structure sensitive absorption bands in the IR spectra or by band deconvolution, even small structural changes become detectable, especially within the spectral features calculated from second derivatives.…”

Section: Introductionmentioning

confidence: 99%

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Systematic stability testing of insulins as representative biopharmaceuticals using ATR FTIR-spectroscopy with focus on quality assurance

Delbeck

Heise

2021

J. Biomed. Opt.

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. Significance: Bioactive proteins represent the most important component class in biopharmaceutical products for therapeutic applications. Their production is most often biotechnologically realized by genetically engineered microorganisms. For the quality assurance of insulins as representatives of life-saving pharmaceuticals, analytical methods are required that allow more than total protein quantification in vials or batches. Chemical and physical factors such as unstable temperatures or shear rate exposure under storage can lead to misfolding, nucleation, and subsequent fibril forming of the insulins. The assumption is valid that these processes go parallel with a decrease in bioactivity. Aim: Infrared (IR) spectroscopy has been successfully utilized for secondary structure analysis in cases of protein misfolding and fibril formation. Approach: A reliable method for the quantification of the secondary structure changes has been developed using insulin dry-film Fourier-transform IR spectroscopy in combination with the attenuated total reflection (ATR) technique and subsequent data analyses such as band-shift determination, spectral band deconvolution, and principal component analysis. Results: A systematic study of insulin spectra was carried out on model insulin specimens, available either as original formulations or as hormones purified by ultrafiltration. Insulin specimens were stored at different temperatures, i.e., 0°C, 20°C, and 37°C, respectively, for up to three months. Weekly ATR-measurements allowed the monitoring of hormone secondary structure changes, which are supposed to be negatively correlated with insulin bioactivity. Conclusions: It could be shown that IR-ATR spectroscopy offers a fast and reliable analytical method for the determination of secondary structural changes within insulin molecules, as available in pharmaceutical insulin formulations and therefore challenges internationally established measurement techniques for quality control regarding time, costs, and effort of analysis.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Systematic stability testing of insulins as representative biopharmaceuticals using ATR FTIR-spectroscopy with focus on quality assurance

Delbeck

Heise

2021

J. Biomed. Opt.

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“…A promising alternative approach was recently presented by Delbeck et al, based on exploiting the insulin dependency of a human monocytic cell line under special culture monitoring conditions. 31 Results from such an assay should be further correlated with the “insulin misfolding degree” as determined by dry film IR spectroscopy.…”

Section: Discussionmentioning

confidence: 99%

Quality Assurance of Commercial Insulin Formulations: Novel Assay Using Infrared Spectroscopy

Delbeck

Heise

2020

J Diabetes Sci Technol

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Background: For insulins in commercial formulations, degradation can be observed within the certified shelf life when not stored at recommended conditions. Elevated temperatures and exposure to shear forces can cause changes in the secondary structure of the hormone, leading to a decrease in pharmaceutical potency. International pharmacopoeia recommendations for insulin quality monitoring assays mainly rely on liquid chromatography methods. These methods are unable to distinguish between active and inactive forms, both of which may exist in pharmaceutical insulins exposed to stress conditions. Method: Infrared attenuated total reflection spectroscopy has been used for the analysis of insulin dry film preparations using affordable instrumentation. This method can be applied to either formulated insulin specimens or pure insulins obtained by ultrafiltration. Such samples have been stored under different temperatures (0°C, 20°C, and 37°C), and degradation processes have been monitored up to a period of a few months. Results: By analyzing specific shifts of absorption bands in the infrared spectra, which are sensitive to the protein secondary structure, even small structural changes in the hormone become evident. Another option is amide I band deconvolution into individual bands, which can be attributed to secondary structure subunits that are part of the insulin tertiary structure. Conclusion: A novel and innovative method based on infrared attenuated total reflection spectroscopy of insulin dry films is a promising analytical tool for quantifying the degree of insulin degradation, as it provides information on indicating a decrease in biological potency. The established methods for insulin potency assays require animal testing or clamp experiments on people with diabetes.

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Thermal stability and storage of human insulin

Richter,

Bongaerts,

Metzendorf

2023

Cochrane Database of Systematic Reviews

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A Novel Approach for the Assessment of Insulin Potency by Glycemic Monitoring of an Insulin-Dependent Human Cell Line

Cited by 4 publications

References 3 publications

Systematic stability testing of insulins as representative biopharmaceuticals using ATR FTIR-spectroscopy with focus on quality assurance

Systematic stability testing of insulins as representative biopharmaceuticals using ATR FTIR-spectroscopy with focus on quality assurance

Quality Assurance of Commercial Insulin Formulations: Novel Assay Using Infrared Spectroscopy

Thermal stability and storage of human insulin

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