A robust analytical method for simultaneous quantification of 13 low-molecular-weight N-Nitrosamines in various pharmaceuticals based on solid phase extraction and liquid chromatography coupled to high-resolution mass spectrometry.

Recently, the potentially highly carcinogenic N-nitrosamines (NAs) have become the focus of pharmaceutical regulatory authorities, the pharmaceutical industry and researchers because trace amounts have been detected in some drug products (DPs), resulting in drug supply shortages. In the absence of sufficient analytical methods for the determination of multiple regulated low-molecular-weight NAs in various DPs, a robust, selective, sensitive and accurate method based on sample preparation by solid phase extraction, followed by liquid chromatography high-resolution mass spectrometry for the simultaneous analysis of 13 regulated low-molecular-weight NAs was developed. The best results for the cleanup were obtained using Strata X-C SPE cartridge. The proposed method was successfully validated according to the USP general chapter 〈1469〉, demonstrating its excellent linearity, accuracy and precision in wide analytical ranges, adjusted to NAs acceptable intake limits. The achieved limits of quantitation correspond to 30 % or less of the acceptable intake limits. The developed analytical method was applied to 16 commercially available DPs containing one to three active pharmaceutical ingredients with different physicochemical properties. Only N-Nitrosodimethylamine was detected in DPs containing ranitidine at levels exceeding the regulatory AI limits by 37.6 - 57.4-fold. In addition, the robustness of the method was confirmed on a considerable number of DPs containing different active ingredients, demonstrating the suitability of the analytical method for routine quality control of different DPs, thus mitigate the risk to human health.

Stability-Indicating Analytical Approach for Stability Evaluation of Lactoferrin.

Lactoferrin is a multifunctional iron-binding glycoprotein in milk. Due to its potential for the treatment of various diseases, interest in products containing lactoferrin is increasing. However, as a protein, it is prone to degradation, which critically affects the quality of products. Therefore, the main purpose of our work was to develop a stability-indicating analytical approach for stability evaluation of lactoferrin. We were focused on two complementary methods: reversed-phase and size-exclusion chromatography. The stability-indicating nature of the selected methods was confirmed. They were successfully validated by following the ICH guidelines and applied to preliminary lactoferrin stability studies. Up to three degradation products, as well as aggregates and fragments of lactoferrin, were detected in various samples using complementary reversed-phase and size-exclusion chromatographic methods. The analytical approach was additionally extended with three spectroscopic techniques (absorbance, intrinsic fluorescence, and bicinchoninic acid method), which may provide valuable complementary information in some cases. The presented analytical approach allows the stability evaluation of lactoferrin in various samples, including the ability to detect differences in its degradation mechanisms. Furthermore, it has the potential to be used for the quality control of products containing lactoferrin.