Development and validation of a selective marker-based quantification of polysorbate 20 in biopharmaceutical formulations using UPLC QDa detection.

Polysorbates are widely used as non-ionic surfactant in biopharmaceutical formulations. Recently, the degradation of polysorbate moved into the focus of attention, because in several published studies it was described, that stability issues in polysorbate containing formulations were observed leading to the formation and appearance of sub-visible and visible particles. For this reason, monitoring of polysorbate and its degradation products is of importance throughout the development of parenterals. The aim of the study was to develop a method for the selective marker-based quantification of adequate polysorbate 20 components of interest without the need to apply derivatization or complex detection techniques. A single quadrupole mass (QDa) detector was used coupled to an ultra-high performance liquid chromatography (UPLC) system. Method development was based on a reversed phase-high performance liquid chromatography assay coupled to a charged aerosol detector (RP-HPLC CAD). Instead of a charged aerosol detector (CAD) a QDa detector was used in order to significantly improve the selectivity. The focus of this study is the development of the QDa based method for the analysis of polysorbate 20. Modifications of the mobile phase and the type of chromatography column allowed the separation of several components of polysorbate 20 from polar non-esterified to apolar higher order species. In addition, a multitude of components could be quantified by their individual m/z values. The peak assignment identified 676 compounds which originated from polysorbate 20. Some of these were selected and defined as marker components. It was shown that the developed method is capable to determine polysorbate 20 in different biopharmaceutical formulations. The proposed assay is based on a smart sample preparation as well as a unique calibration procedure that make the determination of several selected components achievable. Furthermore, it was successfully demonstrated that the analytical procedure is valid to reliably quantify several polysorbate 20 components at its 100% level (corresponds to 0.4 mg/mL intact polysorbate 20) and even at lower concentrations that occur e.g. in case of polysorbate 20 degradation. In conclusion, the method is beneficial to determine selected polysorbate 20 species during formulation development of biopharmaceuticals as well as during stability testing and trouble shooting.