Nowadays, therapeutic antibodies are the major and fastest growing class of biotherapeuticals. Since their invention, they are continuously developed to improve structural and functional... Show moreNowadays, therapeutic antibodies are the major and fastest growing class of biotherapeuticals. Since their invention, they are continuously developed to improve structural and functional characteristics. The high complexity of recently generated antibody derivatives, with various modifications induced during the manufacturing process itself leads to many proteoform variants of the desired product. These proteoforms can potentially exhibit altered activity. Therefore, an adequate characterization of the proteoforms, the assessment of their impact and careful monitoring of critical species is indispensable in order to guarantee effective and safe biopharmaceuticals. As the landscape of next-generation Ab formats continuously evolves, it is likewise of great importance to further develop appropriate analytical methods for their thorough attribute analysis. Hence, the focus of the research performed in this thesis is the development of multi-level approaches for the in-depth, primarily MS-based characterization of biopharmaceuticals to overcome the present restrictions and challenges arising e.g. by the implementation of complex Ab formats. Show less
Particles are omnipresent in biopharmaceutical products. In protein-based therapeutics such particles are generally associated with impurities, either derived from the drug product itself (e.g.... Show moreParticles are omnipresent in biopharmaceutical products. In protein-based therapeutics such particles are generally associated with impurities, either derived from the drug product itself (e.g. protein aggregates), or from extrinsic contaminations (e.g. cellulose fibers). These impurities can affect product stability, as well as cause adverse effects once introduced into the human body. Particulate impurities are present over a wide range of sizes (from nanometers to millimeters) making them difficult to characterize by using a single method.Novel drug products may also contain particles that act as the active pharmaceutical ingredient (e.g., living cells) or a drug delivery vehicle (e.g., lipid nanoparticles). Unwanted immunotoxicity and inconsistent in vivo functionality can result from particle instability and aggregate formation. Therefore, the efficacy and safety of these therapeutics is dependent on the particle composition, quantity and size distribution.Consequently, well-established methods are required to quantify and characterize particles in the submicron- and micron-size ranges. In this thesis, we developed new approaches which allow for comprehensive characterization of the particle populations present in biopharmaceutical products, both as impurities or as API. Furthermore, the performed work focused on comparing different particle characterization techniques to allow a better understanding of the limitations and strengths of each method applied. Show less
