Recombinant proteins as active ingredients of biotechnologically produced drugs (biopharmaceuticals) are produced in multi-stage, complex manufacturing processes: In an upstream processing stage, cells containing the genetic information in functional form for the desired protein are cultured in bioreactors and finally stimulated to produce (express) the target protein. The active ingredient is then extracted, purified and concentrated in downstream processing. In addition, various procedures are used to ensure security against viruses and infectious agents. As an alternative to the established cell lines, transgenic animals and plants can also be used for the production of recombinant therapeutic proteins.

In contrast to chemically synthesized preparations, recombinant proteins are characterized by a complex molecular structure and a certain microheterogeneity in their structure. Therefore, for the characterisation of these substances, several analytical methods are always necessary/required, each of which can cover different aspects (e.g. structure, post-translational modifications, product-specific variants and impurities, biological activity).

The official approval of biological medicinal products with recombinant proteins as active ingredients takes place in the EEA within the framework of central approval procedures, which are coordinated by the European Medicines Agency (EMA). In these approval procedures, two member states are designated as rapporteurs and co-rapporteurs, who prepare the expert opinions, which are later discussed and finalized at the EMA in joint meetings of all member states.