All agencies have issued varying guidances for the approval of recombinant, biosimilars of biopharmaceuticals. However, their impact or meaning is in our understanding and that all submittals are considered on a case-by-case basis.
In this article, we discuss the use of CE-MS (sheath flow interface) for analysis of intact proteins as well as of protein digests. We discuss the unique aspects that the user needs to be aware of while testing biotherapeutics versus small molecule drugs. We also highlight that the optimization of CE and MS parameters together result in the creation of a more robust and reproducible protein analysis approach. Finally, we list some of the most common errors that are likely to occur during CE-MS analysis and suggest ways to overcome them.