However, each expression system needs to be appropriately controlled. There is the potential for transmission of adventitious agents, bacteria, mycoplasma, fungi, viruses and transmissible spongiform encephalopathy (TSE) agents. As a result, there is the expressed need for in-process controls and validation to ensure safety of biological products.
A major aspect of proteins is stability. There are unique considerations for the stability of biologics. They are heat sensitive and susceptible to microbial contamination. There must be a controlled temperature during production, aseptic processing throughout, and the product cannot be terminally sterilized.
The pharmacokinetics (PK) of biologics are not well established. For example, if a firm is looking at the PK of a protein, there is not a definitive assay for what the molecule is in the serum; this can make it challenging to define pharmacokinetics. Metabolism is another example of the challenges associated with identifying the PK of a biologic.