Highly Characterized - Poorly Characterized

 

In addition to the myriad of cleaning processes which must be evaluated, there are additional
difficulties: appropriate limits for active agents must be selected; this limit might be based
upon a not yet identified therapeutic dose.

Alternatively, using the lowest dose, or considering using the worst case might save time on scale up, provided that the appropriate
assays for these levels have been developed and validated.

Other difficulties include the requirement that appropriate analytical methods must be developed for all formulations.
Clearly, while the validation of cleaning is a difficult task in a production facility, the
unknowns inherent in clinical product manufacturing, where the product is poorly
characterized, make the task even more challenging.

Other areas where products may be poorly characterized include bioprocesses and syntheses
where vast numbers of related molecules may be formed, in addition to the primary product.
While there are generally requirements that all of these potential "contaminants" developed
during the manufacturing process be identified, these materials may not be characterized well
enough to have specific, low-level assays developed for each of them.

The establishment of appropriate limits for each of these substances is equally complicated and may not be feasible.