Biology Reference
In-Depth Information
consists of agarose or acrylic beads of defined pore sizes. Proteins too large to
penetrate the pores are excluded from the interior volume of the beads and
have a shorter elution path through the column (hence they elute sooner).
Smaller proteins either partially or completely penetrate the pores, resulting in
a longer elution path and longer elution times.
Viral clearance
If rHuEPO is made in mammalian cells, the ability to remove theoretical
endogenous or adventitious viruses from the product must be shown. Because
virus titers are well below the level of detection, bench-scale studies are done
in which different types of model viruses are deliberately added to process
streams to demonstrate the ability of the process to remove viruses. Usually
several types of viruses are used, including enveloped and non-enveloped
viruses.
Dosage form (drug product) manufacturing
In general, dosage form manufacturing of rHuEPO, as with all recombinant
protein products, is governed by national governmental regulatory agencies to
ensure that biologic production facilities adhere to sound quality control and
current GMP. Facilities that produce rHuEPO are routinely audited and
inspected to ensure compliance and patient safety. In the United States, bio-
logic production for parenteral applications is governed by the Food and Drug
Administration (FDA CBER/CDER); regulations are covered under section 21
of the
Code of Federal Regulations
Parts 210 and 211. These regulations dif-
fer slightly from country to country. All manufacturing plants and processes
are validated and filed with the FDA (or regional authority) before marketing
approval is given. All operations are conducted in an aseptic, temperature-con-
trolled, highly monitored environment, with final filling operations done under
conditions that typically allow only 100 particle counts/cubic foot of air in the
filing operation suite. For dosage form/drug product manufacturing, maintain-
ing validated processes, quality control, and aseptic conditions are critical to
patient safety and product integrity.
In addition to regulatory compliance, a primary concern for recombinant
proteins, and in particular rHuEPO, is the maintenance of product integrity by
minimizing physical or chemical degradation. Product integrity is maintained
from the bulk stage through the final dosage form by adjusting process param-
eters and the composition of the final formulation. To mitigate process
impacts, rHuEPO is formulated in solutions that often contain human serum
albumin or polysorbate that act as a protector against surface adsorption, sur-
face denaturization, shear forces, chemical degradants, and other deleterious
factors. Because of the relatively low concentrations of rHuEPO used clinical-
