For many years, "blockbuster" drugs have made fixed systems the most pragmatic choice for manufacturing high volumes to meet
high demand. Fixed systems rely heavily on stainless steel for piping, valves, tanks, and fittings because the parts needed
are rigid and fixed in nature. Steel components can be manufactured with a variety of surface finishes, are sterilizable using
most sanitizing medium, and can withstand high temperature. Production runs in fixed systems tend to be long with infrequent
changeover. For the above reasons, and because of the riskadverse culture that is synonymous with drug manufacturing and engineering,
stainless steel has been the predominant material in biopharmaceutical manufacturing.
Image courtesy of the authors
This thinking began to evolve with the advent of single-use systems (SUS), most commonly referred to as "disposables." A new
mindset and technical platform was introduced to meet the changing industry needs presented by "personalized" large-molecule
drugs. Initial SUS processes were deployed by manufacturers in response to the need for the low-volume production of vaccines
in high concentration (Merck) and to meet hormone medication commercialization (Amgen) in a relatively short period of time
(1). Fixed stainless-steel systems require extensive downtime because the process needs to be revalidated and sterilized after
each use. Disposable process technology, on the other hand, utilizes fewer parts and eliminates the costly need to revalidate;
the system can be used once before the prevalidated components are replaced for a fast changeover to a new vaccine or drug.
Factors favoring the fundamental shift to SUS are:
- Reduced R&D costs compared with using a high volume fixed system as part of the research line.
- Decreased time to market for a specific medicine, which can be tailored for smaller volume use.
- Rapid setup and regional deployment to meet drug needs worldwide.
- Ability to manufacture many products in the same facility with no risk of cross-contamination.
- Minimal expansion cost through drug development and scale up.
- Lower utility costs in cleaning and system revalidation.