The Evolution from Fixed to Single-Use Systems

An overview of applications for disposable components and important property considerations. This article is part of a special issue on Single-Use Technologies.
Nov 02, 2011


Image courtesy of the authors
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.

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.