According to Kent Iverson, a biotech consultant based in the San Francisco area, it might be time for the industry to “take a step back and look critically at the pros and cons of single use as opposed to reusable bioprocessing technologies. I think the bioprocessing industry as a whole embraces single use without acknowledgement of its shortcomings.”
Iverson believes that single-use manufacturing may be more expensive than reusable operations when capital costs are appropriately amortized. Single-use bioreactor technology is not as scalable as stainless-steel bioreactor technology, nor is it amenable to fully automated operations. Disposable components require a greater amount of transport into and out of production areas, as well as manual set up and take down, and this creates a higher floor of labor resource and facility space needed per unit of production. Single-use technologies are also limited in terms of scale and capacity of clarification steps, whereas the limitations for reusable technologies such as centrifugation are cost, space, and efficiency.
The sustainability of single-use components is another important aspect to consider. “For instance, water consumption is significant in a production operation based on stainless steel/reusable equipment. However, this is also true for single use; 24 gallons of H20 are required to manufacture 1 lb of some plastic polymers. Whereas reusable equipment produces waste materials, single-use operations produce both liquid and solid waste that often end up in a landfill.”
Iverson mentioned Thermo Fisher as a company that has developed innovative programs for use of its used single-use components. The company recently joined the Healthcare Plastics Recycling Council (HPRC), which is currently engaged in multiple initiatives aimed at enabling recycling of healthcare plastics.
Toxicity is another environmental cost that can come with synthetic polymers. For example, a regulatory process is underway to restrict use of Triton X-100, a detergent used in the production of some biopharmaceuticals. “I see the green plastics industry responding to regulatory guidelines that will call for substitutes in the near future,” Iverson stated. Curing agents used to make films for single-use products are in some cases bioreactive, and these substances will continue to be scrutinized for toxicity.
Regulatory agencies outside the U.S. may also carry out evaluations that can affect the use of various chemicals in the production of biologics. These include the REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) program of the European Union, designed for the protection of human health and the environment from chemical hazards, while promoting alternative methods for their evaluation and approval.
“Single-use technologies are ideal for certain types of operational situations, such as those requiring small scale, multiple train production (some cell therapy products, for example),” Iverson said. “Within the spectrum of bioproduction scenarios, there is a point at which larger scale and more complete automation of unit process steps make reusable technologies a better choice. In my opinion, that dividing line occurs at a lower level of production capacity than most biopharma companies recognize.”