For the past few years, at least, discussions about bioprocessing often include the transition to continuous processing. More than one expert will say that continuous methods are the likely future of bioprocessing and many of the necessary parts are in place, but is this transition really happening?

Vendors are counting on it, already making and selling single-use tubing and filters, plus plastic bioreactor bags of many sizes. One market report even forecasts that single-use bioprocessing will bring in $33 billion a year by 2027.

Yet, the industry overall is not making the transition so far. In 2020, Ashish Kumar, PhD, assistant professor of pharmaceutical engineering at Ghent University in Belgium, and his colleagues wrote: “Despite a number of clearly identified benefits compared to traditional batch processes, continuous bioprocessing is still not widely adopted for commercial manufacturing.”

The disconnect between this great idea—promising faster, cheaper, and higher quality bioprocessing—and the lack of industrial penetration arises from a crucial problem: the transition is tricky. First, although the terms single-use and continuous seem nearly synonymous in bioprocessing discussions, there’s more than one way to go continuous. It could be single-use or sticking with stainless steel.

“In a world where people are worried about grocery bags and disposable cups, justifying an industry’s transition from multi-use stainless steel to disposable plastic adds another dimension of concern,” Kumar and his colleagues noted.

Plus, James DeKloe, PhD, director and founder of the industrial biotechnology program at Solano College in California, points out: “The plastic used in single use cannot be recycled. Without doubt this technology dramatically increases the solid waste that currently goes to landfill.”

Beyond complicated choices in devices and what goes to; landfills, pharmaceutical companies face challenges with personnel. In a recent virtual roundtable, Christine Moore, PhD, executive director and global head of CMC (chemistry, manufacturing and control) policy at Merck, noted that the manufacturing sector lacks the workforce to switch to some forms of continuous processing.

So, despite the upsides to continuous approaches, the industry must resolve some of the downsides before rolling out the switch in a big way. In short, that’s going to take some time.