samedan logo
 
 
 
spacer
home > ebr > autumn 2011 > at your disposal
PUBLICATIONS
European Biopharmaceutical Review

At Your Disposal

The disposable biomanufacturing industry has grown exponentially over the past decade, and it continues to revolutionise how biotherapeutics are manufactured today.

The advantages of disposable over traditional manufacturing approaches are well-known (see Figure 1). The ability to simply dispose of product-exposed process equipment and the decreased need for lengthy, cumbersome cleaning and validation procedures and cleaning CIP/SIP infrastructure has led to faster and more effi cient product change-over, decreased operating costs and increased facility throughput. Additionally, the use of disposable equipment signifi cantly reduces the risk of environmental or product cross-contamination and it is thus a safer alternative over-traditional biomanufacturing approaches.

These key advantages, combined with signifi cant improvements in titres, have decreased the demand for large fi xed steel-tank bioreactors. This trend has pushed the biomanufacturing industry into an ever-increasing acceptance of the disposable approach. Obviating the need for cleaning infrastructure and large fi xed assets means facilities can be built with a focus on multi-product fl exibility, effi ciency and process portability. A growing number of disposable products and vendors are available, particularly disposable bioreactors, buffer storage and fi ltration solutions, and while new downstream purifi cation single-use approaches are still needed, some major advances are on the horizon.

Benefits of Disposable Biomanufacturing

Disposable biomanufacturing technologies are increasingly being implemented by manufacturers. The primary reasons for this include decreased cleaning, reduced facility and equipment investments, shorter facility lead time, faster change-overs, and decreased risk of product contamination (see Figure 2) (1).

Facility Build Cost and Time Savings

The cost and time to build a traditional stainless-steel based biomanufacturing facility can be signifi cant. Stainless steel facilities need to be equipped with a costly infrastructure (for example clean steam, clean-in-place (CIP), water-forinjection (WFI), and air-handling systems) as well as capital equipment such as stainless steel bioreactors, liquid mixing and storage tanks, and column housings. Incorporating disposables into the design of a biomanufacturing facility can obviate the need for some of this, signifi cantly decreasing the costs of the facility and the time it takes to bring one online.

Facility/Product Change-Over

Typical cleaning protocols involve autoclaving, steam, chemicals and associated batch records, all of which must be completed between products and batches as part of the change-over process, which can take many days. On the other hand, disposable bags, tubing, fi lters and other product-contacting materials come pre-sterilised. Incorporating these into a biomanufacturing facility allows the avoidance of much of the traditional cleaning process. This can have a signifi cant effect on decreasing the change-over effort, cost and time between batches, which can increase the productivity of the facility.

Cleaning and Validation

Cleaning validation is a complex and time-consuming process. All productcontacting process equipment must be thoroughly cleaned using a variety of procedures (for example detergents, chemicals, steam and heat) and then thoroughly rinsed to remove any cleaning residuals. The process equipment cleaning process must be validated through sampling of rinses and swabs to confi rm the elimination of sources of potential contamination. In addition, the SIP/CIP and other cleaning equipment itself must also be validated.

The use of disposables provides a ready source of sterile productcontacting process equipment removing the need for much of this cleaning and validation and shortening the facility change-over process. Furthermore, although the bags and other product-contacting disposable materials will need to be validated, much of this work is already done by the vendors themselves. Taken together, a disposable biomanufacturing facility can greatly simplify the cleaning validation process and change-over procedures that occur between products, which can significantly increase its batch output.

Contamination

One of the most important advantages of using disposable bioprocess equipment is that it provides a decreased risk of contamination – one of the top reasons for batch failure and a significant safety concern (1). Steel-tank bioreactors and holding tanks along with other multi-product contacting equipment carry the risk that previously manufactured product might crosscontaminate the next, particularly when transitioning between a high-yielding or concentrated product to a low one. The implementation of single-use equipment ensures that the risk of crosscontamination is eliminated. Additionally, the pre-sterilised disposable equipment results in significant reduction in possible microbial contamination.

Flexibility

A significant advantage for a biomanufacturer looking to build a multi-product facility from the ground up who is therefore able to design and integrate disposables into their systems, is the flexibility they offer. The decreased amount of infrastructure and room for open space allows one to design the facility in a flexible manner. Much of today’s equipment including disposable bioreactors is portable. Consequently bioreactors, chromatography skids and other equipment can be transported in and out as needed for different products. Furthermore, disposable bioreactors can be added in parallel fashion to allow for easy scale-up without having the need to validate at multiple volumes. A process can be validated at a single volume and additional bioreactors of the same scale added as needed. Transferring a process from one facility to another is also much easier for a process using disposable equipment. A product developer can outsource their early phase manufacturing without the cost commitment of building a facility until later in clinical development when the risk of failure is lower, since the lead time for a disposable facility is much shorter.

Single-Use Challenges

Despite the many clear operational advantages of disposables, there are issues specific to them which must be considered. The disposables themselves can be a significant cost element, depending on the scale and specific equipment used. Furthermore, given that single-use equipment is just that, single-use, proper disposal of the waste generated must be given some deliberation, specifically around product containment if the product is hazardous, and around the environmental impact of generating the additional waste, which is an increasingly important consideration.

Additionally, product safety and quality are significant concerns due to the potential for extractable and leachable contaminants in the final product from the materials used in disposable equipment. Bio-Process Systems Alliance (BPSA) is a group that was created in 2005 by the industry to address these types of issues and to recommend best practices for single-use implemenatation, extractable/ leachable testing, and disposal (2-4).

Single-Use Equipment and Technology

In a typical biomanufacturing process, illustrated in Figure 3, there are many unit steps and equipment for each, which work in series and must be integrated. One of the earliest implementations of disposables is the storage bags for holding media, buffers and other solutions that replace large fixed stainless steel vessels. Many vendors now offer systems for liquid storage, which include the bags and stackable holders or totes, along with disposable tubing, clamps, connectors and the ability to sterile weld connections. These systems offer a significant advance over having to autoclave the equipment then make these connections within a sterile environment.

Bioreactors

Disposable stirred-tank bioreactors are currently being offered by several vendors at scales ranging from 10L to 2,000L, which have the standard cylindrical shape of steel-tank bioreactors. They appear to produce product comparable to that from traditional steel-tank bioreactors up to 1,000L (5). Most of these systems are used for production of mammalian cell culture-based products. Their use is less prevalent in microbial-based products due to the high oxygen demand and heat outputs of bacterial and yeast systems, which most of the current systems are not able to handle.

One of the key issues around disposable bioreactors has been the ability to scale-up the cell culture process from the bench to production scale. In June of this year however, Xcellerex launched a 10L disposable bioreactor which joins the existing XDR collection of bioreactors ranging up to 2,000L (6). All of the XDR bioreactors share the same design, vessel geometry, control instrumentation and which should allow more linear scale-up of processes in the future and is an indication of where the disposable bioreactor marketplace is heading.

Filtration

Another area of disposable biomanufacturing technology that has made major progress during recent years is in the area of filtration. Depth filters for clarification of harvest material and other normal flow filtration (NFF) filters along with tangential flow filtration (TFF) filters for ultrafiltration and diafiltration are available as single-use cassettes, where all product contact surfaces are disposable and there is no product contact with endplates or the process skid. Issues still to be resolved with these systems relate to integration and compatibility of the connectors and that disposable tubing in general is not able to handle high-pressures and flow-rates needed for some filtration unit steps. Until recently, another challenge was that for depth filtration, scales greater than 1,000L were not available. Now, however, several vendors offer disposable filter systems at large scales (for example Millipore Millistak+® Pod, CUNO® Zeta Plus™, Pall® Life Sciences Stax™).

Chromatography

Chromatography has been the most challenging bio-processing step in which to incorporate single-use technology thus far. However, much effort has been made into this area over the last few years and consequently, several options now exist. Pre-packed disposable chromatography columns are now available, such as GE’s ReadyToProcess™ and GoPure™ Prepacked chromatography columns from Applied Biosystems®, ranging up to 20L for the former for early phase clinical production. These come pre-packed, qualified and sanitised. However, given the cost of resins and the fact that 20L is currently the largest volume option available, single-use chromatography may not be a viable option for many. Consequently, alternative strategies to chromatography are also being pursued.

Continuous or Simulated Moving Bed chromatography is an old technology originally developed in the 1950s for the petrochemical industry that has just recently been applied to bioprocessing. The technology involves a group of smaller chromatography columns which replace a single large column. Tarpon BioSMB™ systems have been developed for protein purifi cation which involves countercurrent processing. This type of technology allows the saturation of the chromatography media above its dynamic binding capacity by eliminating idle zones. In this way, one can use the same basic process (for example media and buffer conditions) as employed for batch chromatography, but with signifi cant increases in productivity, and corresponding decreases in processing time, volumes of media used (inversely proportionate to the number of columns used) and buffer requirements.

Purification Techniques

Another advance in disposable purifi cation technology is a monolithbased purifi cation platform, consisting of a solid, homogenous, porous support having uniform sized channels mostly used for large-scale purifi cation of live viral vaccines. However, more recently companies like BIA have developed monoliths for purifying proteins such as antibodies, which are thought to offer superior fl ow rates, binding capacity and separation resolution (7).

Of all the disposable technologies over the past fi ve years, implementation of disposable membrane adsorbers into biomanufacturing processes has been growing at the fastest rate (1). Traditionally, membrane adsorbers have been used in the fl ow-through mode, whereby impurities (for example DNA, endotoxin, virus and so on) bind to the membrane while the protein of interest fl ows-through. Capture membranes have been developed, but typically these have lower binding capacity compared with chromatography resins.

Recently, potentially enabling membrane technologies have been advanced. Electrospun cellulose acetate nanofi bers have been developed, which have either been modifi ed to allow for direct protein adsorption, or have been tethered with nanofibers capable of protein-binding through ion-exchange, hydrophobic interaction, or affi nity interactions (8,9). These authors reported much higher binding capacities and permeabilities, and reduced residence times as compared to traditional packed bed resins. In another recently launched technology, Natrix Separations has developed a capture membrane adsorber made up of a porous support membrane whose pores are fi lled with a macroporous hydrogel dense enough that liquid passing through the membrane is forced through the macropores. The specifi c chemistry of the hydrogel determines the specifi c product which is captured. The binding capacity and allowable fl ow rate of the membrane is superior to that of chromatography resin partly due to the large surface area for binding that the membrane provides.

Conclusion

The road to a fully disposable bio-manufacturing process from bench to commercial production is on the horizon. With the recent advances of disposables in upstream and downstream processing, many options now exist at larger scale than ever before. Although challenges still remain, especially in the realm of purifi cation, the industry continues to push for new and evolving technologies.

References

  1. 8th Annual Report and Survey of Biopharmaceutical Manufacturing, BioPlan Associates, 2011
  2. Advancing Single-Use Worldwide, Bio-Process Systems Alliance, www.bpsalliance.org
  3. Extractables and Leachables Subcommittee of the Bio-Process Systems Alliance, Recommendations for extractables and leachables testing Part 1: Introduction, regulatory issues, and risk assessment, BioProcess International 5(11): pp36-44, 2007 
  4. Extractables and Leachables Subcommittee of the Bio-Process Systems Alliance, Recommendations for extractables and leachables testing part 2: Executing a program, BioProcess International 6(1): pp44-62, 2008
  5. Paul Smelko J et al, Performance of high intensity fed-batch mammalian cell cultures in disposable bioreactor systems, Biotechnol Prog, 2011
  6. Xcellerex introduces 10 Liter XDR Single-Use Bioreactor, www.xcellerex. com/pdf/Xcellerex_XDR10.pdf, 2011
  7. Prasanna RR and Vijayalakshmi MA, Characterization of metal chelate methacrylate monolithic disk for purifi cation of polyclonal and monoclonal immunoglobulin, G J Chromatogr A 1217(23): pp3,660-3667, 2010
  8. Zhang L, Menkhaus TJ and Fong H, Fabrication and bioseparation studies of adsorptive membranes/felts made from electrospun cellulose acetate nanofi bers, Journal of Membrane Science 319: pp176-184, 2008
  9. Menkhaus TJ et al, Electrospun nanofi ber membranes surface functionalized with 3-dimensional nanolayers as an innovative adsorption medium with ultra-high capacity and throughput, Chem Commun (Camb) 46(21): pp3,720-3,722, 2010

Read full article from PDF >>

Rate this article You must be a member of the site to make a vote.  
Average rating:
0
     

There are no comments in regards to this article.

spacer
Nicole O’Brien is the Director of Proposals and New Technology at Gallus BioPharmaceuticals in St Louis, MO. Nicole received her undergraduate degree from the University of California, San Diego and her PhD in Cell and Molecular Biology from San Diego State University and University of California, San Diego, jointly. She has been involved in business development for contract manufacturing organisations for the last several years serving in technical and sales operations roles. She began her career studying the role of sphingolipids in cardiomyopathies and oncology at LPath Therapeutics. From there she joined Biogen Idec as a scientist in their molecular oncology department where she managed several early stage oncology research projects. Email: nicole.obrien@gallusbiopharma.com
spacer
Nicole O’Brien
spacer
spacer
Print this page
Send to a friend
Privacy statement
News and Press Releases

SEKISUI XenoTech Receives New US Patent for a Method to Evaluate Xenobiotics as Immune-Modulators of Drug Transport and Metabolism in Hepatocytes

Kansas City, KS- SEKISUI XenoTech has been awarded US patent # 10,648,968 “In vitro test system to evaluate xenobiotics as immune-modulators of drug transport and metabolism in human hepatocytes.”
More info >>

White Papers

RSSL introduces same-day mycoplasma testing service in UK

RSSL

Reading Scientific Services Ltd (RSSL), a leading provider of scientific and technical solutions to the global biopharmaceutical, pharmaceutical, and biopharmaceutical sectors, has introduced the United Kingdom’s first same-day mycoplasma testing service for manufacturers of biologic medicines.
More info >>

 
Industry Events

12th World Meeting on Pharmaceutics, Biopharmaceutics and Pharmaceutical Technology

8-11 February 2021, Vienna, Austria

In continuation of the very successful scientific meetings in Budapest, Paris, Berlin, Florence, Geneva, Barcelona, Malta, Istanbul, Lisbon, Glasgow and Granada, the 12th PBP World will be held in Vienna from 8-11 Feb 2021. This every two year held conference has gained an ever increasing impact among the pharmaceutical scientists: With up to 1000 submitted abstracts and about 1300 participants it has become a well-established major meeting, attracting scientists from all over the world.
More info >>

 

 

©2000-2011 Samedan Ltd.
Add to favourites

Print this page

Send to a friend
Privacy statement