Evolving Sterilization Methods
When viruses, bacteria, fungi, and other microbes were first discovered, they were not an immediate concern for scientists; their ability to cause illness was not yet recognized. Fast-forward a couple decades, however, and scientists were beginning to realize that germs cause disease. Systems that could kill these microbes became necessary. Steam sterilization was a forerunner in the evolution of sterilization methods; over the years, methods and options have evolved to include other alternatives. From food manufacturers to medical device manufacturers, modern industries depend on sterilization.
Pharma manufacturers are, undoubtedly, aware of sterilization’s significance. Proper sterilization processes are important for surfaces, such as pharmaceutical manufacturing equipment and packaging, as well as the pharmaceuticals themselves. Unlike other processes, such as sanitization, sterilization kills all forms of microbial life instead of simply reducing microbes to an acceptable level.
Pharma manufacturers depend on high-quality, reliable sterilization equipment, so that they can produce a high-quality product. To better understand current trends in sterilization for pharma manufacturers, Pharmaceutical Processing spoke with companies that offer sterilization equipment.
The Many Faces of Sterilization
Depending on the facility’s needs, sterilization methods vary. “Each of the various methods of sterilization has unique purpose and value depending on the application,” Bruce Anthenat, President of AWS Bio-Pharma Technologies, a company that offers several types of equipment for sterilizing and depyrogenation of glassware components, as well as materials used in the manufacturing process of injectable drugs, explains. “Sometimes it is possible to choose more than one method for a specific application, but generally the pluses and minuses of each process are evaluated, and the best method is chosen based on the process' pluses and minuses.”
Although other methods are more suitable for sensitive applications, steam sterilization, one of the earliest forms of sterilization, still comes out on top for many applications. “Steam sterilization is by far the most commonly used method of sterilization in the pharmaceutical industry,” says Dave Mitchell, Business Unit Manager in the Sterilization Systems group of Environmental Tectonics Corp., which offers steam and ethylene oxide (EtO) sterilizers, as well as field maintenance services, system refurbishment, utility engineering, and control system upgrades. “Steam is very inexpensive to create and the equipment costs are typically much less than alternative technologies,” he adds.
Dr. Paul Stewart, Director of Business Development for the Pharma & Biotech department of Telstar Life Sciences, a company that provides steam and super-heated water autoclaves, ethylene oxide sterilizers for device sterilization, depyrogenation ovens and autoclaves for bio-decontamination, a sterilization laboratory, and more, agrees: “For terminal sterilization of pharmaceutical products and for bio-decontamination of materials, steam sterilization is still the most widely used; it’s safe, low cost, and easily validated.” Stewart adds that, although steam is very popular, for processes such as “surface decontamination of isolators and other enclosures, techniques based on the use of a solution of hydrogen peroxide delivered in the form of a vapor are the most popular.”
Anthenat agrees. He explains that, although steam is perfect for some applications, “If an item to be sterilized is sensitive to heat, then a steam sterilization process would not be one of the best options."
Luckily for pharmaceutical manufacturers, we have come a long way from the days when steam was one of the only options available, and we now have various sterilization options for handling materials that cannot withstand steam’s high heat.
Single-Use Systems’ Impact
Single-use systems, which are becoming increasingly popular, are impacting sterilization trends. Anthenat says that “in single-use systems, the ‘change parts’ are typically pre-sterilized, so there is no need for sterilization before use.” This pre-sterilization “reduces the limits on holding time after sterilization, the amount of validation to support the in-house sterilization, and the associated holding time of the items,” he explains.
“From a manufacturing perspective, the use of pre-sterilized materials is resulting in increased use of rapid surface sterilization during transfer of a container of packaging materials into the sterile area,” says Stewart. “Batch sizes are becoming smaller so single-use systems and pre-sterilized packaging materials are becoming more attractive.” He explains that “In these instances, the responsibility for the sterilization process passes from the end user to the supplier and therefore the sterilization method is likely to change: a disposable product supply line is likely to be gamma irradiated or sterilized with ethylene oxide by the supplier, whereas the end user would have processed it through a steam autoclave.”
To better understand the current state of sterilization, we asked the experts to discuss current trends. They generally agreed that manufacturers are looking for cost-effective, efficient systems. Rebuilding existing systems instead of buying completely new systems, a trend which offers significant cost savings, is also becoming popular.
“There is a migration away from traditional primary packaging forms, such as glass, to the use of polymers for reasons of security and cost,” says Stewart. “As aseptic standards, the toxicity of products, and the pressure to reduce costs all continue to increase, there is increased use of isolators requiring internal bio-decontamination.” Stewart continues: “Equipment solution providers such as Telstar are under pressure to reduce the downtime of production equipment by shortening sterilization cycles through the use of innovative technologies such as ionized hydrogen peroxide.”
Anthenat notes that methods that are not particularly environmentally friendly are becoming less popular. “In general, the trend is away from potent gaseous vapors such as EtO, formaldehyde, etc., (in North America and other parts of the world) due to the environmental issues associated with their use,” he says. He adds that new technologies which use high-energy waves are emerging and "gamma, VHP, and other such methods continue to provide options with their own benefits and drawbacks.”
Refurbishing existing sterilization systems is also becoming a prevalent trend. “Given the current economic climate, we have seen a tremendous shift from new equipment acquisitions to field refurbishments and repurposing of sterilization systems,” says Mitchell. “We have seen a large increase in the number of systems we have rebuilt for clients using new piping and controls on older chambers.” Mitchell explains that his company has “rebuilt numerous systems, from all autoclave manufacturers, over the last year — which has helped clients save 40 percent to 50 percent over the cost of a new chamber, without any compromise in quality.”
Possible Future Trends
Although it can be hard to pinpoint the sterilization developments that are around the corner, the experts offered some valuable concepts.
Mitchell sees a number of possible future trends. He notes that “continued pressure on budgets, necessitating creative approaches to meeting production demands,” a “greater shift to alternative sterilization methods due to the single-use temperature-sensitive products delivering the medicines,” and the “adoption of stricter recording standards due to availability of more sophisticated instrumentation and information management systems” are all possible future trends.
Stewart offers another vision: “In the future, primary packaging facilities will be smaller and more flexible and will operate within isolation technology.” He explains that “such environments will need the support of several integrated sterilization technologies for introduction of products and materials and safe removal of waste.” A “single isolator system could be equipped with small, pass-through chambers providing sterilization, surface decontamination, and depyrogenation services with the support of flexible automated handling systems,” he adds.
Anthenat also sees the possibility of new technologies and possibly an entirely new idea of sterilization in the future. “There are several new technologies that are continuing to emerge that revolve around the use of high-energy waves that offer the benefit of sterilization at normal temperatures, such as infrared radiation.” Anthenat notes that as these methods are developed and tested, the entire landscape of sterilization could change in years to come.