Current practices for cleaning and sterilizing biomanufacturing equipment does not differ much between a multi-product versus single-product setting.
When it comes to cleaning validation in the biopharmaceutical industry, different biopharmaceutical manufactures face similar challenges. Some common challenges include the ability to have reproducibility when manually cleaning small parts and when using non-clean-in-place (CIP) systems as well as having an effective design in which CIP systems are fully automated.
Other challenges include a physical build-up of protein on equipment walls that have been cleaned by CIP. This build-up is a process that happens over time when there is no periodic scrub-down of the equipment, allowing for a layer of residue to accumulate in the inner surface of the vessel. In addition, failure of CIP systems over time due to blocked steam traps, poor maintenance, or irregular/erroneous replacement of a steam trap will pose problems for cleaning validation operations (1).
Because cleaning validation is an important aspect in current good manufacturing practice (cGMP) manufacturing for monoclonal antibodies (mAbs) as well as other biologics, it is important to consider how current practices ensure that cleaning and sterilizing biomanufacturing equipment is conducted properly, and whether differences exist between cleaning and sterilizing equipment used in multimAb product versus single-mAb product manufacture in the same facility.
To start with, no real differences exist between single-mAb and multimAb product manufacture in regard to cleaning and sanitation/sterilization, industry experts say. Cleaning protocols would be similar in both circumstances. However, it is important to note that there would be no concern with active carry-over in singleproduct facility as there would be in a multi-product facility.
In the case of AstraZeneca’s Frederick Manufacturing Center in Frederick, MD, for example, the acceptance criteria for sterilization in place (SIP) is based on the European standard EN285 and is non-product specific, according to an AstraZeneca company official.
“The acceptance criteria for cleaning are non-product specific because sampling assays and each [n]ew [p]roduct [i]ntroduction (NPI) are challenged on a small-scale (i.e., recovery/cleanability), and protein denaturation (i.e., degradation of proteins using in-house chemicals) needs to be demonstrated to verify that the facility is fit. Each program (cleaning/SIP) has on-going monitoring/maintenance program executed annually to verify systems remain in a validated state,”the AstraZeneca official states.
“Cleaning protocols between a single-mAb and a multi-mAb manufacturing facility would assess the degraded product as an organic impurity in the drug substance of the next batch,” notes Paul Lopolito, senior manager, STERIS Technical Services. “In a multi-mAb product facility, the main difference is having to assess the cross-contamination risk of mAb product process contaminants with the quality attributes of a subsequent, different mAb drug product,” adds Beth Kroeger, manager, STERIS Technical Services.
“A risk assessment should include an assessment of active degradation rinsability, toxicity, host cell proteins, media, cleaning agent residues, cleaning process capability, and bioburden and bacterial endotoxin,” notes Kroeger.
In a biomanufacturing facility where multiple mAb therapeutics are produced, it is important to note what types of cleaning validation are necessary, and how often validation must be performed. The AstraZeneca official notes that cleaning validation maintenance is performed annually at the company’s Frederick facility using a matrix approach. “For each NPI, small-scale cleanability/recovery, protein denaturation, and large-scale cleaning verification (matrix approach) are required,” the official states. In addition, establishing if the product is more challenging to clean compared with previous products will determine the requirements for cleaning validation/verification.
Lopolito points out that a risk assessment should be performed for incoming mAb drug-product toxicity, solubility, degradation product rinsability, media, and buffer constituents compared to the existing validated cleaning procedures for the entire process for the current products. “If this new mAb is not considered worst case, then at least one production run under normal process conditions for cleaning validation or verification should be executed. Provided no significant changes are made to the process, revalidation is generally not required. Continued process verification should be in place to trend quality attributes to establish cleaning process capability and performance control,” he explains.
Systems must be in place that help maintain a sterile environment for manufacturing. In terms of cleaning and SIP validation, all equipment, systems, and production parts used for manufacture should be cleaned with a validated cycle prior to use, the AstraZeneca official says. “Cleaning cycles demonstrate that equipment surfaces are clean and free of residues and ensure any leftover product is cleared,” the official states.
Kroeger notes, however, that no additional systems are required in a multimAb facility compared to a single-mAb facility “unless the facility is manufacturing products such as antibody-drug-conjugates (ADCs), due to the potential increased toxicity from the small-molecule portion of the ADC, or products other than mAbs/large molecule.”
Procedural segregation should exist with separate area clearance between products and batches in a multi-mAb facility, Lopolito adds. “Obviously, packed columns and ultrafiltration membranes would be product dedicated, but equipment need not be dedicated once the resin or membranes are removed. Equipment change-over between products is recommended where elastomeric parts are discarded but is not necessary if cleaning validation testing verifies residue removal from the various materials of construction, or they are not considered to have a significant surface area to exceed the maximum allowed carry over limits,” he explains.
In addition, other procedures, components, and systems that are important to have in place for cleaning validation include automation control, gowning, aseptic practices, changeover requirements, high-efficiency particulate air (HEPA) filtered air, closed systems used for manufacture, positive pressure, isolation valves, external equipment cleaning, room classifications/cleaning, and on-going quality control monitoring, the AstraZeneca official emphasizes.
Meanwhile, the selection of cleaning agents requires certain criteria. Lopolito points out that cleaning agents should be selected based on performance, rinsability, analytical methods availability, low toxicity, lot traceability, and compatibility with materials of construction.
Safety is the most important consideration because of toxicity risks, adds the AstraZeneca official. “Do not select cleaning agents that have significant cytotoxicity, allergenicity, or reproductive hazards,” the official asserts.
In a multi-mAb manufacturing scenario, residue type is also a key consideration when selecting a cleaning agent because it is necessary to ensure that the cleaning agent degrades the residue of each product, product-by-product, the AstraZeneca official says. “Typically, alkaline cleaning agents are used as they are bactericides and emulsifiers [microbial control and dissolving proteins]. Acidic cleaning agents may be used to remove salt deposits. Cleaning chemicals with surfactants and builders, that are compatible and safe, are preferred,” the official says.
Innovations in cleaning/sterilization materials are also important to the process. According to Kroeger, there is at least one cleaning agent that is registered as a biocidal agent with disinfectant, biocidal, and biofilm remediation claims. “Detergent performance enhancements including maintenance derouging, antimicrobial effectiveness, and biodegradability are a few of those being developed to support manufacturers’ process optimization and sustainability goals,” she states.
In addition, a risk-based approach to acknowledge potential failure modes and provide justification on current controls (detection) is in place. It is important to implement this risk-based approach while maintaining the validated state and regulatory requirements, the AstraZeneca official says.
Biostatistical analysis may also be used to establish control limits (within predetermined acceptance criteria) used for continuous monitoring/trending.