Pharmaceutical manufacturers are very aware of the European Medicines Agency revisions to “Annex 1 Manufacturing of Sterile Medicinal Products” of the EU Guidelines to Good Manufacturing Process that required compliance provisions to be fulfilled by August 2023.
The EU Annex 1 Good Manufacturing Process (GMP) updated requirements affect the manufacturing of sterile medicinal products from European Member States and products imported from outside Europe.
The revision of Annex 1 provides an update to the guidelines affecting aseptic manufacturing and focuses on the need to provide improved contamination control strategies as well as increased use of automated biodecontamination processes.
The revision of Annex 1 provides an update to the guidelines affecting aseptic manufacturing and focuses on the need to provide improved contamination control strategies
Section 4.22 of Annex 1 specifies that “the bio-decontamination process of the interior should be automated, validated and controlled within defined cycle parameters and should include a sporicidal agent in a suitable form (e.g. gaseous or vaporised form)”.
The section goes on to recommend that irregular and challenging surfaces such as gloves “should be appropriately extended with fingers separated to ensure contact with the agent” and that “methods used (cleaning and sporicidal bio-decontamination) should render the interior surfaces and critical zone of the isolator free from viable micro-organisms”.
Further information with Section 4.36 recommends process changes where fumigation or vapour disinfection (e.g. Vapour-phase Hydrogen Peroxide) of cleanrooms and associated surfaces are used and highlights that “the effectiveness of any fumigation agent and dispersion system should be understood and validated”.
The many factors affecting hydrogen peroxide (H2O2) cycle efficacy – and routine process monitoring
The purpose of the H2O2 cycle is to decontaminate the internal surfaces of the enclosure (such as isolator, room or pass through chamber), as well as any exposed, external surfaces of any items inside it (such as filling and/or process equipment) to create an environment that is fit for onward production use.
Manufacturers of sterile medicinal products will be acutely aware of the numerous challenges to bio-decontamination validation that traditional technologies present - from temperature and humidity and airflow variation affecting hydrogen peroxide concentrations to load item configuration challenges borne from differing, ‘materials of construction’ and risk of occlusion.
The entire internal surface of the isolator cannot be challenged, therefore, specific locations that represent the environment have to be selected
The process and stages of cycle development and validation to achieve consistent levels of ‘Log 6 reduction’ of biological kill can often be challenging to show reproducibility and completion can be affected by time constraints within the project plan. The process of validation has also previously relied upon initial validation and periodic revalidation to assess efficacy.
The entire internal surface of the isolator cannot be challenged, therefore, specific locations that represent the environment have to be selected. Historically, this process has always been problematic due to having to rely on assessment and justification of where potential risk areas may be represented. The task of deciding upon challenge locations, specifically the risk of glove locations, is something that many aseptic pharmaceutical manufacturers find confusing. This is also a “hot topic” when regulatory bodies visit an organisation.
These factors when combined, demonstrate why the task of validating and understanding the bio-decontamination process is particularly challenging.
How does enzyme indicator technology help meet Annex 1 requirements?
Unlike conventional tools, enzyme indicators offer rapid, quantitative feedback in around 60 seconds, per indicator. Due to the speed and quantitative data collection, the technology provides a stronger level of confidence in biodecontamination process and, consequently, a greater data-driven and consistent approach to ensure compliance with Annex 1.
How does enzyme indicator technology work?
The enzyme indicators contain thermostable adenylate kinase (tAK) - an enzyme that is inactivated during the bio-decontamination process. In turn, this is measured and translated into real-time quantifiable results.
Once removed from the enclosure after the bio-decontamination process and inserted into the PR2A reader, the enzyme indicator generates a bioluminescent reaction in the form of a relative light unit (RLU) numerical value.
The first reagent, Luciferin, and its enzyme partner Luciferase are introduced to the process via injection into the test tube containing the indicator, which acts as a marker of the enzyme and produces light.
A second reagent, ADP, is introduced to measure how much of the active enzyme is left as the residual tAK converts the ADP into ATP, amplifying the levels of light produced. Upon the introduction of the ADP, the PR2A readers built-in photometer captures the light reaction and generates a relative light unit value. The higher this value, the more enzyme remains on the strip and, consequently, the less effective the bio-decontamination process has been.
Conversely, a lower relative light value means that less enzyme remains on the indicator, showing the bio-decontamination process has been more effective.
Enzyme indicators provide clear insights
The technology determines the efficiency of biodecontamination by highlighting the differences in the location of any challenge areas used, creating a model of efficacy for the process and enclosure space that’s monitored. This is of particular interest for materials found within the enclosure space that are permeable to hydrogen peroxide, such as gloves and allows for the worst-case challenge locations within the enclosure and load configuration to be identified with ease.
The quantifiable efficacy mapping data means users can visualise and strengthen their challenge location risk assessment with holistic data.
In turn, this data also gives greater insight into the factors affecting the bio-decontamination process information such as the impact of temperature, humidity and hydrogen peroxide concentrations. This means a greater understanding of the boundaries of the process to support the validation within controlled parameters across repeat cycles.
The technology determines the efficiency of biodecontamination by highlighting the differences in the location of any challenge areas used
The non-viable low-risk nature of enzyme indicator technology means that manufacturers can assess the bio-decontamination process on a routine basis before production begins. Consequently, no materials are committed and if biodecontamination process were to fail, there’s no requirement to risk rejection of any material produced. This allows for a change of validation methodology to incorporate continued process verification (CPV) which in turn can reduce the need for periodic requalification and lengthy downtime on the process under test.
Enzyme indicators provide a faster, safer and smarter bio-decontamination validation to be conducted enabling optimised cycle design, reducing the risk of routine failures and providing safer bio-decontamination.
UK-based manufacturer Protak Scientific supply ‘Enzyme Indicators’ - the advanced rapid validation tool for measuring H2O2 gaseous biodecontamination performance to many of the top ten pharmaceutical names including Pfizer, Roche, Sanofi, AstraZeneca, GSK, Novo Nordisk and manufacturers of equipment used during the production of sterile medicinal product and medical devices.
