An interview with Dr Tim Sandle by Cristina Masciola, AM Instruments' Marketing & Communication Manager
Let's talk about a challenging topic for the pharmaceutical industry, the transfer of materials in a contamination controlled area with Dr.Tim Sandle.
Dr. Tim Sandle is a pharmaceutical microbiologist, science writer and journalist. He is a chartered biologist and holds a first-class honours degree in Applied Biology; a Master’s degree in education; and has a Doctorate from Keele University.
The changes required by Annex 1 are important and significant, new Annex 1 elaborates on airlocks and states that they must be designed and used to ensure physical separation and to minimise microbial and particle contamination of different areas. The last step of the airlock must be the same grade as the area to which it gives access.
4.10 The transfer of equipment and materials into and out of the cleanrooms and critical zones is one of the greatest potential sources of contamination. Any activities with the potential to compromise the cleanliness of cleanrooms or the critical zone should be assessed and if they cannot be eliminated, appropriate controls should be implemented. Annex 1
The transfer of materials as well as the associated contamination risks are given great attention in the new Annex 1. The CCS (Contamination Control Strategy) leaves nothing to chance.
What is new compared to past revisions of the document?
In the new Annex, microbiological contamination from materials entering the cleanroom is provided with a far greater emphasis. This has been identified as one of the major routes of contamination for items coming into the facility. The optimal means of transfer is via a double-ended autoclave and using moist heat. Where this is not possible, of where single-use sterile items are required, then a disinfection process is required. This can be automated (as with a decontamination chamber using a vapour like hydrogen peroxide or chlorine dioxide) or a manual process using a transfer hatch equipped with a localised HEPA filter air supply.
The Annex places emphasis upon both cleaning and disinfection. Most disinfectants are very poor at penetrating ‘soil’ and therefore items need to be cleaned prior to the application of a disinfectant.
The Annex also indicates that the disinfectant should be ideally sporicidal and that a sporicide is required for the transfer of materials from Grade C to Grade B. It is also important that items being transferred in are multi-wrapped and that a layer of wrapping can be removed at each stage of the transfer process as the item moves from the external area and through the cleanroom cascade.
What are the most critical steps in the materials transfer process?
Bacterial spores in the Grade A environment present a significant risk of contamination in aseptically prepared products and potential patient harm. Ensuring that any spores (plus vegetative organisms0 are not transferred in from Grade C to Grade B is critical. This is to ultimately protect Grade A environments.
In assessing this, an understanding of how goods arrive at a warehouse and end up in the aseptic processing area.
To carry out this task correctly, a quality risk assessment is required. The risk assessment will need to address:
With the disinfection step, because there is a high risk of contamination therefore the disinfection process must be carefully controlled. Maintaining a wet contact time is critical for effective disinfection. If the validated time is not being achieved, contamination may persist on the surface of the items.
4.11 The transfer of materials, equipment, and components into an aseptic processing area should be carried out via a unidirectional process. Where possible, items should be sterilized and passed into the area through double-ended sterilizers (e.g., through a double-door autoclave or depyrogenation oven/tunnel) sealed into the wall. Where sterilization on transfer of the items is not possible, a procedure which achieves the same objective of not introducing contaminant should be validated and implemented, (e.g., using an effective transfer disinfection, rapid transfer systems for isolators or, for gaseous or liquid materials, a bacteria-retentive filter). Annex 1
The pass-box should have an integrated bio-decontamination system. What are the specific requirements of this integration?
The optimal approach is to automate the decontamination process. This can be put in place using a biodecontamination chamber, for multi-wrapped items. These items must have been sterilised using a proven technology (all items entering Grade A must be sterile). Typically, items are sterilised by radiation (such as gamma, X-rays or electron beam) or sometimes by a penetrative gas (such as ethylene oxide).
The most common technology for this is hydrogen peroxide vapour, although there are alternatives. The advantage is that, through development, the process can be qualified and demonstrated to be consistent. In addition, the level of microbial inactivation is far greater than can be achieved with a manual process. To demonstrate this, biological indicators can be used. It is important that the biological indicators selected have proven resistance to the decontamination agent (such as Geobacillus stearothermophilus for hydrogen peroxide vapour) and are of a suitable population to demonstrate a six-log reduction.
With cycle development, controlling key parameters like temperature, humidity, concentration of the biocide, and the contact time are each essential. Attention should be paid to load configuration and for this all items should be hung so that the decontamination agent can circulate around each item.
Items should also be multi-wrapped, enabling a layer of wrapping to be removed for the eventual transfer into Grade A. This is required because the vapours used for decontamination are only effective on the outer surfaces of the items placed within the chambers, they have no penetrative ability.
And, if they do not have a bio-decontamination system, what are the main activities that can reduce the risk of contamination?
The most important steps for the manual process are to have a well-built transfer hatch (fashioned from good quality stainless steel) the hatch must be equipped with a local HEPA supply capable of delivering Grade A air.
Prior to use, all surfaces of the hatch must be wiped with a sporicide, and then each item going in must also be treated with sporicide. Items should then be placed inside for the duration of the contact time under the localised HEPA airflow. The wiping of items with sporicide is essential, simply spraying is not effective.
Upon removal, the outer layer of each item must be removed.
The science-based philosophy behind the new Annex 1 also affects material transfer activities, for which it is explicitly required:
4.13 Where materials, equipment, components and ancillary items are sterilised in sealed packaging and then transferred into the Grade A zone, this should be done using appropriate, validated methods (for example, airlocks or pass-through hatches) with accompanying disinfection of the exterior of the sealed packaging. The use of rapid transfer port technology should also be considered. These methods should be demonstrated to effectively control the potential risk of contamination of the Grade A zone and Grade B area and, likewise, the disinfection procedure should be demonstrated to be effective in reducing any contamination on the packaging to acceptable levels for entry of the item into the Grade B and Grade A areas. Annex 1.
How might this be achieved?
In summary to what we have covered, there is a hierarchy of transfer methods:
The important message is that all items that are intended for Grade A need to take this route, including culture media to be used for environmental monitoring. Drawing up a list of approved items is essential to avoid anything for being missed. This includes everything from tools to cables. For each item the route to be taken must be understood.
With the Annex 1 updated, ‘static’ pass through chambers with no air supply are no longer permitted. Organisations have until August 2023 to phase these out. Using risk assessment to mitigate this would not be acceptable. Other, old-fashioned means of getting items in, such as personnel transferring items (e.g., via changing rooms) must be prohibited.
To address the challenges introduced by Annex 1, pharmaceutical industries must rely on suppliers who have a deep understanding of GMP and the implications introduced by the new regulations. Since 1990, AM Instruments has been at the forefront of contamination control in the Life Sciences market, with a strong focus on quality requirements.
As a productive industrial reality, the company implements the “GMP Consistent program”, ensuring full synergy of operational modes, objectives, and results with the pharmaceutical market.
AM Instruments offers products, cutting-edge technologies, and services for cleanrooms. AMTech® by AM Instruments manufactures standard and custom-made products through a careful analysis of the customer’s requests and special needs. Our team offer solutions even for complex dimensions, functions and layouts thanks to the support of the highly modern design and production processes. From design to project to realisation, AM Instruments approach is professional, competent and proactive. With its own multifunctional laboratory featuring dedicated working areas for the maintenance, repair and calibration of instruments, AM Instruments offers assistance and services which are among the most professional on the market.
Our internal research and development team has applied the most innovative technologies to develop a new dynamic pass-through hatch, the MyBox®.
MyBox® it’s an effective and reliable decontamination solution for thermolabile materials and electronic components. Our decontamination chambers utilise integrated low-concentration hydrogen peroxide systems (<8%) with HPE technology, based on a hydrogen peroxide solution with a concentration lower than 8% which, passing through a high voltage electromagnetic field, undergoes an ionisation process allowing a high and effective diffusion with validated bio-decontamination cycles and a reduction of the surface microbial load of log 6, including viruses, bacteria, moulds and microbial spores. The system is equipped with a control panel that can be connected to a supervision system for complete automation of the cycle. In the environment, the ionised mist behaves with the dispersion characteristics of a gas:
During the validation phase, chemical and microbiological mapping with bioindicators (Geobacillus Stearothermophilus) is used to ensure the correct distribution and effectiveness of the hydrogen peroxide, guaranteeing the desired level of bio-decontamination.
MyBox® is also easy to install for the passage of material from classified C/D areas into sterile Grade B areas, ensuring the sterilisation of external surfaces. And if you have products/components that aren't autoclavable, MyBox® is an essential device to ensure their complete sterilisation.
Don't take any chances with the safety of your materials and components. Choose MyBox® for the highest level of decontamination and sterilisation.