Unveiling Annex 1: Navigating Compliance for Users of Mesa Labs Biological Indicators
On 25 August 2023, Annex 1 of The Rules Governing Medicinal Products in the European Union Volume 4 EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use¹ becomes effective. The annex specifically covers Manufacture of Sterile Medicinal Products and replaces a previous version of the document which was in place since March 2009. The purpose of the update is “to reflect changes in regulatory and manufacturing environments and to remove ambiguity and inconsistencies and will take account of advances in technologies.” The new version is approximately three-fold longer than its predecessor, much of which is regarding the equipment used in aseptic preparation and processing.
The annex “provides general guidance that should be used in the design and control of facilities, equipment, systems, and procedures used for the manufacture of all sterile products applying the principles of Quality Risk Management (QRM), to ensure that microbial, particulate and endotoxin/pyrogen contamination is prevented in the final product.”
Mesa Labs, as a supplier of biological indicators (BI) and process challenge devices (PCD®) to manufacturers of sterile product, is subject to various sections within these guidelines. The purpose of this Spore News is to address areas of the Annex that specifically pertain to the above mentioned lethality indicators and the controls Mesa has in place to demonstrate compliance. Section 8.43 addresses BIs and is presented below:
8.43 “The reliability of BIs is important. Suppliers should be qualified and transportation and storage conditions should be controlled in order that BI quality is not compromised. Prior to use of a new batch/lot of BIs, the population and identity of the indicator organism of the batch/lot should be verified. For other critical parameters, e.g. D-value, Z-value, the batch certificate provided by the qualified supplier can normally be used.”
The first actionable item, “Suppliers should be qualified”, generally means the user has established confidence that the manufacturer is providing quality product. This confidence is gained either by performing quality system audit(s) of the manufacturer, including relevant standards such as the ISO 11138 series for the manufacture of BIs or by testing critical BI characteristics on incoming BI lots. Section 8.43 suggests that the “population and identity” of the test organism be verified upon receipt of a new BI lot. The success of these tests will help establish confidence that the product labeling accurately reflects BI attributes.
Population verification by the user also satisfied the user’s responsibility regarding BI transport. BIs contain viable organisms that are transported long distances and as such, the successful verification of population ensures the product arrived in good working order.
Note: Per ISO 11138-7², the user should be aware of the recommendation to follow the manufacturer’s test methods/materials when performing population verification as these can have a significant impact on the results. Information on the methods recommended by Mesa Labs is addressed on the Mesa website³,4.
A great advantage BI microorganisms have over other biological shipments is they are in spore form. While in this dormant state, the organisms are resistant to environmental stresses which is the reason they are ideal for use in challenging sterilization processes. Most BIs are designed to keep the spores dormant by denying them the elements they need to germinate (e.g.,
nutrients, moisture, temperature). Liquid submersible biological indicators (LSBI) are an exception to this as the spores are suspended in a nutrient growth medium at all times. To prevent germination, the temperature must be controlled below the growth range of the test organism. This is generally not a concern with LSBIs containing thermophiles (i.e., Geobacillus stearothermophilus); however, LSBIs containing mesophiles (i.e., Bacillus
subtilis) are a greater challenge as they can germinate at ambient conditions. Tighter packaging and transport controls are utilized when shipping these products.
Mesa Labs has conducted shipping and temperature excursion studies to evaluate the effects variable shipping and transport conditions have on product performance. These studies include the majority of BI formats under a wide range of conditions. Mesa Labs is aware the transport packaging may not maintain the biological indicators within the recommended storage conditions during shipment; however, performance testing of the biological indicators after the excursion conditions were experienced during transport
demonstrates there is no compromise to the biological indicator’s performance.
Mesa Labs, unlike most of our business partners, does not manufacture sterile product. Quite the contrary, biological indicators by design contain high counts of resistant organisms. However, there are areas of the manufacturing process where strict aseptic techniques are used, primarily in spore crop preparation activities. The risk to spore crop purity is greatest at this point as
any contaminants present may have the opportunity to proliferate along with the targeted species (e.g., Bacillus atrophaeus or Geobacillus stearothermophilus). Additionally, post-spore crop production testing is conducted to verify purity and other precautions are taken in the manufacturing process to minimize microbial contamination.
The identity of the test organism is verified at defined steps including on the source microorganism (obtained from a recognized culture collection) used
in crop production as well as on the final spore crop itself. Methods for identification include traditional biochemical/morphological processes as well as 16S rRNA testing5. Information on the methods recommended by Mesa Labs is addressed on the Mesa website6,7,8. Regarding confirmation of the D-value and z-value, section 6.1.5. of ISO 11138-7² states “testing of the resistance characteristics by the user is considered unnecessary provided the user uses the biological indicator as intended by the biological indicator manufacturer.” Section 8.43 of Annex 1 concurs when stating “For other critical parameters, e.g. D-value, Z-value, the batch certificate provided by the qualified supplier can normally be used.” Resistance testing is burdensome, potentially consuming hundreds of BI units and requires specialized test equipment (i.e., a resistometer9), which most companies do not possess.
Mesa agrees that resistance testing is unnecessary especially once confidence is gained in the BI manufacturer through the other mentioned activities.
Although BIs by their very design are not sterile, the manufacturing controls employed during their production are quite similar to those used by other medical device manufacturers, with the noted exception of a sterilization
process. Equipment, utilities, personnel, and the manufacturing environment are controlled per Good Manufacturing Practices (GMPs). Mesa is certified to
ISO 13485 and complies with FDA 21 CFR Part 820.
Additional information in Annex 1 regarding BI usage is in Section 8.42 which states in part “If BIs are used, strict precautions should be taken to avoid transferring microbial contamination to the manufacturing or other testing processes”. The spore component of BIs is contained in the primary packaging which remains intact until the time of culturing (depending on the
BI configuration). There is little risk of the surrogate organisms in the BIs contaminating the production environment10.
The final sentence of section 8.42 states, “BI results in isolation should not be used to override other critical parameters and process design elements.” BI
results, along with the physical data collected during a sterilization process, are complementary to each other. Selection of the appropriate BI for monitoring the sterilization process is necessary and is identified in the sterilization cycle development/validation process. The critical parameters of the sterilization cycle can be monitored in real time, while the results of the BIs are known after an appropriate incubation period.
Annex 1 addresses the requirements for manufacturers of sterile products. Mesa Labs, as a supplier of biological indicators to this industry, complies with the appropriate section of the guideline as described above. All critical performance information is reported on the Certificate of Analysis (CoA) for each BI lot. A review of this information by the user is crucial to ensure that the lot is appropriate for use in their particular situation. This review along with the incoming testing activities ensures the BIs will perform as declared on the CoA.
¹The Rules Governing Medicinal Products in the European Union Volume 4 EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use, Annex 1 Manufacture of Sterile Medicinal Products
²ANSI/AAMI/ISO 11138–7: 2019, Sterilization of health care products Biological indicators—Part 7: Guidance for the selection, use and interpretation of results
³SN075 Spore News Reference Review - End-User or Third-Party Population Verification
4Webinar - Incoming Testing: Population Assessment
5Spore News Vol 1 No 4 The Importance of 16S rRNA Bacterial Spore Identification
6SN077 Spore News Reference Review - End-User or Third-Party Organism Identification and Purity
7Webinar - Incoming Testing on Biological Indicators: Purity & Identification
8Spore News Vol 14 No 1 Sub-culturing a Positive Biological Indicator for Identification
9ANSI/AAMI/ISO 18472: 2022, Sterilization of health care products—Biological and chemical indicators—Test equipment.
10Spore News Vol 4 No 5 Will Biological Indicator contaminate my production environment?