There is no worse feeling than performing a sterility test on a batch of a product only to have the product fail the test and be positive for microbial contamination. It is far from a perfect process, being both time consuming and labour intensive, but it is the best currently on offer.
So how should the manufacturing process move on after a batch of the product fails the sterility test? What procedures should be in place to handle such a failure? And how can you turn advance preparation for a test fail into part of your ongoing processes that will help you avoid such an event in the first place?
The sterility test is a critical touchpoint before product release
The sterility test is a microbiological test required by all pharmaceutical regulators. It looks at a portion of batches to see if they produce microbial growth after 14 days of incubation in appropriate media.
Performing the test is crucial because releasing a contaminated batch of a product can carry extremely serious consequences for both public health and business reputation, as so tragically demonstrated in the case of the NECC.
The required, successful completion of the sterility test is often the last step before a product can be shipped out. Failing the sterility test results in quarantining the affected batch.
An investigation to determine how the sterility test failure occurred will follow. This will mean suspension of production while every stage of your manufacturing and testing process is examined for potential areas of risk.
The better prepared you are for this potential situation, the more quickly you should be back up and running again.
Start by retracing the steps in your aseptic manufacturing process
Every manufacturer of sterile products needs a clear investigation procedure in case of a failed sterility test. The investigation procedure needs to lay out who should do what and what should be examined. The best way to tackle this is with a checklist.
Have a checklist of actions to follow after your sterility test fail
As with aviation or surgery, there are a lot of specific, critical steps in every procedure: too many for one person to remember off the top of their head.
Having checklists ensures that those steps have been completed in a consistent and efficient manner, while also freeing the investigator from planning next steps while analysing results.
Checklists during maintenance, the manufacturing process, sterility testing, and sterility test failure investigation will speed up the investigative process by making each step and their correct order clear. They will also provide information about the equipment and process leading up to the failure, making it easier to spot and resolve problems.
Audit your lab and how it is set up to handle sterility testing
Your checklists to handle a sterility testing failure should begin with the test itself. Problems in sterility testing could lead to a test failure and need to be carefully examined.
Using positive and negative controls, like method validation, the experimental setup itself can be examined as a source of the contamination. The testing equipment and environment, such as reagents, clean rooms, and isolators, need to be certified as sterile, well maintained, and not expired.
The checklist of items to review before performing sterility testing is similar to the checklist to rule out testing issues in the case of a sterility testing failure. This can be used to pre-emptively check for issues such as old reagents and missed maintenance.
Follow your manufacturing and filling process for your failure investigation
Manufacturing and filling processes needs to be examined to find potential sources of the contamination issue.
Materials used in the manufacturing process, the manufacturing environment, the sterilization procedures, the manufacturing and filling processes, the operators controlling the processes, and even the cleaning and disinfection records must be reviewed.
The checklist here should be used to ensure that the manufacturing and filling process examinations are done thoroughly and safely. This can also be used during routine manufacturing and filling to ensure that the proper records, tools, and manuals are easily available and help prevent future failures by ensuring that maintenance is properly performed.
Preparation ahead of handling a sterility test fail reduces negative impact
Preparing your checklists now, ready to perform in the case of a sterility testing failure, gives you a head start if it does become necessary to find and address a contamination source.
Every facet of your facility, manufacturing and testing processes will fall under scrutiny. Many people will be involved, equipment will be out of commission and you will lose revenue. Planning ahead for any potential problems will mean time is not wasted inventing, or re-inventing, procedures over and over, or draw out the investigation unnecessarily.
Preparing in advance for a potential sterility testing failure can also highlight areas of risk in the manufacturing, filling, or testing processes before a sterility testing failure occurs, allowing them to be addressed well before an actual problem can arise. Additionally, these preparations can be based on, or double as, regular maintenance procedures, ensuring consistency in standards across your facility.
A sterility test failure is a dreaded situation for those involved in the manufacturing of sterile products. However, being prepared for that possibility is the best way to effectively and economically handle a test failure and address the root cause.
Creating checklists that lay out clear response procedures will reduce its impact while maintaining testing integrity. Using those checklists regularly as a basis for maintenance will make handling a sterility test failure more efficient, resolving it as quickly and painlessly as possible – or ideally help you avoid it all together.