This informal CPD article ‘Beyond the Barrier: What Inspectors Expect from Isolators and RABS’, was provided by Pharmalliance Consulting, who offer specialist support to pharmaceutical companies to maintain and increase quality compliance levels.
Investing in barrier technology doesn’t automatically guarantee compliance. Whether it’s an isolator or a RABS, regulators are no longer impressed just by the presence of a physical barrier. They want proof that the barrier is being used correctly, and that it’s actually reducing risk.
Design Is Just the Start
Inspectors want to see that the system is designed with purpose. Isolators must be fully closed and airtight, with validated decontamination cycles and routine leak testing. RABS, particularly open ones, are expected to be used in Grade B environments with tight controls on interventions.
It’s not enough to have a smoke study on file. That study needs to be recent, recorded, and include dynamic conditions. Inspectors increasingly want to see smoke studies performed during actual interventions, with operators in place, to confirm unidirectional flow is preserved where it matters most.
Gloves Are a Known Weak Point
One area under intense scrutiny is glove integrity. Regulators expect routine leak testing, often before and after each campaign for isolators, and visual inspections supported by SOPs. Damaged or degraded gloves are seen as a direct breach in containment. Inconsistent glove replacement, unclear testing intervals, or reactive maintenance draw immediate attention.
Interventions: Define and Simulate
One of the clearest trends in both FDA and EU inspections is the demand for a defined list of interventions. Not just “manual intervention,” but exactly what is being done, how often, with what tools, and by whom.
Inspectors now expect that list to be risk-ranked, incorporated into the contamination control strategy, and simulated during media fills. Incomplete simulations or generic assumptions are not acceptable. Media fills should mirror real-world complexity, this includes unusual line stoppages, manual component additions, or routine adjustments.
Maintenance Practices Under the Microscope
Inspectors are increasingly asking to see how isolators and RABS are maintained. That includes the frequency of filter replacements, performance checks on decontamination systems, and how often glove ports are serviced or inspected. Facilities that rely heavily on their barrier system, but treat it as static equipment, are getting flagged. If a fan motor fails or a gasket wears out, it could compromise the entire aseptic state. Preventive maintenance records should clearly show that critical elements are serviced before they fail, not after.
Operator Use and Access Control
In several recent FDA observations, sites were cited not because their isolators were poorly designed, but because operators were bypassing procedures. This included practices like prematurely opening isolator doors, skipping integrity checks, or moving components in and out without following validated workflows. Inspectors now ask how access to isolator doors or RABS panels is restricted and monitored. Facilities that use electronic logs, interlocks, or surveillance footage to confirm compliant usage have fared better in reviews.
Barrier System Failures Should Trigger More Than Repairs
A final area of focus is how facilities respond when barrier systems fail. For example, if a leak is discovered or a smoke study shows disturbed airflow, what happens next? Strong responses go beyond technical fixes. They include deviation investigations, impact assessments for batches, and updates to training and procedures. Inspectors want to see that the failure of a barrier prompts a reassessment of contamination risks, not just a work order and a reset.
Conclusion
A barrier is only as strong as the controls behind it. Regulators want more than engineering, they want evidence of thoughtful operation, meaningful validation, and disciplined execution. If you’re relying on a barrier system to protect your product, be ready to show that you know how to use it, monitor it, and maintain it.
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References
The European Commission, 2022. EU Annex 1, Brussels, Belgium.
U.S. Food and Drug Administration, 2004. Part 210 – Current Good Manufacturing Practice in Manufacturing, Processing, Packaging, or Holding of Drugs, United States of America.
U.S. Food and Drug Administration, 2004. Part 211 – Current Good Manufacturing Practice for Finished Pharmaceuticals, United States of America.
