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Packaging validation should be one of the more straightforward milestones in bringing a medical device to market. The standards are well-established. The test methods are proven. The documentation requirements are clear. And yet, across more than two decades of contract manufacturing and validation work at Life Science Outsourcing, packaging-related gaps remain one of the most misunderstood sources of FDA clearance delays that I see.
The pattern is consistent. A company invests months or years developing a device, builds a strong design history file, prepares a thorough submission — and then discovers that their packaging validation has a gap that generates an Additional Information request or, worse, forces a redesign and resubmission.
It’s common to find at least one significant validation gap in previously executed packaging programs. The issue is rarely a lack of testing capability. More often, it is a failure to align packaging validation strategy with regulatory expectations early enough in development.
The frustrating part is that these delays are almost always preventable. Across thousands of programs in sterile barrier packaging and device assembly, the same five mistakes appear again and again.
1. Treating Packaging as a Late-Stage Requirement
The most consequential mistake happens before any testing begins: packaging gets treated as something to figure out after the device design is finalized. The team often selects off-the-shelf designs that are not necessarily made for their device — then asks someone to validate the choices they have made with the hope that the configuration works.
The problem is that FDA expects packaging to be included in the design controls process. Under design controls, packaging is part of the product design itself. ISO 11607 doesn’t exist in isolation; it connects to the broader design and development framework under 21 CFR 820 (and now the QMSR). When packaging decisions aren’t documented as design inputs — with requirements, risk analysis, and rationale captured in the design history file — reviewers notice. And they ask questions.
The practical consequence is worse than a documentation gap. When packaging is treated as an afterthought, teams discover problems — material incompatibilities for sterilization, seal integrity issues, sterile barrier failures — after they’ve committed to a configuration. At that point, fixing the problem means re-tooling, re-testing and repeating validation work on a program that may already be approaching submission.
The fix is straightforward. Packaging requirements should be defined alongside device requirements early in development. Materials, sealing parameters and sterile barrier configuration should be evaluated as design variables, not fixed decisions. Document the rationale for your packaging choices the same way you document every other design decision. Companies that incorporate packaging strategy during design typically avoid the costly cycle of late discovery and revalidation.
2. Not Defining Worst-Case Conditions
A packaging validation protocol that only tests nominal process parameters is incomplete — and FDA knows it. The purpose of validation is to demonstrate that your packaging process consistently produces compliant results across the full range of operating conditions it will encounter, not simply under ideal settings. That means identifying and testing at worst-case.
For heat-sealed sterile barrier systems, define the upper and lower limits of your sealing parameters — temperature, pressure, and dwell time — and test at those edges, not just at the center of the process window. If your sealer operates between 120°C and 160°C, validating only at 140°C tells FDA nothing about what happens at the boundaries.
The same principle applies to environmental conditions. If your device expects to travel through frozen, tropical or arid conditions, fluctuations in humidity and temperature can influence seal quality and material performance. Those variables need to be accounted for in the validation. And the worst-case challenge needs to be justified, not assumed, based on your actual distribution pathway.
When protocols lack a clear worst-case definition, or when the justification for the challenge conditions is thin, FDA reviewers will push back. The resulting Additional Information request doesn’t just delay your timeline, it often requires additional testing that should have been done the first time.
3. Misapplying Accelerated Aging Information
Shelf-life claims require aging data, and most companies can’t afford to wait for real-time results before submitting. That makes accelerated aging studies under ASTM F1980 a critical path item. But the number of companies that get accelerated aging wrong, or try to submit without it, is remarkable.
The most common errors fall into three categories. First, temperature assumptions. Accelerated aging calculations rely on the Arrhenius equation, which estimates material degradation rates as temperature increases. The calculation requires assumptions about ambient temperature and the Q10 factor, which represents the rate of reaction increase for every 10°C rise.
In medical device packaging validation, a Q10 value of 2 is commonly used unless material-specific data supports a different factor. When protocols use unrealistic ambient assumptions or fail to justify the selected Q10 value, reviewers may question the validity of the aging model.
In addition, using the wrong elevated temperature for your accelerated aging can cause unwanted effects on packaging and the device itself. Materials typical to medical device packaging generally do not withstand accelerated aging temperatures above 60°C without some sort of warping, discoloration or delamination.
Another frequent issue is inadequate sample size planning. Aging studies require enough samples to perform testing at every time point and across all required test methods, including seal strength, bubble leak, dye penetration and sterile barrier visual inspections.
Protocols that underestimate sample requirements often reach the testing phase only to discover that additional samples are needed. Sampling plans can follow the general guidelines for confidence and reliability. Statistical justification in your sample size avoids unnecessary scrutiny from FDA. Using these guidelines helps to predict the total number of sterile barrier systems with the device or dunnage needed to support a packaging validation.
Third, the absence of a concurrent real-time aging arm. Accelerated aging supports initial shelf-life claims, but FDA expects concurrent real-time aging studies to be initiated as confirmation. Submissions that rely solely on accelerated data without a documented real-time plan will trigger questions.
4. Treating Distribution Simulation as a Checkbox
Distribution simulation testing often uses ASTM D4169 to expose weaknesses in shipping configurations and sterile barrier defects. The simulation is where packaging validation meets the physical reality of how devices move through the supply chain. And it’s where companies most often take shortcuts.
The typical shortcut is using a generic distribution cycle that doesn’t reflect the actual conditions the package will face. ASTM D4169 provides a framework with multiple distribution cycles for different scenarios, but it’s the manufacturer’s responsibility to select, and justify, the appropriate one.
Another common gap: testing distribution simulation in isolation from the rest of the validation sequence. The packaging system needs to maintain sterile barrier integrity after the combined stresses of distribution and aging, not just each one independently. The sequence of testing matters, and protocols that don’t account for cumulative stress exposure are incomplete.
Altitude simulation is one test that is often missed. If your primary sterile barrier is made of non-porous materials, low pressure could affect that barrier by weakening it or causing it to rupture. It is also important to keep in mind if your device has closed cavities that contain air. The expansion during low pressure can prevent the device from functioning correctly. Remember, testing the worst-case scenario will help prevent doubts during submission and possibly avoid costly recalls.
When FDA questions the adequacy of your distribution simulation, the fix isn’t just running more tests. It often means going back to justify your distribution cycle selection, which means going back to map your actual supply chain — work that should have informed the protocol design from the start.
5. Documentation Doesn’t Tell the Story
The most common documentation failures include missing or inadequate rationale for acceptance criteria; insufficient traceability between the validation protocol, test reports and the design history file; missing justification for sample sizes; and incomplete documentation of deviations and how they were dispositioned. Each of these, on their own, might only generate a clarifying question. Together, they create an impression that the validation program wasn’t rigorous, even when the actual test data is solid.
FDA reviewers are reading dozens of submissions. They’re looking for confidence signals — evidence that the company approached validation systematically and that every decision is traceable. When the documentation forces the reviewer to connect dots that should have been connected for them, the result is an Additional Information request that costs weeks or months.
The discipline here is simple but frequently skipped: write protocols as if the reader has no context. Justify every acceptance criterion. Document every deviation and its disposition. Make the traceability from design input to validation output explicit. If a reviewer can follow your logic without picking up the phone, you’ve done it right.
Getting Ahead of the Problem
None of these mistakes is exotic. They don’t require cutting-edge technology to fix or enormous budgets to prevent. They require a disciplined approach to packaging validation that treats it as what it is: a critical-path regulatory deliverable, not a box to check at the end of development.
Matthew Emrick is MPT Supervisor of Medical Package Testing at Life Science Outsourcing.
