How Small Leaks Affect Shelf Life?

Shelf life is defined as the period of time that a product remains stable, unchanged in terms of claimed performance or properties and fit for intended use. Shelf life is based on the assumption that a package remains intact for the duration of storage and use. Even very small leaks can invalidate shelf-life claims by allowing slow, continuous ingress of environmental contaminants (i.e. Oxygen, moisture, bacteria) that degrade product quality over time.

Why small leaks are often overlooked

Small leaks may not cause immediate failure. Packages can pass release testing and still fail months later during stability studies or real-world storage. Stability failure can be the result of barrier property failure or the presence of a leak. Leakage that leads to stability failure can often be detected using deterministic methods. IN cases where effective deterministic methods are not deployed to assure package quality, a greater probability of stability failure exists.

Impact of small leaks on product stability

Small leaks can affect shelf life by:

• Microbial ingress leading to sterility loss
• Moisture ingress that degrades lyophilised or hygroscopic products
• Oxygen ingress causing oxidation of sensitive formulations
• Loss of container headspace control

These effects may occur gradually, making root cause analysis difficult once failure is observed.

A Real World Example

Infant nutrition is typically packaged under modified atmosphere to prevent rancidity. A common shelf-life test is to monitor the Oxygen level in a package 6 days after it has been packaged. Oxygen levels should be below a 3% pass/fail threshold. Controlled defect packages that had a 50-micron leak did not break the 3% pass/fail threshold, yet a 50-micron defect would continue to allow oxygen ingress into the package significantly affecting stated shelf life. The presence of a 50-micron leak could be readily detected at ‘time-zero’ using a deterministic method.

Environmental stress accelerates failure

Temperature fluctuations, pressure changes, and material ageing can enlarge or activate marginal defects over time. A leak that poses minimal risk initially may become critical halfway through the shelf life. This is why shelf-life claims must be supported by integrity data, not assumptions.

Role of CCIT in shelf-life assurance

Deterministic CCIT identifies leaks at sizes relevant to long-term risk. By establishing leak detection thresholds linked to maximum allowable leakage limits (MALL), manufacturers can ensure that packages remain protective under real-world conditions.

CCIT also supports:

• Stability study design
• Validation of packaging changes
• Investigation of late-stage failures

Conclusion

Shelf life is only meaningful if package integrity is maintained throughout it. Small leaks silently erode that integrity over time. Deterministic CCIT provides the measurable evidence needed to protect shelf life claims and patient safety.