Include Extractables and Leachables Testing in Stability Protocols When Needed

Understanding the Tip:

Why extractables and leachables (E&L) matter in stability:

Extractables are compounds that can be released from packaging materials under aggressive conditions, while leachables are those that migrate into the product under actual storage conditions. When left unchecked, these compounds can compromise drug purity, potency, and safety. E&L testing during stability ensures the container-closure system does not negatively impact product quality over time.

When is E&L testing required during stability?

E&L testing becomes essential when the product is a biologic, parenteral, inhalation drug, or uses novel packaging materials like multi-layered plastics or rubber stoppers. It’s also necessary if degradation trends suggest chemical migration, or if prior extractables studies identified high-risk substances. Failure to include E&L when indicated may result in regulatory queries or delayed approval.

Regulatory and Technical Context:

ICH Q3E and global regulatory expectations:

ICH Q3E specifically addresses the need for leachable testing when a risk of interaction exists. US FDA, EMA, Health Canada, and WHO TRS 1010 emphasize container-closure system integrity and its effect on product stability. CTD Module 3.2.P.7 must describe the packaging and any relevant E&L data. Leachables are often tracked as part of long-term and accelerated stability to assess cumulative impact over time.

Audit readiness and submission significance:

During inspections, regulators expect

evidence that leachable risks have been considered. If data is missing or if leachable spikes are observed without explanation, the product may face shelf-life limitations or post-approval testing requirements. Submissions should include E&L summaries in Modules 3.2.P.5.5 and 3.2.P.8.3, especially for high-risk dosage forms.

Best Practices and Implementation:

Conduct extractables studies before initiating stability:

Perform a thorough extractables study using aggressive solvents and elevated conditions to identify potential leachable candidates from packaging materials. Use multiple analytical techniques (e.g., GC-MS, LC-MS, ICP-MS) and maintain a database of compounds with chemical identities, retention times, and toxicological thresholds.

This data forms the basis for targeted leachables monitoring during stability.

Integrate leachables testing into your stability protocol:

Include specific test parameters in the protocol for high-risk time points (e.g., 6, 12, 24 months) or storage conditions (e.g., 40°C/75% RH). Monitor for known leachables using validated methods with sensitivity below the safety thresholds. Define action limits, reporting levels, and OOS criteria in alignment with toxicological risk assessments (e.g., TTC or PDE).

Apply bracketing strategies where packaging material variants are used and ensure that test frequency is justified in the protocol.

Document results clearly and act on findings:

Include E&L results in the final stability reports and trend them alongside physical, chemical, and microbial attributes. Highlight any upward trends, correlate with extractables profile, and initiate risk assessments if thresholds are breached. Use these insights to adjust packaging, revise specifications, or initiate toxicological reviews as needed.

Maintain traceability between E&L results, stability conditions, and packaging lots in both regulatory submissions and internal audits.