Don’t Adjust Sampling Volumes Without Documented GMP Justification

Do Not Change Sampling Volumes Without GMP-Approved Justification

Remember: Sampling volumes must follow validated procedures—any deviation must be documented, justified, and approved under GMP compliance rules.

Why This Matters in GMP

Sampling plays a critical role in determining the quality of raw materials, in-process products, and finished goods. Defined volumes are determined during method validation and are essential to ensure consistency, accuracy, and comparability of test results. Adjusting these volumes without proper justification may lead to skewed results, batch release delays, or incorrect pass/fail conclusions. GMP requires that all sampling be traceable and repeatable. Deviations from approved sampling volumes without documentation can compromise data integrity and invalidate analytical outcomes.

Also Read: How to Integrate ANVISA and COFEPRIS GMP Guidelines into Your Pharmaceutical QMS

Regulatory and Compliance Implications

FDA 21 CFR Part 211.160 and 211.165 outline requirements for scientifically sound sampling and testing. EU GMP Chapter 6 mandates that sampling be performed in accordance with documented procedures. WHO GMP and Schedule M require defined and justified sampling strategies for every material type. Regulatory inspectors examine sampling SOPs, deviation logs, and analyst worksheets to verify compliance. Any unauthorized changes to sampling volumes are flagged as data integrity violations and may result in retesting or rejection of analytical results.

Implementation Best Practices

Ensure all sampling

SOPs define precise volume requirements with justifications based on validation data.

Train QC analysts on following sampling instructions and the need to log deviations formally.

Establish a deviation control system where sampling changes must be approved by QA and scientifically justified.

Use electronic logbooks or batch management systems to capture and review any sampling variations in real time.

Include volume verification in internal audits of laboratory sampling practices.

Regulatory References

FDA 21 CFR Part 211.160 & 211.165 – Sampling and Testing Requirements
EU GMP Chapter 6 – Quality Control and Sampling Accuracy
WHO GMP – Sampling Guidelines and Method Verification
Schedule M – Sampling Documentation and Deviation Justification