Release testing

Release testing is a final quality check that evaluates a finished batch against a predefined specification. This specification consists of a fixed list of quality attributes, test methods, and pass-fail limits. The primary purpose of release testing is to confirm that a batch meets these standards by measuring identity, purity, and safety.

Core attributes verified during release testing

• Identity confirms the substance is what it claims to be, often established through mass spectrometry.
• Purity quantifies the active component and detects impurities, typically using HPLC.
• Safety verifies the product is free from harmful contaminants.

Common report misinterpretations and related testing types

A legitimate lab report or Certificate of Analysis (CoA) must show specific data for individual impurities, not only an overall purity percentage. A report stating "99% pure" without identifying the remaining 1% does not meet standard requirements. Likewise, a single HPLC purity percentage cannot definitively establish identity; confirming the actual substance requires a separate method such as mass spectrometry.

Release testing is the final check performed on a finished batch and is distinct from other testing types. In-process testing takes place during manufacturing, while stability testing is an ongoing check of how a product degrades over its shelf life. Real Time Release Testing (RTRT) is a modern alternative that relies on manufacturing process data instead of traditional finished-product laboratory testing. Unregulated vendors may use the term "release testing" without following strict regulatory validation requirements.

Sources

1. Real Time Release Testing guideline - EMA - European Union
2. Guidance for Industry
3. Q6A Specifications: Test Procedures and Acceptance Criteria ... - FDA
4. ICH Q6B Specifications: test procedures and acceptance criteria for biotechnological/biological products - Scientific guideline | European Medicines Agency (EMA)
5. Q6A Specifications: Test Procedures and Acceptance Criteria for New Drug Substances and New Drug Products: Chemical Substances | FDA
6. [PDF] Guidance for Industry- Synthetic Peptides - FDA
7. Using mass spectrometry for robust identity release testing in ... - PMC
8. Liquid Chromatography-High Resolution Mass Spectrometry for Peptide Drug Quality Control - PMC
9. FDA Sets Peptide Impurity Thresholds as Low as 0.10%, Oath Research Analysis Finds
10. ICH Q6A specifications: test procedures and acceptance criteria for new drug substances and new drug products: chemical substances - Scientific guideline | European Medicines Agency (EMA)
11. Q6B Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products | FDA
12. Real time release testing - Scientific guideline | European Medicines Agency (EMA)
13. ICH Q8, Q9 and Q10 Questions and answers (R5)
14. Guideline on Manufacture of the Finished Dosage Form
15. Q 1 A (R2) Stability Testing of new Drug Substances and Products
17. Expiration Dating and Stability Testing for Human Drug Products | FDA
18. Amphiphilic Dicyclopentenyl/Carboxybetaine-Containing Copolymers for Marine Fouling-Release Applications