How to verify a batch number and COA

What a batch is and what its number identifies

ICH Q7 defines a batch as a specific quantity of material produced through a process or series of processes and expected to be homogeneous within specified limits. Its number is a unique combination of numbers, letters or symbols from which production and distribution history can be determined. The identifier connects records; it is not itself a purity measurement or evidence of a particular analytical outcome (ICH Q7, section 20).

For a practical check, we recommend transcribing the label batch exactly and comparing it with the complete certificate alongside the material name. If a different repackaging code appears, request its documented correspondence with the original batch. We do not recommend inferring dates or manufacturers from a character sequence without a verifiable explanation from the issuer and records linking the identifiers (ICH Q7, sections 9.42, 11.41 and 17.20).

Information a COA should allow you to review

Within its scope, Q7 calls for the material name, grade where appropriate, batch and release date; each performed test should carry acceptance limits and numerical results when the results are numerical. It also addresses a date, authorized quality signature and the original manufacturer’s name, address and telephone number. For RUO review, we recommend checking these fields before interpreting an isolated percentage without its surrounding test and material information (ICH Q7, sections 11.40–11.43).

Alongside the commercial name, we recommend checking which chemical identity is documented and which test supports it. McCarthy describes complementary methods, including NMR and mass spectrometry, for peptide standard characterization. The paper identifies limitations for chiral or isobaric amino acids. A compatible mass should therefore not automatically be interpreted as proof of every structural feature of a sequence or as a substitute for additional characterization where needed (McCarthy et al., 2023; PMID: 36949371).

Method, units and reporting basis

We recommend requesting a procedure identifier or reference and checking what it measures. “HPLC” names a technique but does not alone explain whether a percentage represents chromatographic area or content by mass. McCarthy distinguishes area-based impurities from contributions measured as mass/mass. Comparisons need to preserve that distinction, including the standard used and whether the reporting basis is as-is or water-corrected (McCarthy et al., 2023; PMID: 36949371).

For each row, read result, unit and criterion together: area percentage, mass fraction and amount per vial answer different questions. A limit is not the measured value; “complies” also does not provide a numerical value when one exists. If units or the content definition are missing, we recommend requesting clarification and recording that uncertainty rather than converting one percentage into another or assuming a denominator (ICH Q7, section 11.42; McCarthy et al., 2023; PMID: 36949371).

Dates, laboratory and issuance

Q7 distinguishes release, expiry and retest dates, linking the latter two to stability data. Where an expiry date exists, it calls for it on both label and COA; a retest date belongs on the label, COA or both. We also recommend distinguishing testing from document issuance. Recent issuance does not demonstrate recent testing. If the chronology is unclear, request the corresponding record before treating the result as current (ICH Q7, sections 6.60, 11.41 and 11.61).

We recommend identifying who manufactures, who tests and who issues the document. Q7 addresses certificates reissued by repackers, agents or brokers, calling for laboratory identification, reference to the manufacturer and original certificate, and an attached copy. To check provenance, we suggest confirming the report number through an independently checked issuer contact and retaining its documented reply as part of the review (ICH Q7, sections 11.43 and 11.44).

Traceability and signs of incomplete information

Q7 calls for agents and distributors to maintain traceability through records including manufacturer, purchase, original batches, transport and authentic certificates. For research, we recommend retaining the label, received document and code correspondence together. When reviewing a corrected file, keep the previous version and the explanation for the change, following the principle of document revision control rather than silently replacing the evidence used in an earlier review (ICH Q7, sections 17.20 and 6.11).

Signs requiring further review include absent or conflicting batches, incomplete identification, results without methods or units, limits confused with measurements and unconfirmed provenance. These are documentary gaps; alone they do not prove forgery. We recommend listing each discrepancy and requesting the specific missing information instead of accepting or rejecting the document based on its visual design, logo or the prominence of a purity percentage (ICH Q7, sections 11.4 and 20; McCarthy et al., 2023; PMID: 36949371).

What verification establishes

We suggest closing the review by stating which batch matches, which tests are documented and which questions remain open. A certificate summarizes results; stability requires its own assessment and peptide characterization uses distinct determinations. We therefore do not extrapolate a COA to other batches, untested properties or subsequent storage conditions. The conclusion should remain limited to the material and evidence that can be connected through the available records (ICH Q7, sections 11.40 and 11.50; McCarthy et al., 2023; PMID: 36949371).

Verified references

• ICH. Q7: Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients, Step 4 version, 10 November 2000. Sections 1.1, 6.11, 6.60, 9.42, 11.4, 11.50, 11.61, 17.20 and 20. Open source: https://database.ich.org/sites/default/files/Q7%20Guideline.pdf.
• McCarthy D et al. Reference Standards to Support Quality of Synthetic Peptide Therapeutics. Pharmaceutical Research, 2023. PMID: 36949371. DOI: 10.1007/s11095-023-03493-1.