Glossary
The words on a certificate, defined
Each term gets a plain definition, why it matters on a certificate of analysis, and one worked example. Definitions link to the articles that use them.
Certificate of analysis (CoA)
A document issued for a specific batch of material that lists the tests performed, the acceptance limits and the results obtained, authorised by the issuer's quality unit. It is the evidence of testing that travels with the batch.
Pharmacopoeia
An official collection of quality standards for medicines and their ingredients, published by an authority: monographs with tests, methods and acceptance criteria, plus general chapters. Examples include the USP-NF, the European Pharmacopoeia and the British Pharmacopoeia.
Monograph
The section of a pharmacopoeia that sets the quality standard for one material or preparation: its definition, the tests to be applied, the analytical methods referenced and the acceptance criteria the material must meet.
Specification
The agreed list of tests, references to analytical methods and acceptance criteria that a material or product must meet to be considered acceptable for its intended use. A batch conforms when its results meet the specification's criteria.
Assay
The quantitative test that measures how much of the stated substance the material actually contains, usually expressed as a percentage against the declared or theoretical content, by a defined analytical method.
Out of specification (OOS)
A test result that falls outside the acceptance criteria of the specification it was tested against. An OOS result triggers a documented laboratory investigation before any decision about the batch is made.
Retest date
The date when a material should be re-examined to confirm it is still suitable for use. Unlike an expiry date, a passed retest date does not condemn the batch; it means use should wait for a fresh, representative retest.
Expiry date
The date on the container or label after which a material should not be used, marking the end of the period in which it is expected to remain within its shelf-life specification under the defined storage conditions.
Batch number (lot number)
The unique identifier a manufacturer assigns to one batch or lot of material, tying together its production record, its testing, its labels and its certificate. Traceability starts and ends with this number.
Method reference
The identification, next to each test on a certificate, of the analytical method used: a pharmacopoeial general chapter, a monograph procedure, or the issuer's own numbered in-house method.
Impurity profile
The described set of identified and unidentified impurities present in a material: specified impurities with their own limits, any unspecified impurities against a general limit, and a total. It characterises the material's purity beyond the assay figure.
Loss on drying (LOD)
A gravimetric test reporting the percentage of mass a sample loses when dried under defined conditions. It captures water and other volatile matter together, unlike a specific water determination such as Karl Fischer titration.
Identification test
A test that confirms the material is the substance it claims to be, ideally by a method able to distinguish it from closely related substances, such as an infrared spectrum compared against a reference standard.
Acceptance criteria
The numerical limits, ranges or other measures a test result must meet for the material to conform: "not less than", "not more than", a range, or a defined qualitative outcome, as set by the governing specification.
Good distribution practice (GDP)
The quality standards governing wholesale distribution of medicinal products and materials: storage and transport conditions, traceability, documentation and controls that keep quality intact between manufacturer and recipient.
Supplier qualification
The documented process of evaluating and approving a supplier before relying on its materials and certificates: assessing quality history, auditing where risk warrants, agreeing specifications and reviewing performance at intervals.
Every one of these terms is something the COA Validator checks on a real certificate.