Pharmaceutical Microbiology: Testing Overview

In short: Pharmaceutical microbiology laboratories may perform sterility tests, microbial detection and enumeration, endotoxin tests, environmental monitoring and assays that use microorganisms. The tests required for a product depend on its approved specifications and applicable compendial text; the chapter list below is a guide to common subjects, not a universal test panel.

Scope of pharmaceutical microbiology

WHO guidance describes pharmaceutical microbiology laboratories as covering activities such as sterility testing; detection, isolation, enumeration and identification of bacteria, yeasts and moulds; bacterial endotoxin testing; and assays that use microorganisms. The work may involve products, starting materials, water, surfaces, garments and the laboratory environment. WHO TRS No. 961, Annex 2, Introduction and scope (2011)

Common testing areas and references

USP <789>, Particulate Matter in Ophthalmic Solutions (2023), describes a physical particle-counting test; it is a related product-quality test, not a microbiological test. The European Pharmacopoeia’s 5.1.1, Methods of preparation of sterile products, concerns preparation of sterile products rather than a laboratory test. Use those topics only where the product and applicable requirements call for them. USP <789> (2023); Ph. Eur. 5.1.1 (12th Edition, Issue 12.3, 2026)

FDA’s publicly available Pharmaceutical Microbiology Manual states that it supports FDA Office of Regulatory Science analysts and supplements USP and applicable FDA references. It notes that it includes some rapid-screening techniques. In the public copy, Chapter 9 is Environmental Monitoring and Chapter 10 is Inspectional Guidance; the manual says to check FDA’s QMiS for the most current official copy. It should not be used as a substitute for the applicable compendium, approved method or current FDA guidance. FDA ORA.007, Revision 02, 25 August 2020

Example in-house criterion (not a pharmacopoeial requirement): maintain a controlled matrix that maps each product or sample type to its approved microbiological tests, applicable method and monograph, method-suitability evidence, and current laboratory procedure. Review the matrix when a product requirement or referenced standard changes.

Batch-record retention

When microbiology results form part of batch-associated production, control or distribution records, retain the records for at least one year after the relevant batch expiry under 21 CFR Part 211. For EU GMP batch documentation, retain it for at least one year after expiry or five years after Qualified Person certification, whichever is longer. Apply longer periods required by product-specific rules, local law or contract. 21 CFR §211.180(a), current eCFR; EU GMP Part I, Chapter 4, §4.11 (January 2011)

Related reading: antimicrobial effectiveness testing, pharmaceutical sterility testing, good microbiological laboratory practice and microbial culture management.

Frequently asked questions

Does every pharmaceutical product need every test in the table?

No. Select tests according to the product’s applicable monograph, approved specifications and regulatory requirements. The table is a topic overview, not a universal release-testing panel.

Is particulate-matter testing part of microbiology testing?

No. USP <789> is a physical test for particles in ophthalmic solutions. It can be relevant to product quality, but it is not a microbial test. USP <789> (2023)

Is FDA ORA.007 a compendial standard?

No. It is an FDA laboratory manual for Office of Regulatory Science analysts. Use the current official controlled copy and applicable compendial requirements for the work being performed. FDA ORA.007, Revision 02 (2020)

References

• World Health Organization. WHO good practices for pharmaceutical microbiology laboratories. WHO Technical Report Series No. 961, Annex 2, 2011, Introduction and scope and §2.2. Official WHO publication.
• United States Pharmacopeia. General Chapter <51>, Antimicrobial Effectiveness Testing (2017); <61>, Microbial Enumeration Tests (2024; official date 1 May 2025); <62>, Tests for Specified Microorganisms (2017); <71>, Sterility Tests (2017); <81>, Antibiotics—Microbial Assays (2023); <85>, Bacterial Endotoxins Test (2017); and <789>, Particulate Matter in Ophthalmic Solutions (2023). <51> · <61> · <62> · <71> · <81> · <85> · <789>.
• European Directorate for the Quality of Medicines & HealthCare. European Pharmacopoeia, 12th Edition, Issue 12.3, applicable from 1 July 2026: chapters 2.6.1, 2.6.12, 2.6.13, 5.1.1 and 5.1.3. See EDQM’s current harmonisation-status table and Issue 12.3 notice; use the current legally effective full text.
• United States Food and Drug Administration, Office of Regulatory Affairs. Pharmaceutical Microbiology Manual, ORA.007, Revision 02, 25 August 2020, Introduction and Chapters 9–10. Official FDA PDF.
• European Commission. EudraLex Volume 4, EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use, Part I, Chapter 4: Documentation, §4.11, revision 1, January 2011. Official Chapter 4 PDF.
• United States. Code of Federal Regulations, Title 21, Part 211, §211.180(a), General requirements, current eCFR, accessed 16 October 2026. Official eCFR text.