USP <1227> - Validation of Microbial Recovery from Pharmacopeial Articles

What it says

This chapter provides guidance on validating the recovery of microorganisms from pharmacopeial articles, so that a product's own antimicrobial properties do not give a falsely low count or a false negative. It describes how to show that the method of sample preparation, such as dilution, neutralization, filtration or a combination, allows recovery of low numbers of test organisms.

Paraphrased for plain-language clarity. Always verify against the current published regulation text.

What it means in practice

• A product that kills or inhibits organisms can make a contaminated sample look clean, unless the test removes that effect.
• Recovery has to be shown for each product or product group, and again when the formulation changes.
• Neutralizers and diluents must themselves be shown not to be toxic to the test organisms.

What inspectors look for

• Whether method suitability was demonstrated for each product tested.
• Whether the validation was repeated after formulation or method changes.
• Whether the neutralization approach was shown to work.

Related regulations