Preservative Efficacy Test - Eurofins Scientific
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Preservative Efficacy Test

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Preservative efficacy testing is required for the assessment of the antimicrobial preservation of multiple-use cosmetic and pharmaceutical products.

Clients may choose the challenge test to be conducted in accordance with the British Pharmacopoeia (BP), US Pharmacopoeia (USP), a combination of both, a client specific protocol or another nominated method.


Antimicrobial preservatives are added to products to prevent or limit microbial contamination, which can occur during normal conditions of storage and use.  The efficacy of an antimicrobial preservative may be enhanced or diminished by the active constituent of the preparation, or by the formulation in which it is incorporated, or by the container and/or closure being used as the final packaging material.

The test method must be qualified for the product under evaluation to ensure the correct diluent is used in assays for surviving microorganisms.

The product is inoculated with specified number of each challenge organism.  The inoculated product is held at room temperature for 28 days.  It is examined by the duplicate plate count method to determine the number of viable microorganisms which survive at each specified time interval.

All results are evaluated in accordance with the tabulated acceptance criteria of the relevant Pharmacopoeia’s or test protocols.


Validation: 50g or 50ml

PET: 150 – 200 g or 150 - 200 ml