Instituto Valenciano de Microbiología
(IVAMI)

Masía El Romeral
Ctra. de Bétera a San Antonio Km. 0.3
46117 Bétera (Valencia)
Phone. 96 169 17 02
Fax 96 169 16 37
Email: 
www.ivami.com
CIF B-96337217

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Evaluation of the antimicrobial protection of a cosmetic: Preservative efficacy tests - Challenge test (UNE-EN ISO 11930: 2012 -formerly NF T75 611 standard- and European Pharmacopoeia) 

Test accredited by ENAC (National Accreditation Entity).

GLP certified.

Evaluation of the antimicrobial protection of a cosmetic product - Efficiency test (Challenge test) of preservatives accordingto UNE-EN ISO 11930: 2012 -formerly NF T75 611 standard-.Exposure tests are designed to determine the power of a preservative to prevent bacterial contamination during use, so they are forced tests for products that may pose a risk of infection for the user or product deterioration. Therefore, in exposure test (Challenge), an artificial contamination of the sample with 5 microorganisms is performed, using an standardized established concentration. The microorganism used in the efficacy tests are Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus brasiliensis. In the test, the cosmetic is inoculated with those microorganisms, and is followed by counting at 0 hours, 7, 14, and 28 days. The inoculated microorganisms must descend along the observation period and must reach a certain log reduction, to meet the criteria A or B set. For Aspergillus brasiliensis, should not increase at 28 days.

Evaluation of the antimicrobial protection of a cosmetic product - Efficiency test (Challenge test) of preservatives according to the European Pharmacopoeia. Exposure tests are designed to determine the power of a preservative to prevent bacterial contamination during use, so they are forced tests for products that may pose a risk of infection for the user or product deterioration. Therefore, in the exposure test (Challenge), an artificial contamination of the sample with microorganisms is performed. The microorganisms used in the efficacy tests are Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus brasiliensis. The European Pharmacopoeia allows use other microorganisms considering that can represent potential contaminants to the product. For this, the cosmetic product is inoculated with the microorganisms mentioned, and is followed at 0 hours and at different time intervals depending of the product type and a final reading at 28 days. The inoculated microorganisms must descend along the observation period and must reach a certain log reduction, to meet the criteria A or B in the European Pharmacopoeia set for each product type (topical, oral, ophthalmic, etc.). Criteria A expresses the recommended maximum efficiency to be achieved. In justified cases where the criteria A can not be reached, for example for reasons of an increased risk of adverse reactions, the criteria B may be sufficient (satisfactory).