In this study, our aim was to study

In this study, our aim was to study the cosmetic samples that were used before and that have not an expiry date report, in case of microbial contamination and preservative activity. A total of 73 samples includ- ing 20 lipsticks, 20 eye shadows, 13 foundations and 20 eyelashes that were used before were studied. Microbial contamination was studied according to the guidelines of U.S. Food and Drug Administration (FDA) method: “Microbiological Methods for Cosmetics”. Among the samples, in 3 eyelashes, 3 eye shadows, 2 lipsticks and 2 foundations of 10 sam- ples microbial contamination were observed. In 5 samples total aerobic bacteria numbers were off the limits. Salmonella spp. and Pseudomo- nas aeruginosa were not observed but Candida spp., Staphylococcus aureus and E.coli that are not allowed to be found in cosmetics were determined.
Preservative activity was investigated with the Challenge Test. After a contact time of 0, 3, 7, 14, 21 and 28 days, cell viability was determined by the plate count method and a reduction in the number of each micro- organism of 99.9% by 7 days was required in order for the formulation to pass the test. After the challenge test the preservative activity of all the products was shown to be ineffective because the microbial growth was not limited with a reduction of 99.9%.