Abstract
In our previous report, we developed a method to predict the preservative effectiveness of cosmetics from a predictive formula on the basis of the Minimum Inhibitory Concentration (MIC). Using this method, we predicted the preservative effectiveness of approximately 500 cosmetics, which satisfied a specific condition, and inspected the accuracy of this method. Though these cosmetics had differences in ingredients, e.g., antibacterial ingredients, humectants, viscosity regulators, oils and fats, we confirmed that we could predict the preservative effectiveness of them by this method. The quantity of antibacterial ingredients in a cosmetic is decided by challenge tests of a series of the cosmetics which changes only the quantity of antimicrobial ingredients. To find the appropriate quantity, many examinations are needed. However, because an approximate value of antimicrobial ingredients can be calculated by this method, we can reduce the number of examinations and can develop a new product effectively.
