Selection and Substantiation of Methods for Estimating the Consumer Properties of Cosmetic Products by Deodorant and Antiperspirant Effect. Part 2. Development of an Express Method for Estimating the Intrinsic Antimicrobial Activity of the Products

The intrinsic antimicrobial activity of personal care products against the sweat odor is a necessary element of their functional properties. To estimate this characteristic, two bacterial strains typical for the armpit zone were selected as test organisms: Corynebacterium stationis VKPM-V-10645 and Micrococcus luteus VKPM-V-7845 that demonstrated a sensitivity to all tested commercial deodorant/antiperspirant samples. An express method (a method of “rapid” microbiology) using a 0.03% water solution of 2,3,5-triphenyltetrazolium chloride (TTC) was suggested. The testing conditions were selected: the amount of test strain inoculum introduced into the reaction medium, as well as the amount and method of introducing a cosmetic product for significant accounting of the results after 3 h of incubation of the samples. This express method can be used for rapid estimation of antimicrobial activity and recommended for the analysis of large volume of objects, particularly, when searching or synthesizing new active biocidal ingredients and in large-scale testing of cosmetics against the sweat odor.