Determination of the optimal concentration of the thyme essential oil in a cosmetic cream for the treatment of skin diseases

Aim. To determine the optimal concentration of the thyme essential oil in the cream for the treatment of scalp diseases as part of the first stage of the development of the composition of this remedy. Materials and methods. The study object was model ointment compositions on the vaseline-lanolin base with different concentrations of the thyme essential oil. The antimicrobial and antifungal activities of the essential oil components were determined in the microbiological studies using agar diffusion. The reliability of the effect of the concentration of the thyme essential oil on the microbiological activity was determined by the method of mathematical planning of the experiment with a repeated number of tests. Results and discussion. Using Duncan’s multiple rank test, the ointment compositions with different content of the thyme essential oil (0,5 %, 1 %, 2 %, 3 %, 5 %, 7 %, 10 %) made on a vaseline-lanolin base (7 : 3) were ranked by the effect of the concentration of the thyme essential oil on the microbiological activity. According to the results obtained, the best indicators of the microbiological activity were observed in the samples containing 10 %, 7 % and 5 % thyme essential oil, and they had practically the same activity of their concentrations. In order to save the thyme essential oil, it was decided to focus on its minimum concentration (5 %), which provided the maximum antibacterial effect. Conclusions. The results of the studies allowed us to state the reliable effect of the concentration of the thyme essential oil on the microbiological activity of the ointment. The optimal concentration of the thyme essential oil, which is 5 %, has been determined. It will be used in the future to develop the optimal composition of a cosmetic cream.