SUMMARY
Based on the results of the microbiological research the necessity of introduction of a preservative into the gel with essential oils developed for treating diseases of the upper respiratory tract has been proven. The microbiological research has been conducted according to the conventional method of the SPhU with the gel samples, in which the following preservatives were added: sodium benzoate, methylparaben, the complex preservative “Germaben”, the complex of sodium benzoate with Nipagin in the ratio of 0.5:0.1. It has been found that all gel samples under study meet of the SPhU requirements for microbiological purity (according to the criterion “A” and “B”). While conducting the comparative analysis it has been determined that addition of the preservative complex of sodium benzoate with Nipagin in the ratio of 0.5:0.1 is the most effective.