This abstract presents of results of the study microbiological purity gel under the code name "Anticandid" based on substances derived 4H-pyrido[4',3':5,6]pyrano[2,3-d]pyrimidine derivatives with antifungal activity. The practical value and originality are concluded in the study the number of microorganisms in samples of gels by different methods. The research results showed the high quality of the samples in terms of "Microbiological purity."