Comparison between the efficacy of 89.5 % 1-propanol in shorter application times and the reference method of the DGHM for skin antisepsis,Vergleich der Wirksamkeit von 89,5 % 1-Propanol bei kurzen Anwendungszeiten mit dem Referenzverfahren der DGHM-Methode für die Hautantiseptik

Background: In Germany skin antiseptics are considered to be effective on sebaceous-rich skin sites if an equal effectiveness is demonstrated compared to the reference method (RM) of the German Society for Hygiene and Microbiology (DGHM); 10 minutes application time; 70 % 2-propanol. In a previous study we were able to show that 89.5 % (V/V) 1-propanol is more effective than 70 % 2-propanol [1]. Therefore we investigated in vivo if the efficacy of 89.5 % 1-propanol is non-inferior compared to the RM in shorter application times. Methods: The efficacy of 89.5 % 1-propanol at 4, 3, 2 minutes as well as 1 minute application time was determined at the forehead, the abdomen, the upper back and the lumbar area compared to the RM. Quantification of the skin flora was carried out according to the standard test method of the DGHM. Statistical analysis was carried out by non-inferiority testing. Results: 89.5 % 1-propanol showed non-inferiority to the RM at 3 minutes application time at all sites, and it was sometimes even superior. The lowest log10-reductions were found at the forehead; at one minute application time 89.5 % 1-propanol showed non-inferioriority [log₁₀-reduction; 1-propanol: 1.24 ± 0.77; RM: 1.51 ± 0.91]. At the upper back a minimum of 3 minutes application time was necessary to obtain non-inferiority; at the abdomen and the lumbar area 2 minutes were sufficient. Conclusion: Compared to the RM, equal reduction of skin flora was obtained with 89.5 % 1-propanol at 3 minutes application time. For establishment of an European standard test method for skin antiseptics, 1-propanol represents an interesting option for the reference method.