Antimicrobial efficacy in vivo of a new formulation of 2-butanone peroxide in n-propanol: comparison with commercial products in a cross-over trial

Summary The use of hand rub to obtain maximum decrease in bacterial load is important because the reduction needed to avoid transmission is unknown. The monomer of 2-butanone peroxide is a peroxygen derivative with potential biocidal use in hospitals. The aim of this study was to compare the efficacy of hand rub with an alcoholic solution of peroxide 2-butanone versus five antiseptic products, against E. coli K12 (CECT 433) transient flora acquired by hand immersion in a broth culture following the UNE-EN-1500 standard. Isopropanol 60% (control) obtained 99.99% reductions, driving down the bacterial load from 10 6 cfu/mL in the initial inocula to 10 (99.99%), driving the initial inocula down to ≤100 cfu/mL, despite the low concentration (35%) of propanol in the solution. This novel peroxygen biocide offers high in-vivo cidal activity against acquired E. coli transient flora, offering an alternative to products with higher alcohol concentrations.