Evaluation of the antiseptic activity of 5% alcoholic povidone-iodine solution using four different modes of application: a randomized open-label study.

BACKGROUND: Before some invasive procedures, such as injections, surgical incision or intravascular catheter insertions, alcoholic antiseptics (e.g., alcoholic povidone-iodine (PVP-I)) are widely used to prevent infection. AIM: This randomized, open-label study investigated the impact of mode of application (which includes both application technique and volume) on the antiseptic activity of 5% alcoholic PVP-I solution. METHODS: Alcoholic PVP-I was administered to the backs of healthy adults using four modes of application: (A) concentric circle method, 3 mL; (B) concentric circle method, 10 mL; (C) back-and-forth friction method, 3 mL; (D) back-and-forth friction method, 10 mL. PRIMARY ENDPOINT: antiseptic activity of alcoholic PVP-I, assessed via change from baseline in log10/cm2 colony-forming units (cfu) count for total aerobic and facultative anaerobic bacteria. Safety was monitored. FINDINGS: A total of 113 healthy participants were screened; 32 were randomized. Alcoholic PVP-I showed significant antiseptic activity with all modes of application (P<0.001 for each), providing an overall mean decrease from baseline in cfu count of >3 log10/cm2 (P<0.001). Significantly greater efficacy was seen with back-and-forth friction (modes C and D) versus concentric circles (modes A and B): covariate adjusted change in log10/cm2 cfu count 0.22; 90% confidence intervals: 0.07, 0.37 (P=0.017). No safety issues were observed. CONCLUSIONS: Alcoholic PVP-I demonstrated high antiseptic activity for all modes of application. Greater efficacy was achieved with back-and-forth friction versus concentric circles, showing that application technique may influence antiseptic activity; these findings suggest that when comparing the efficacy of antiseptic substances (e.g., alcoholic PVP-I and alcoholic chlorhexidine), comparable application techniques should be used.