Antimicrobial Activity of a New Aloe vera Formulation for the Hygiene of the Periocular Area

Purpose: The aim of this study was to evaluate the antimicrobial activity of a novel preservative-free lid wipe formulation containing Aloe vera gel and hyaluronic acid that is commercialized for the hygiene of the periocular area. Methods:In vitro susceptibility testing of the solution contained in wipes against bacteria and fungi commonly colonizing the periocular area, both reference strains and multidrug-resistant (MDR) clinical isolates, was assessed following the CLSI M07-A9 and M27-A3 broth methods, respectively. The solution was 2-fold serially diluted in broth from 25 μL (25% v/v) to 0.012 μL (0.012% v/v) in microtiter plates. Plates were incubated and minimal inhibitory concentrations (MICs) were read visually. The antimicrobial effectiveness test was performed by inoculating the wipe solution with microbial suspensions at the initial concentration of 105–106 CFU/mL, as recommended by the international Pharmacopoeias. At different time intervals, samples were tested for microbial count. Results: The MIC value of the solution ranged from 25% to 12.5% for bacteria and was 6.25% for Candida albicans. The MIC for MDR isolates was 12.5%. By assessing antimicrobial effectiveness, we found that the solution meets the criteria reported by the European Pharmacopoeia and United States Pharmacopeia for its preservative effect. Conclusions: This study demonstrates that the novel wipes herein tested possess antimicrobial activity against bacteria and yeast commonly found in the periocular area, and against MDR clinical isolates. The microbial death curves obtained following deliberate contamination of the wipe solution revealed potent bactericidal and fungicidal activity of the formulation.