Cetylpyridinium-chloride (CPC) and Miramistin (MST) compared to established antiseptics under protein challenge in-vitro - evaluating alternative agents for wound cleansing

Background: Due to rising numbers microbial resistance to established antibiotics and first described tolerance developments for local wound antimicrobials a continuous need for alternative antimicrobial agents exists. Due to complex conditions in the microenvironment of especially chronic wounds, such as high protein levels, novel antimicrobials need to meet advanced requirements. Aim: Compare the antimicrobial efficacy of Cetylpiridinium-chloride (CPC) and miramistin (MST) to established antimicrobials under protein-challenge in-vitro. Methods: Antimicrobial activity of octenidin-dihydrochloride, povidon-iodine, polyhexamethylene-biguanide hydrochloride, chlorhexidine, cetylpiridinium-chloride and Miramistin after 0.5, 1, 3, 5 and 10 min of exposure against S. aureus, P. aeruginosa, E. coli, E. faecium and C. albicans was tested, using a quantitative suspension method with either 0.3% or 3% bovine albumin challenge, based on DIN EN 13727 (‘Chemical disinfectants and antiseptics - Quantitative suspension test for the evaluation of bactericidal activity in the medical area - Test method and requirements (phase 2, step 1)’). Results: CPC and MST demonstrated no inferiority to the established agents in-vitro. Especially CPC showed equal reduction rates as octenidin and povidon-iodine and achieved significantly higher reduction rates within shorter exposure times than polyhexanide and chlorhexidine (p ≤ 0.01) for S. aureus, P. aeruginosa, E. faecium and C. albicans. Both agents demonstrated no significant loss of efficacy under high protein-challenge (3% albumin). Conclusion: In terms of antimicrobial activity cetylpyridinium-chloride and miramistin proved to be at least equally effective as established agents. No protein error was detected in the tested concentrations. More complex in-vitro assays and comprehensive in-vivo and clinical studies will be needed to determine their clinical value.