(LR-015) Investigating the Antimicrobial Performance of a Novel Non-Woven PHMB Dressing of its Speed of Kill (SOK) performance from 15 minutes up to a 14-day period

Daniela Ciumac, phD – Senior Technologist, Advanced Medical Solutions; Alexis Harding, BSc Hons – Scientific Services Leader, Advanced Medical Solutions; Alex Lawton, BSc Hons – Senior Product Manager, Advanced Medical Solutions; Lynne Salmon, 34+ years experience within industry – Project Leader, Advanced Medical Solutions; Charis Saville, phD – Senior Scientist, Advanced Medical Solutions

Introduction: A high absorbing gelling fibre dressing composed of carboxymethylcellulose (CMC) fibres and Polyhexamethylene Biguanide (PHMB), has been developed by Advanced Medical Solutions Ltd (AMS). The product already demonstrates effective antimicrobial activity against a wide range of common wound isolates after a 7 day period. The ability of the dressing to have antimicrobial efficacy within a short amount of time i.e., 15 minutes and its ability to remain effective over an extended wear-time i.e., 14 days is crucial in providing beneficial outcomes in a clinical environment.

Methods: The antimicrobial properties of the dressing were assessed utilising a log reduction test, performed in accordance with AATCC TM-100 guidelines over short test timepoints ranging from 15 minutes to 48hrs and extended timepoints up to 14 days. The assessment was performed against clinically relevant wound microorganisms i.e. Pseudomonas aeruginosa, Methicillin resistant Staphylococcus aureus (MRSA). Simulated wound fluid was applied to dressings to replicate soiled wound conditions prior to inoculation of the dressings. Total viable counts (TVCs) were performed following incubation and processing of dressings, to demonstrate the products ability to reduce microbial load.

Results: The data successfully demonstrates the PHMB dressing to exhibit exceptional speed of kill performance, as well as maintaining antimicrobial efficacy over an extended wear time. Additionally, the PHMB dressing exhibited exceptional antimicrobial properties when compared against numerous non-woven silver products on the market.

Discussion: An effective in vitro test method has enabled the speed of kill properties and extended antimicrobial efficacy of the PHMB dressing to be assessed, with the data indicating the PHMB dressing to have an all-rounded antimicrobial effect from quick kill within 15 minutes to sustained kill at 14 days, to support the wound healing process.