Ex-Vivo Skin Model Testing of Antimicrobial Lotions or Sanitizers

Purpose of Test

The Ex-vivo skin model test a carrier-based test method used to screen antimicrobial lotions, handwashes or hand sanitizers for sanitizing efficacy or residual sanitizing efficacy. As an in-vitro adaptation of the ASTM E1174 method which is designed to clinically evaluate the effectiveness of handwashes, this study allows for quick screening of products using simulated-use procedures without the need for human volunteers.

Summary of Test

This method utilizes a synthetic skin substance (Vitro-Skin®) designed simulate the topography and physical characteristics of human skin. Carriers prepared from the Vitro-skin® are inoculated with test organisms of interest and are treated in a manner designed to simulate use of the handwash, lotion or sanitizer. Following treatment, the carriers are neutralized and quantitatively assayed for surviving test organism. The resulting plates are incubated, the number of survivors is enumerated and a percent reduction is determined as compared to an untreated population control. No regulated reduction limits exist for this method as the results are typically used during the formulation process. Typical test organisms utilized in this method include Staphylococcus aureus and Escherichia coli, Salmonella enterica, Serratia marcesens, MRSA and additional pathogens of clinical, occupational or household relevance.