Virucidal Efficacy of Topical Skin Products Utilizing an Ex-Vivo Skin Model

Purpose of Test

This carrier based test method is to be used to evaluate the effectiveness of topical skin products against designated viruses following an in-vitro modification of test method ASTM E 1838 (Standard Test Method for Determining the Virus-Eliminating Effectiveness of Hygienic Handwash and Handrub Agents Using the Fingerpads of Adults) utilizing an ex-vivo skin model in lieu of human subjects. This virucidal test method is designed to be used as one stage in determining virucidal potential of liquid hand soaps, lotions, sanitizers or other skin products without the need for human subjects. This method utilizes a testing substrate that mimics the surface properties of human skin. Typical test organisms utilized in this method include Adenovirus, Coronavirus, Influenza viruses, Rhinovirus, Rotavirus and additional pathogens of clinical, occupational or household relevance.

Summary of Test

This method utilizes a synthetic skin substrate (Vitro-Skin®) which has been designed to simulate the topography and physical characteristics of human skin. Carriers prepared from the Vitro-skin® are inoculated with the test virus and the virus is dried. An aliquot of test substance is then inoculated onto the dried virus and the carriers are held for the requested exposure time at the requested exposure temperature. Following exposure, the virus-test substance mixture is neutralized, serial dilutions are performed and each dilution is assayed for viral infectivity by an accepted assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. The percent and log reduction in viral infectivity are calculated as compared to the corresponding virus control.