[In vitro virucidal activity of antiseptics and disinfectants. III. Dilution-ultrafiltration-reconcentration technic]

The method for in vitro investigation of virucidal activity of antiseptics (ATS) of disinfectants (DSF) using dilution-ultrafiltration-reconcentration includes two phases following contact of the virus with ATS or DSF: termination of antiviral activity by sudden cold dilution, and one or more filtrations on an immersible molecule separator designed to bring the tested agent's concentration below the cytotoxic level and to reconcentrate the treated viral suspension. Advantages of this technique are the following: precision of time of contact between virus and ATS or DSF, reconcentration of the viral suspension which partly offsets the termination dilution, relative simplicity, and study of true virucidal activity. Drawbacks are: inappropriateness for some agents such as povidone-iodine, and, in some instances, unreliability of immersible separators. Apart for those obtained with povidone-iodine, results are comparable to those yielded by simple dilution or gel filtration, particularly for glutaraldehyde, chlorhexidine and noxythiolin.