Abstract: An in vitro model for evaluation of the anti-dandruff performance of hair care products was established.In this model,Malassezia was used as indicator bacteria with pig skin as substrate.This model includes the following steps:pretreatment of the substrate;inoculation of indicator bacteria;measurement of the bacteriostatic efficacy by plate contact method;calculation of the effective index P;evaluation of the anti-dandruff performance by the effective index P.Three kinds of anti-dandruff agent,BPT,ZPT and OCT were tested with the model.Results show that the order for antibacterial efficacy of the anti-dandruff agents with mass fraction range of 0.1%~2.0% is BPT>ZPT>OCT.Evaluation results of hair shampoo from commercial market show that:one displays no anti-dandruff efficacy;three displays medium anti-dandruff efficacy;two displays strong anti-dandruff efficacy.

Key words: anti-dandruff shampoo, Malassezia, in vitro model