Measurement Method of Efficacy of Antidandruff Cosmetics and Development of the New Active Commercial Proct

This work was initiated to determine the quantity of dandruff scales by measuring total nitrogen content which can be recalculated based on the amount of proteins. And the method involved the collection of dandruff with a newly designed system and rinsing the dandruff from the scalp. Using this method, we investigated the seasonal variations in dandruff during a 13 month period on 160 subjects under strict control. We also studied the turnover time of the stratum corneum of the scalp and found that it averaged 15.3 days for the dandruff subjects but 17.1 days for non-dandruff subjects.The newly synthesized vitamin E derivative, L-ascorbic acid dl-α-tocopherol phosphoric acid ester potassium salt (EPC) was proven to have moisturizing effects, free fatty acid formation-inhibiting activity, and an antioxidant property but no bactericidal activity. In addition, EPC normalized the turnover time of the scalp in 16 subjects who used the hairtonic containing EPC. We conducted a double-masked application study of our new antidandruff hair tonic containing EPC. The antidandruff effects of our product were statistically significant when compared with a placebo. Its antidandruff effect was superior to that of zinc pyrithione shampoo.