The Effect of a Shampoo to the Hair, Skin, and Hair Follicle (Human and Animal)

The effects of a commercial shampoo on hair, skin, and hair follicle were examined by the following three methods.1) The tension tests and microscopical observations were carried out to see the physical change of the hairs.2) The patch tests were made on healthy human skin.3) The histopathological observations were obtained after 24 hr-patch test on the skin of four kinds of animals (Guinea pig, rat, rabbit and pig).The results obtained were as follows : The shampoo showed no effect on the hair. No positive reactions were found in the human patch tests under 4 hrs application of the shampoo itself and 10 hrs application of 5% solution of the shampoo. As for the animal tests, little effects on the skin were observed at 10% level of treatment. Though, in case of shampoo itself, an irritative reaction was found on the epidermis of some kinds of animals, but no obvious change of hair follicles was observed.