Studies on the cosmetic criteria of the hair after shampoo

Abstract

Synopsis An objectivised sensorial method for evaluating the effects of shampoos on the appearance and manageability of the hair is described. Two different shampoos for greasy hair were applied twice weekly for a period of 4 weeks to the right and left sides (split-head tests) of six subjects having greasy hair, the same shampoo being applied to the same side. A trained observer used a continuous rating scale to assess nine cosmetic parameters; overall assessments by observer and subjects were noted. Evaluations were made immediately after and at various intervals following shampoo. The data were presented in 'profile graphs' and evaluated statistically. Shampoo A was found to be significantly better (P < 0.05) than shampoo B for all parameters immediately after shampoo and for six parameters after 1 day. The differences between A and B were no longer significant after 2 days, and only marginal differences were noted after 3 and 4 days. Analysis of the results of forty additional split-head tests carried out with ten different shampoos revealed interdependence (P < 0.01) between some parameters. Our results show the elective action of shampoos on the cosmetic parameters, the duration and limits of this action, and the interdependence between certain parameters.

Chemistry and Technology of the Cosmetics and Toiletries Industry

“…Many test methods and protocols, covering many aspects of product performance, have been used [32,[106][107][108][109][110]. Although instruments can often be used to produce a quantifiable result, the substrate is not the same as hair growing on the head, and the conditions ofthe tests may be too far removed from real conditions of use.…”

Hair Research

“…On the other hand, when two shampoos are compared in half-head studies, a profile of performance can be constructed based upon assessing a battery of cosmetic parameters (Scandel et al 1979). Of course, our methods are quite different and we believe more realistic in that we collected sebum from the scalp and hair after shampooing in the conventional manner.…”