Abstract
Hair medulla is a porous structure at the centre of the hair, of which little is known, particularly its functions. We have shown that the structure of medulla can be altered by applying and penetrating into the hair, a formulation comprising a combination of specific components. Such a chemical treatment lends glossiness to the hair, making it aesthetically attractive. We call this process Hair Medulla Care. In this study, we investigated further by assessing the extent of penetrability of substances in relation to their chemical properties. The results showed that the Hair Medulla Care enhances penetration of all substances that we attempted, anionic, cationic and lipophilic fluorescent dyes. This finding can be applied to basic hair dyes, enabling them to penetrate deeply into the hair, creating deeper and more vivid colours. Its dyeing ability was far beyond what can be expected from conventional means. Furthermore, it allowed the infiltration of melanin into the hair, which was impossible until now. Thus, the procedure can deliver various substances which have different properties to the medulla and can be applied for various hair care and cosmetic products, such as damage care and perms, in addition to hair colours.
