Furthermore, we sought to clarify one of the mechanisms
by which skin penetration of SG with O/W emulsions increases
more than when the oil vehicle is used. The influence
of skin hydration on the skin penetration of DiI by using an
oil suspension of DiI and water was assessed. YMP skin was
pretreated with water before the application of a DiI suspension.
Figure 5 shows CLSM images of cross-sections of YMP
skin after the application of a DiI suspension (a) and a DiI
suspension with water pretreatment (b). The amount of DiI
that penetrated the skin after pretreatment with water was
more than that after application of a DiI suspension alone.
This indicated that hydration of the skin increases the skin
penetration of DiI