Next, we examined whether SG applied in the oil phase
affected skin penetration by using the 3 types of LP with
HCO as an emulsifier (Table 1). Figure 3 shows the amounts
of SG that penetrated the skin from 3 different O/W emulsions
containing different types of liquid paraffin (LP-A,
LP-B, and LP-C). The amount of SG skin penetration differed
significantly between them (LP-A>LP-B>LP-C). The water
contained in the O/W emulsion evaporated on the skin, and
the oil phase remained on the skin surface after phase inversion.
Therefore, we also examined the skin penetration of the
oil phase of the O/W emulsion, and compared the emulsion
with the oil phase. SG penetration into the skin was enhanced
approximately 1.5-fold with the O/W emulsion, compared to
the oil phase. We observed a significant difference between
the O/W emulsion and the oil phase (Fig. 3)