PERCUTANEOUS ABSORPTION OF COSMETIC OILS 269 I PM m HDe GTO m Figure 1. Whole body autoradiograms showing the distribution of radioactivity in hairless mice at 48 hr after topical application of •4C-oil-containing hydrophilic ointments. No oils were penetrated into body organs. The radioactivities of oils were localized on the applied regions. The right of figure is head and the left is tail HDO. The silver grains were not observed in the skin even after 24 hr. It was thought to be absorbed little or at an extremely slow rate. From the results above, the absorbability of the oils was found reasonably in the following order from greatest to least: IPM, GTO, OD, DD and HDO. Therefore, percutaneous absorption on IPM as the highest penetrant and HDO as the lowest was then examined in Angora rabbits by means of microautoradiography more deeply, simultaneously with skin irritation potential by histological method.

Figure 2. •icro•utor•iogr•ms showing the •istribution topical •pplic•tion o[ •C-l•bcllc• oils. i) iPM, 2) GTO, •) OD, 4) DD, S) HDO •n• A) d hr, B) 24 hr (scc text) 270