278 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS '• -- '•- •.• ' . - : •.• ' / ' :•l•.,":. ' e.: ..•z•_• - - - •.* - •. ,•..• • ..... .- ••- •.• •.. e . •. • . ... .. ' - ' /'7--5 , - :• - ., L • •. •-•- . ". • i * • • '• '.• '" ..... • • •.• • .... •.• .... ,r•. •½..• ½..,½• %, , c-' '.7 '-"----'":' "c ........ .. ... • •-.•.• ,- ,•, ..•.. •. '-½•. ',. -.• •7•T .: . .:. •"•Z'•.½ ..• . • 'z?.•½"•*'• .• ' • '•.• --' ' '---*-• • - - - • * • ,•'• . : . , ...... • . .. .. •.. . ...• . .. Figure 10. Light micrographs showing the bistological feature within the skin of Angora rabbits at various times •ter 24 br topical application of •C-•DO. A) intact skin, B) zero day, C) one day, D) three days, E) six days, F) ten days. The changes of acantbosis in the epidermis and edema and vasodilatation in the dermis were obse•ed DISCUSSION Whole body autoradiography is a useful method since it can visualize the behavior of an applied material in the body and its possible metabolic routes then estimated. Figure 13 from our previous paper (20) showed autoradiograms of percutaneously absorbed •4C-hexachlorophene where the isotope was accumulated in the liver and excreted through the gallbladder to the small intestine at 6 hr after topical application. Such a well absorbed material gives a clear autoradiographic feature. However it is not avail- able for the materials of low percutaneous absorbability as shown in Figure 1. Besides,

PERCUTANEOUS ABSORPTION OF COSMETIC OILS 279 100' I• o o •4C- I PM x---x "C-HDO •O I I 0 24 72 Time hours Figure 11. Recovery percentage of •4C-labelled oils injected intradermally, plotted against time 14C- I PM Solvent Petroleum ether - Benzene : 14C-HD O A Solvent Petroleum et h..er- Benzene •, F 0 • Figure 12. Scanning curves of thin layer radiochromatograms of extracts from skin specimens