198 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Percutaneous absorption or autoradiographic studies with y linolenic acid (12), perhy- drosqualene (18), or triglycerides (19) confirm that fatty acids can be fixed in the vi- cinity of the sebaceous glands. This may explain the localized effects of linoleic acid on the skin of EFA-deficient subjects. Linoleic acid quantities found in whole skin 24 h after a single application and 24 h after the last iterative application are comparable. Therefore iterative applications allow more probably a sustained resorption of linoleic acid at constant levels in the blood during the duration of successive treatments, while the reservoir effect remains un- changed. Thus the effect of topical application of linoleic acid may be modulated ac- cording to the administration procedure. Localized action may be attained with a single application, while systemic absorption will be promoted to a larger extent by means of iterative treatments. REFERENCES (1) R. B. Alfin Slater and L. After Good, Essential fatty acids re-investigated, Physiol. Rev., 48, 758-784 (1968). (2) C. Prottey, P. J. Hartop, and M. Press, Correction of the cutaneous manifestations of essential fatty acid deficiency in man by application of sunflower seed oil, J. Invest. Dermatol., 64, 228-234 (1975). (3) N.J. Lowe and R. B. Stoughton, Essential fatty acid deficient hairless mouse: A model of chronic epidermal hyperproliferation, Br. J. Dermatol., 96, 155-162 (1977). (4) C. Protrey, Essential fatty acids and the skin, Br. J. Dermatol., 94, 579-587 (1976). (5) V. Basnajake and H. M. Sinclair, "The Effects of Deficiency of Essential Fatty Acids Upon the Skin," in: Biochemical Problems ofLipids, G. Popjak and E. Lebreton, Eds. (Butterworth, London, 1956), pp 476-484. (6) D. N. Menton, The effects of essential fatty acid deficiency on the skin of the mouse, Am. J. Anat., 122, 337-356 (1968). (7) J. L. McCullough, S. H. Schreiber, and V. A. Ziboh, Cell proliferation kinetics of epidermis in the essential fatty acid deficient rat, J. Invest. Dermatol., 70, 318-320 (1978). (8) D. A. Van Dorp, "Essential f•tty acids and prostaglandins", 24th Int. Congress of Pure and Applied Chemistry, (Butterworth, London, 1974), Vol. 2, p 117. (9) U. M. T. Houtsmuller and A. Van Der Beek, Effects of topical application of fatty acids, Prog. Lipid. Res,, 20, 219-224 (1981). 10) C. Protrey, Investigation of functions of essential fatty acids in the skin, Br. J. Dermatol., 97, 29-38 (1977). 11) C. Protrey, P.J. Hartop, J. G. Black, and J. i. McCormack, The repair of impaired epidermal barrier function in rats by the cutaneous application of linoleic acid, Br. J. Dermatol., 94, 13-21 (1976). 12) M. Costedoat, S. Rolez, and J. Wepierre, Absorption et distribution de l'acide %linoleique •4C administr6 par voie percutan6e chez le rat et l'homme, Int. J. Cosmet. Sci., 3, 83-93 (1981). 13) A. Hoelgaard and B. Mollgaard, Permeation of linoleic acid through skin in vitro, J. Pharm. Phar- macol., 34, 610-611 (1982). (14) H. Schaefer and G. Stuttgen, Absolute concentrations of an antimytotic agent econazole, in human skin after local application, Arzneim. Forsch., 26, 432-435 (1976). (15) S. Siegel, Non Parametrics Statistics for the Behavioral Sciences, (Mc Graw-Hill Kogakusha, Ltd, London, 1956), pp 116-127. (16) C. F. H. Vickers, Existence of reservoir in the stratum corneum: Experimental proof, Arch. Derm., 88, 20-23 (1963). (17) J. Wepierre, M. Corroller, B. Dubuc-Renault, C. Berrebi, A. Rougier, and D. Dupuis, Distribution de l'acide lino16ique •4C dans la peau apres application par voie percutan& chez le rat hairless carenc6 en acides gras essentiels, 2nd European Congress of Biopharmaceutics and Pharmacokinetics, J. M. Aiache and J. Hirtz, Eds. (Clermont Ferrand, 1984), Vol. 2, pp 131-140. (18) J. Wepierre, L'imperm6abilit6 de la peau de la souris & l'6gard du perhydrosqual•ne triti6, Ann. Pharm. Fr, 25, 515-521 (1967). (19) M. Suzuki, K. Asaba, H. Komatsu, and M. Mochizuka, Autoradiographic study on percutaneous absorption of several oils useful for cosmetics, J. Soc. Cosmet. Chem., 29, 265-282 (1978).