VITAMIN E METABOLISM 95 uate research fellowship to Ae-Ri Cho Lee from Senju Pharmaceuticals, Osaka, Japan, is gratefully acknowledged. REFERENCES (4) (5) (6) (7) (8) (9) (10) (ll) (12) (13) (14) (15) (1) H. M. Evans, O. H. Emerson, and G. A. Emerson, The isolation from wheat germ oil of an alcohol ot-tocopherol, having properties of vitamin E, J. Biol. Chem., 113, 329-332 (1936). (2) E. H. Grugen, Jr. and A. L. Tappel, Reaction of biological antioxidants: 111. Composition of bio- logical membranes, Lipids, 6, 147-148 (1971). (3) H. M. Tinberg and A. A. Barber, Studies on vitamin E action: Peroxidation inhibition in structural protein-lipid micelle complexes derived from rate liver microsomal membranes, J. Nutr. Res., 100, 413-418 (1970). D. Djerassi, L. J. Machlin, and C. Nocka, Vitamin E: Biochemical function and its role in cosmetics, Drug and Cosmetic Industry, 46 (March 1986). M. Kakimura and T. Matsuzawa, Percutaneous absorption of ot-tocopherol acetate, J. Vitaminol., 14, 150-159 (1968). G. J. Klein, Dermal penetration and systemic distribution of 14C-labeled vitamin E in human skin grafted athymic nude mice, Internat. J. Nutr. Res., 59, 333-337 (1989). R. J. Scheuplein, Mechanism of percutaneous absorption: 1. Routes of penetration and influence of solubility, J, Invest. Dermatol., 45, 334-346 (1965). J. G. Bieri and R. P. Evarts, Tocopherols and polyunsaturated fatty acids in human tissues, Am. J. Clin. Nutr., 28, 712-720 (1975). J. G. Bieri and T. J. Tolliver, On the occurance of ot-tocopherol quinone in rat tissue, Lipids, 16, 777-779 (1981). H. E. Gallo-Torres, Intestinal absorption and lymphatic transport of dl-3,4-[•H]2-ot-tocopheryl nic- otinate in the rat, Internat. J. Vit. Res., 40, 505-513 (1970). J. lmai, M. Mayashi, S. Awazu, and M. Hanano, Solubilization of dl-ot-tocopherol by bile salts, polysorbate and egg lecithin. Chem. Pharm. Bull., 3, 4077-4082 (1983). K. Tojo, C. C. Chang, U. Doshi, and Y. W. Chien, Stratum corneum reservoir capacity affecting dynamics of transdermal drug delivery, Drug. Dev. Ind. Pharm,, 14, 561-572 (1988). H. E. Gallo-Torres, "Blood Transport and Metabolism," in Vitamin E.' Comprehensive Treatise, L. J. Machlin, Ed. (Marcel Dekker Inc., New York, 1980). C. D. Yu, Prodrug-based topical delivery: Simultaneous skin transport and bioconversion. Ph.D. thesis, The University of Michigan (1978). A. R. C. Lee, Percutaneous absorption and bioconversion of a provitamin for vitamin C and exper- imental and mathematical study on simultaneous diffusion and bioconversion, Ph.D. thesis, Rutgers- The State University of New Jersey (1990). (16) T. Shiratori, Uptake, storage and excretion of chylomicra-bound [•H]-tx- tocopherol by the skin of the rat, LiJ• Sciences, 14, 29 (1979).

j. Soc. Cosmet. Chem., 47, 97-107 (March/April 1996) Influence of formulation type on the deposition of glycolic acid and glycerol in hairless mouse skin following topical in vivo application M. OHTA, C. RAMACHANDRAN, and N. D. WEINER, Cosmetics Laboratory, Kanebo Ltd., Odawara, Kanagawa, Japan (M. O. ), and College of Pharmacy, University of Michigan, Ann Arbor, MI 48109-1065 (C.R., N.D.W.). Received December 1995. Synopsis The kinetics and extent of uptake of glycolic acid and glycerol in various strata of hairless mouse skin following topical in vivo application of several glycolic acid and glycerol formulations were determined. The formulations tested included an aqueous solution, a 30% propylene glycol (PG) aqueous solution, an oil-in-water (O/W) emulsion, a water-in-oil (W/O) emulsion, and two nonionic liposomal systems. The two nonionic liposomal formulations were prepared from: (i) glyceryl dilaurate, cholesterol, and polyoxyethyl- ene-10-stearyl ether (Non-1) and (ii) glyceryl distearate, cholesterol, and polyoxyethylene-10-stearyl ether (Non-2). Each of the test formulations was applied to the skin surface, and after one hour the formulations were removed by swabbing. Deposition profiles in the various strata were then monitored at 0, 1, 2, 4, and 8 h after removal of the formulation. The amounts of glycolic acid in the living skin strata at the end of the 1-h application period (0 hour time point) were in the order: Non-1 = Non-2 = aqueous solution = O/W emulsion = W/O emulsion 30% PG solution. The amounts of glycolic acid at the 8-h time point were in the order: Non-1 = Non-2 = O/W emulsion = W/O emulsion aqueous solution = 30% PG solution. The amounts of glycerol in the living skin strata at the end of the l-h application period were in the order: Non-2 = Non-! O/W emulsion = aqueous solution = 30% PG solution W/O emulsion. At 8 h, the amounts of glycerol in the living skin strata were in the order: Non-2 Non- 1 O/W emulsion = aqueous solution = W/O emulsion 30% PG solution. Although both glycolic acid and glycerol are hydrophilic, systemic absorption of glycolic acid was higher than that of glycerol. The Non-2 liposomal formulation appears to be the most efficient of all the formulations tested, since it delivered higher amounts of glycolic acid and glycerol into the stratum corneum and the living skin strata while retarding systemic absorption. INTRODUCTION Glycolic acid and glycerol are small water-soluble molecules that are widely used in cosmetic formulations to improve moisturization and appearance of skin. Glycerol is one of the most commonly used humectants in cosmetics (1). Glycolic acid is reported to smooth the skin's surface and create a more uniform skin tone (2,3). Although the mechanisms of therapeutic action of glycolic acid still remain unknown, it has been 97