248 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS suggest that it is possible to prepare membranes from simple synthetic lipids that are capable of modeling skin permeation characteristics. ACKNOWLEDGMENTS We wish to acknowledge Parrums Christian Dior and Liposome Technology, Inc., for support of this project. REFERENCES (1) D. Kittayanond, C. Ramachandran, and N. Weiner, Development of a model of the lipid constituent phase of the stratum corneum: I. Preparation and characterization of "skin lipid" liposomes using synthetic lipids. J. Soc. Cosmet. Chem., 43, 149-160. (2) C. M. Gary-Bobo, R. Dipolo, and A. K. Solomon, The role of hydrogen bonding in non electrolyte diffusion through dense artificial membranes, Gen. Physiol., 54, 369-382 (1969). (3) R. Dipolo, R. I. Sha'afi, and A. K. Solomon, The transport parameters in a porous cellulose acetate membrane, J. Gen. Physiol., 55, 63-76 (1970). (4) G. L. Flynn and R. W. Smith, Membrane diffusion. III. Influence of solvent composition and permeant solubility on membrane transport, J. Pharm. Sci., 61, 61-66 (1972). (5) F. Bottari, G. DiColo, E. Nannipieri, M. F. Saeton, and M. F. Safarini, Release of drugs from ointment bases. II. In vitro release of benzocaine from suspension type aqueous gels, J. Pharm. Sci., 66, 926-931 (1977). (6) C. R. Behl, E. E. Linn, G. L. Flynn, C. L. Pierson, W. I. Higuchi, and N. F. H. Ho, Permeation of skin and sechar by antiseptics. I: Baseline studies with phenol, J. Pharm. Sci., 72, 391-396 (1983). (7) S. Tanaka, Y. Takashima, H. Murayama, and S. Tsuchiya, Studies on drug release from ointment. IV. Release of hydrocortisone butyrate propionate from topical dosage form to silicone rubber, Int. J. Pharm., 27, 20-38 (1985). (8) W. P. Smith, M. S. Christensen, S. Nacht, and E. H. Gans, Effect oflipids on the reaggregation and permeability of human stratum corneum, J. Invest. Dermatol., 78, 7-11 (1982). (9) W. R. Koch, J. L. Burns, and D. L. Bissett, Preparation and characterization of a reconstituted stratum corneum film as a model membrane for skin transport, Arch. Dermatol. Res., 280, 2152-256 (1988). (10) W. Abraham and D. T. Downing, Preparation of model membranes for skin permeability studies using stratum corneum lipids, J. Invest. Dermatol., 93, 809-813 (1989). (11) S. E. Friberg and I. Kayall, Water evaporation rates from a model of stratum corneum lipids, J. Pharm. Sci., 78, 639-643 (1989). (12) P. W. Hertz and D. T. Downing, Ceramides of pig epidermis: Structure determination,J. LipidRes., 24, 759-765 (1983). (13) G. E. Burch and T. Windsor, Diffusion of water through dead plantar, palmar and dorsal human skin and through toe nails, Arch. Dermatol., 53, 39-41 (1944). (14) G. L. Flynn, S. H. Yalkowsky, and T. J. Roseman, Mass transport phenomena and model: Theo- retical concepts, J. Pharm. Sci., 63, 479-509 (1974). (15) R. J. Scheuplein and I. H. Blank, Permeability of skin, Physiol. Rev., 51, 702-747 (1981). (16) C. Hansch, Ed. Comprehensive Medicinal Chemistry: The Rational Design, Mechanistic Study and Therapeutic Applications of Chemical Compounds, Vol. 6, Cumulative Drug Subject Index 2nd Drug Compendium, Pergamon Press, New York (1990). (17) P. M. Elias, Epidermal lipids: Barrier function and desquamation, J. Invest. Dermatol., 80, 445-495 (1983). (18) P.M. Elias, Epidermal lipids, membranes, and keratinization, Int. J. Dermatol, 20, 1-19 (1981). (19) G. Grubauer, K. R. Feingold, R. M. Harris, and P.M. Elias, Lipid content and lipid type as determinants of the epidermal permeability barrier, J. Lipid Res., 30, 89-96 (1989). (20) P. M. Elias, E. R. Cooper, A. Korc, and B. E. Brown, Percutaneous transport in relation to stratum corneum structure and lipid composition, J. Invest. Dermatol., 76, 297-301 (1981).

ARTIFICIAL MEMBRANES 249 (21) W. Abraham and D. T. Downing, Interaction between corneocytes and stratum corneum lipid liposomes in vitro, Biochim. Biophys. Acta, 1021, 119-125 (1990). (22) P. W. Wertz, D.C. Swartzendruber, D. J. Kitko, K. C. Madison, and D. T. Downing, The role of the corneocyte lipid envelopes in cohesion of the stratum corneum,J. Invest. Dermatol., 93, 169-172 (1989). (23) D.C. Swartzendruber, P. W. Wertz, D. J. Kitko, K. C. Madison, and D. T. Downing, Molecular models of the intercellular lipid lamellae in mammalian stratum corneum, J. Invest. Dermatol., 92, 251-257 (1989). (24) C. Surber, P. Wilhelm-Klaus, M. Hori, H. I. Maibach, and R. H. Guy, Optimization of topical therapy: Partitioning of drugs into the stratum corneum, Pharm. Res., 7, 1320-1324 (1990).