SILICONE EMULSIFIERS AND SUNSCREEN PERMEATION 517 from these formulations. Therefore, silicone emulsifiers should be carefully chosen in order to minimize sunscreen skin permeation from cosmetic products and to improve their safety. REFERENCES (1) B. K. Armstrong, A. Kricker and D. R. English. Sun exposure and skin cancer, Austral. J. Dermatol., 38, S16 (1997). (2) A. R. Young, J. M. Sheehan, C. A. Chadwick, and C. S. Potten, Protection by ultraviolet A and B sunscreens against in situ dipyrimidine photolesions in human epidermis is comparable to protection against sunburn, J. Invest. Dermatol., 115, 37-41 (2000). (3) V. Bissonauth, R. Drouin, D. L. Mitchell, M. Rhainds, J. Claveau, and M. Rouabhia, The efficacy of a broad-spectrum sunscreen to protect engineered human skin from tissue and DNA damage induced by solar ultraviolet exposure, Clin. Cancer Res., 6, 4128-4135 (2000). (4) S. D. Gettings, S. Azri-Meehan, J. L. Demetrulias, W. E. Dressier, G. B. Kasting, C. K. Kelling, and D. Howes, "The Use of In Vitro Skin Penetration Data in the Safety Assessment of Cosmetic Formu- lations," in Prediction of Percutaneous Penetration, K. R. Brain, V. J. James, and K. A. Walters, Eds. (STS Publishing, Cardiff, 1993), Vol. 3b, pp. 621-673. (5) C.G. Hayden, M.S. Roberts, and H.A. Benson, Systemic absorption of sunscreens after topical application, Lancet, 350, 863-864 (1981). (6) G.J. Nohynek and H. Schaefer, Benefit and risk of ultraviolet filter, Regulatory Toxicol. Pharm., 33, 285-299 (2001). (7) S. T. Butt and T. Christensen, Toxicity and phototoxicity of chemical sun filters, Radiat. Prot. Dosira., 91, 283-286 (2000). (8) J. Knowland, E. A. McKenzie, P. J. McHugh, and N. A. Cridland, Sunlight-induced mutagenicity of a common sunscreen ingredient, FEBS Lett., 336, 184-185 (1993). (9) K.A. Walters, K. R. Brain, D. Howes, V.J. James, A. L. Kraus, N.M. Teetsel, M. Toulon, A. C. Watkinson, and S. D. Gettings, Percutaneous penetration of octyl salicylate from representative sun- screen formulations through human skin in vitro, Food Chem. Toxicol., 35, 1219-1225 (1997). (10) R. Jiang, M. S. Roberts, N. Collins, and H. A. E. Benson, Absorption of sunscreens across human skin: An evaluation of commercial products for children and adults, Br. J. Clin. Pharmacol., 48, 635-637 (1999). (11) R. H. Guy and J. Hadgraft, Phycochemical aspects of percutaneous absorption and its enhancement, Pharm. Res., 5, 753-758 (1988). (12) B. W. Barry, "Vehicle Effect: What Is an Enhancer?" in Topical Drug Bioavailability, Bioequivalence, and Penetration, V. P. Shah and H. I. Maibach, Eds. (Plenum Press, New York, 1993), pp. 261-276. (13) A. Hoelgaard and B. Mollgaard, "Dermal Drug Delivery--Improvement by the Choice of Vehicle or Drug Derivative," in Advances in Drug Delivery Systems, J. M. Anderson and S. W. Kim, Eds. (Elsevier, Amsterdam, 1986), pp. 111-120. (14) P. Treffel and B. Gabard, "Vehicle Influence on the In Vitro Skin Penetration of Ultra-Violet Filters Used in Sunscreen Formulations," in Prediction of Percutaneous Penetration, K. R. Brain, V. J. James, and K. A. Walters, Eds. (STS Publishing, Cardiff, 1996), Vol. 4b, pp. 178-181. (15) B. Idson, Vehicle effects in percutaneous absorption, Drug Metab. Rev., 14, 207-215 (1983). (16) V. K. Gupta, J. L. Zatz, and M. Rerek, Percutaneous absorption of sunscreens through micro-Yucatan pig skin in vitro, Pharm. Res., 16, 1602-1607 (1999). (17) P. Treffel and B. Gabard, Skin penetration and sun protection factor of ultra-violet filters from two vehicles, Pharm. Res., 13, 770-774 (1996). (18) E. Kurul and S. Hekimoglu, Skin permeation of two different benzophenone derivatives from various vehicles, Int. J. Cosmet. Sci., 23, 211-218 (2001). (19) G. Dahms, Choosing emollients and emulsifiers for sunscreen products, Cosmet. Toiletr., 109, 45-54 (1994). (20) R. P. Stokes and B. L. Diffey, The water resistance of sunscreens and day-care products, Br. J. Der- matol., 140, 259-263 (1999). (21) A.J. Disapio and M. S. Starch, New silicones emulsifier technology, Cosmet. Toiletr., 96, 55-57 (1981). (22) A.J. Disapio and M. S. Starch, "Using Silicones in Topical Products," in Topical Drug Delivery For- mulations (Marcel Dekker, New York, 1990), pp. 389-409.

518 JOURNAL OF COSMETIC SCIENCE (23) (24) (25) (26) (27) (28) (29) (30) (31) P. Ashton, J. Hadgraft, and K.A. Walters, Surfactant effects in percutaneous absorption, Int. J. Pharm., 87, 265-269 (1992). E. S. Park, S. Y. Chang, M. Hahn, and S.C. Chi, Enhancing effect of polyoxyethylene alkyl ethers on the skin permeation of ibuprofen, Int. J. Pharm., 209, 109-119 (2000). A.M. Kligman and E. Christophers, Preparation of isolated sheets of human skin, Arch. DermatoL, 88, 702-705 (1963). J. Swarbrick, G. Lee, and J. Brom, Drug permeation through human skin. I. Effect of storage conditions of skin, J. Invest. Dermato/., 73, 63-66 (1982). R. L. Bronaugh and R. F. Stewart, Methods for in vitro percutaneous absorption studies. 111. Hydro- phobic compounds, J. Pharm. Sci., 73, 1255-1258 (1984). E. Touitou and B. Fabin, Altered skin permeation of a highly lipophilic molecule: Tetrahydrocan- nabinol, Int. J Pharm., 43, 17-22 (1988). L. G. Mueller, Novel anti-inflammatory esters, pharmaceutical compositions and methods for reducing inflammation, U.K. Patent, GB 2 204 869 A, Nov. 23, 1988. V.P. Shah, J. Elkins, S.Y. Lam, and J.P. Skelly, Determination of in vitro drug release from hydrocortisone creams, Int. J. Pharm., 53, 53-59 (1989). S. E. Cross, R. Jiang, H. A. E. Benson, and M. S. Roberts, Can increasing the viscosity of formulations be used to reduce the human skin penetration of the sunscreen oxybenzone?,J. Invest. Dermato/., 117, 147-150 (2001).