OIL FILMS AND MOISTURE ABSORPTION ON HAIR 145 CONCLUSIONS Treating hair fibers with various oils reduced the amount of moisture regain and the diffusion rates of moisture in the fibers. These reductions are caused solely by the layer of oil on the surface of the fiber acting as a barrier. We suggest that differences between various oil-treated samples result partly from the differences in the molecular structure of the oils and their penetration behavior into the hair. Increasing the thickness of the oil layer on the fiber surface increased moisture regain and decreased diffusion rates. However, removing coconut oil from the fiber surface reversed the changes caused by the thin oil films. Our results using the DVS method indicate that moisture sorption behavior is not influenced by the oil that has penetrated into the cortex. This might be due to the relatively small quantities of oil present in the fiber interior. Greater changes are observed with oil penetrated into the cuticle layers and retained on the surface. ACKNOWLEDGMENTS This study was carried out in conjunction with the TRI project "Analysis and Quanti­ fication of Hair Damage," supported by an international group of TRI corporate par­ ticipants. REFERENCES (1) A. S. Rele and R. B. Mohile, Effect of mineral oil, sunflower oil, and coconut oil on prevention of hair damage,]. Cosmet. Sci., 54, 175-192 (2003). (2) S. B. Ruetsch, Y. K. Karnath, A. S. Rele, and R. B. Mohile, Secondary ion mass spectrometric inves­ tigation of penetration of coconut and mineral oils into human hair fibers: Relevance to hair damage, ]. Cosmet. Sci., 52, 169-184 (2001). (3) S. B. Hornby, Y. Appa, S. Ruetsch, and Y. Karnath, IFSCC Magazine, 8, 99-104 (2005). (4) K. Keis, D. Persaud, Y. K. Karnath, and A. S. Rele, Investigation of penetration abilities of various oils into human hair fibers,]. Cosmet Sci., 56, 283-295 (2005). (5) S. P. Chahal, N. I. Challoner, and R. T. Jones, IFSCC Magazine, 3, 19-25 (2000). (6) Y. K. Karnath, A. J. Lyttle, S. B. Ruetsch, and C. Wilrich, "Moisturizing Effect of Haircare Products," Proceedings of XXIth IFSCC International Congress 2000, Berlin.

J. Cosmet. Sci.! 58, 147-155 (March/April 2007) Formulation, characterization, and efficacy of an adenosine-containing dissolvable film for a localized anti-wrinkle effect J. Y. LEGENDRE, I. SCHNITZLER, Q.-Y. LI, C. HAUSEN, M. HUART, G. S. LUENGO, M. L. ABELLA, and M. ROREGER, L'Oreal Recherche! 188-200 rue Paul Hochart! 94550 Chevilly-Larue U- Y.L.! M.L.A.)! and 1 av Eugene Schueller, 93601 Aulnay-sous-Bois (M.H.) G.S.L.), France and Skin Care Systems, Lohmannstrasse 2! 56626 Andernach! Germany (l.S., Q.-Y.L. 1 C.H., M.R.). Accepted for publication November 1, 2006. Synopsis A water-dissolvable film was developed to topically deliver adenosine for a localized anti-wrinkle effect. The polymers used to produce the film were cellulose derivatives. An aqueous mixture of the film components was made, coated on a liner, and then dried to form a solid film. No preservatives were added and the film was shown to be stable over time. The film quickly dissolves in water to form a uniform layer at the surface of the skin, as shown by scanning electron microscopy. The film layer can still be visualized on the wrinkle six hours after being applied on the skin. A randomized, placebo-controlled, investigator-blind study was conducted in female volunteers to assess the efficacy of the 1 % adenosine-containing dissolvable film. After three weeks and eight weeks, a twice daily application led to a significant decrease in the skin roughness parameters as observed using fast optical in vivo topometry (FOITS). These results demonstrate that water-dissolvable films may be used as novel, preservative-free, cosmetic delivery systems. INTRODUCTION Dissolvable, edible films have been used for years in the food industry as carriers for flavor or nutritional additives or as barriers for separation, protection, and preservation purposes (1). Usually, edible films are made of highly water-soluble polymers, such as polysaccharides or proteins (2) as well as film-forming materials such as lipids and resins or combinations of these (2,3). Recently, edible strips for breath freshening have been very successfully introduced on the market and are becoming increasingly popular. Indeed, dissolvable films can easily be carried everywhere by the consumer and represent a new type of user-friendly, single-dose formulation to administer various ingredients, ranging from food additives to over-the-counter drugs. We investigated solid, water-soluble films to deliver cosmetic ingredients to the skin. The goal of the present study was to formulate a film that can easily be dissolved with 147