14 JOURNAL OF COSMETIC SCIENCE CONCLUSION The emulsion manufactured at room temperature has organoleptic characteristics similar to those of the emulsion prepared at elevated temperature, while its stability is slightly better, leading to the conclusion that the room-temperature preparation technique is preferable in silicone-based emulsions. ACKNOWLEDGMENT We thank Christine Marie Laurin for translating the original manuscript into English. REFERENCES (1) G. Dahms, Choosing emollients and emulsifiers for sunscreen products, Cosmet. Toi/etr. 109(11), 45-54 (1994). (2) D. T. Floyd, Formulation of sun protection emulsions with enhanced SPF response, Cosmet. Toi/etr. 112, 55-63 (1997). (3) 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. (4) J. Smid-Korbar, J. Krist, and S. Srcic, Polydimethylsiloxane oil in ointments, Pharm. J. Slovenia, 37, 86-90 (1986). (5) M. A. Ruiz, A. Hernandez, A. Parera, and V. Gallardo, Dimethylsiloxane polymers: Vaporization rate test/freezing temperatures,J. Soc Cosmet. Chem. 46, 175-180 (1995). (6) C. Cabeza, Derivados organomodificados de silicona. Formulaciones cosm6ticas en emulsiones. Elabo- raci6n de emulsiones en frio. Aplicaciones. NCP, 173, 17-24 (1990). (7) A.J. Disapio and M. S. Starch, New silicones emulsifier technology, Cosmet. Toi/etr. 96, 55-57 (1981). (8) P. Hameyer and C. Bould, Organosilicone W/O emulsifiers, Man•f Chem., 20, 23-25 (1990). (9) R. Franquesa et al., Estabilidad de medicamentos A.E.F.I. (1985). (10) B. Artalejo, C. Fauli, and A. Del Pozo, Preformulaci6n de emulsiones: Estudio conductim6trico, Ind. Farm. 7/8, 91-99 (1987). (11) C. Phyllis, Am. Perf•m. Cosmet., 4, 77 (1962).

j. Cosmet. Sd., 50, 15-22 (January/February 1999) A study of I-cyclodextrin-stabilized paraffin oil/water emulsions SERGE LAURENT, MICHEL SERPELLONI, and DANIEL PIOCH, UR Chimie-Technologie Laboratoire de Lipotechnie, Centre de Coopgration Internationale en Recherche Agronomiq/•e pour le Dgveloppement, B.P. 5035, F 34032 Montpellier (S.L., D.P.), and Roqz/ettes Fr•res, F 62136 Lestrein (M.S.), France. Accepted for publication December 15, 1998. Synopsis This paper reports a study of the liquid paraffin emulsions stabilized only by I3-cyclodextrin (IBCD), a starch derivative well known for its ability to form inclusion compounds with a wide range of molecules. The effects of IBCD, which is not a surfactant, on emulsions' stability under heat and centrifugation, was checked. From a rheological standpoint, the IBCD emulsions are characterized by a very high flow threshold. The formation of an inclusion compound in the emulsion is likely to occur because a precipitate is always observed, even at low IBCD concentrations in the aqueous phase. The low particle size of tinis precipitate might play a role in the stabilization of these emulsions. INTRODUCTION Since the late 1980s changing consumer habits and environmental awareness have induced an evolution of the marketing strategies for cosmetics and toiletries. [3-cyclo- dextrin ([3CD), an oligosaccharide synthesized through a biotechnological process (1) from starch, was proposed intensively in the patent literature as an alternative emulsifier for food and cosmetics (2-6). Unfortunately, the properties of the emulsions that have always contained several emulsifers were not developed in the patent and only a few scientific papers deal with this subject (7,8). Because of the complexity of such systems, there still remains a doubt about the type of activity of [3CD. However, due to important scientific work in the last twenty years about [3CD, it is well known for its remarkable ability to form inclusion compounds with a wide range of molecules (9). This interesting property is due to the cylindrical cavity in its toroidal structure, which can provide a hydrophobic environment for guest molecules (9). At the opposite pole, the external surface of [3CD toroid is hydrophilic. As a result of these interesting properties, the use of this starch derivative was proposed for protection and solubilization of active compounds such as flavors or pharmaceuticals (11,12). 15