174 JOURNAL OF COSMETIC SCIENCE (7) (8) (9) (lO) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) M. Walker, L. A. Chambers, D. A. Hollingsbee, and J. Hadgraft, Significance of vehicle thickness tO skin penetration of halcinonide, Int. J. Pharm., 70, 167-172 (1991). G. Levy, Kinetics of pharmacologic effects, C/in. Pharmao/. Ther., 7, 362-371 (1966). B. C. Lippold and H. Reimann, Wirkungsbeeinfiussung bei L6sungssalben durch Vehikel am Beispiel yon Methylnicotinat, Tell II: Beziehung zwischen relativer thermodynamischer Aktivit•it und Bio- verftigbarkeit: Penetrationsbeschleunigung und Entleerungseffekt, Acta Pharm. Techno/., 35, 136-142 (1989). C. S. Leopold and B. C. Lippold, Enhancing effects of lipophilic vehicles on skin penetration of methyl nicotinate in vivo, J. Pharm. Sci., 84, 195-198 (1995). C. S. Leopold and B. C. Lippold, A new application chamber for skin penetration studies in vivo with liquid preparations. Pharm. Res., 9, 1215-1218 (1992). C. S. Leopold, How accurate is the determination of the relative bioavailability of transdermal drug formulations from pharmacodynamic response data? Pharm. Acta He/v, (in press, 1998). B. C. Lippold and H. Reimann, Wirkungsbeeinfiussung bei L6sungssalben durch Vehikel am Beispiel yon Methylnicotinat, Tell I: Relative thermodynamische Aktivit•it des Arzneistoffes in verschiedenen Vehikeln und Freisetzungsverhalten, Acta Pharma. Technol., 35, 128-135 (1989). M. Bach and B. C. Lippold, Penetration enhancement and its quantification, Eur. J. Pharm. Biopharm. (in press, 1998). J. Crank, Mathematics of Diffusion (Oxford University Press, London, 1956). M. Bach and B. C. Lippold, Influence of penetration enhancers on the blanching intensity of beta- methasone 17-benzoate, Int._J. Pharm. (in press, 1998). B.J. Aungst, Structure/effect studies of fatty acid isomers as skin penetration enhancers and skin irritants, Pharm. Res., 6, 244-247 (1989). A. H. Ghanem, H. Mahmoud, W. I. Higuchi, P. Liu, and W. R. Good, The effects of ethanol on the transport of lipophilic and polar permeants across hairless mouse skin: Methods/validation of a novel approach, Int. J. Pharm., 78, 137-156 (1992). R. Kadir, D. Stempier, Z. Liron, and S. Cohen, Penetration ofadenosine into excised human skin from binary vehicles: The enhancement factor, J. Pharm. Sci., 77, 409413 (1988). M. Goodman and B.W. Barry, Action of penetration enhancers on human skin as assessed by the permeation of model drugs 5-fluorouracil and estradiol. I. Infinite dose technique,J. Invest. Dermatol., 91, 323-327 (1988). C. S. Leopold and B. C. Lippold, An attempt to clarify the mechanism of the penetration enhancing effects of lipophilic vehicles with differential scanning calorimetry (DSC), J. Pharm. PharmacoL, 47, 276-281 (1995).

j. Cosmet. Sci., 49, 175-181 (May/June 1998) The oreasiness of moisturizers: A methodological study GREGOR B. E. JEMEC and HANS CHRISTIAN WULF, Department of Dermatology D, Bispebjerg Hospital, University of Copenhagen, DK-2900 Hellerup, Denmark. Accepted for publication May 15, 1998. Synopsis The aim of this study was to investigate if simple blotting can be used to provide reproducible quantitative data on the amount of excess moisturizer. Simple blotting of excess moisturizer was studied, changing the volume applied, the time allowed for absorption (before blotting), the time allowed for blotting, the area studied, the region studied, the blotting pressure, and the type of blotting paper. The coefficient of variation was calculated for each parameter. A standardized procedure is described: application of 50 pl/25 cm 2 of moisturizer on volar forearm skin. After 20 minutes blotting was performed with a 25 cm 2 (5 by 5 cm) piece of ordinary filter paper with pores of medium size. Blotting was done for 120 seconds with firm pressure applied by a rubber-gloved hand. The method had a coefficient of variation of 23% and was significantly correlated to skin surface lipids as measured by the Sebumeter (p 0.0001). Different commonly used moisturizers, as well as a protective cream and a simple gel, were compared using the new method, and the results were found to be in accordance with the clinical impression of cream greasiness. It appears to be possible to quantify non-absorbed moisturizer on the skin surface with an accuracy similar to that of other biophysiological methods. This simple method offers an improved possibility to classify moisturizers ac- cording to cosmetic acceptability and to quantify absorption for a better assessment of relative moisturizer efficacy. INTRODUCTION Moisturizers contain varying amounts of water, which evaporate shortly after applica- tion, leaving a lipid residue (1). It is speculated that the cumulative effects of moistur- izers are due to the absorption of this lipid residue, while short-term effects are mostly due to simple hydradon by the water phase of the moisturizer. The effects of any moisturizer is, however, also determined by the actual pattern of use by the individual, i.e., how is it applied and in what context, e.g., before clothing, after bathing, etc. Little is known about this, but it is speculated that the most common practical use involves application immediately prior to dressing, i.e., that only a short time is available for absorption of the applied moisturizer. A considerable excess residue of moisturizer lipids are thus left to be absorbed by the clothes. This unabsorbed excess represents a measure of the greasiness of the moisturizer that may affect actual use and cosmetic acceptability. We therefore describe a simple method to study this problem. 175