SENSORY QUALITY 107 REFERENCES (1) H. Stone and J. L. Sidel, Sensory Evaluation Practices (Academic Press, San Diego, 1993), pp. 295- 304. (2) H. B. Heath, Source Book of Flavors (AVI Publishing Co., 1981), pp. 546-548. (3) J. S. Jellinek, The Use of Fragrance in Consumer Products (John Wiley & Sons, New York, 1974), pp. 146-154. (4) A.M. Munoz, G. V. Civille, and B. T. Carr, Sensory Evaluation in Quality Control (Van Nostrand Reinhold, New York, 1992), pp. 5-51. (5) C. Krueger, Color control in cosmetics, Cosmet. Toiletr., 96, 35-36 (1981). (6) H. R. Moskowitz, Product Testing and Sensory Evaluation of Foods (Food and Nutrition Press, 1983), pp. 567-584.

j. Soc. Cosmet. Chem., 45, 109-118 (March/April 1994) A two-stage method for the in vivo replication of human skin: Method refinement and application KIMBERLY L^FRENIERE and ROBERT DIFRUSCIA, DowBrands L.P., I603 Building, Midland, MI 48674 (K.L.F.), and Dow Chemical Canada, Inc., Vidal St. S., P.O. Box 3030, 63 Building, Sarnia, Ontario, N7T 7MI, Canada (R.D.F.). Received April 29, I993. Synopsis A two-step replication process that utilizes Reprosil and Spurr's embedding medium has been critically evaluated for use in the study of personal care products on human skin. The high dimensional stability of the Reprosil material makes collection of entire data sets possible. This is especially convenient in multiple- person studies, where all samples may be collected and processed together under similar conditions at a laterdate or be sent collectively to an independent testing laboratory. The replication process is particularly well suited for the replication of fine, delicate structures. Details of hair follicles and the surface of leaves were excellently reproduced. The replication process may be easily and conveniently applied to the study of effects of personal care products on human stratum corneum, as long as the identical testing site is utilized for before-and-after comparisons. INTRODUCTION The study of the effects of personal care products on human stratum corneum has been facilitated by replication of the in vivo state with subsequent topographical analysis by scanning electron microscopy (SEM). Indeed, in 1976, Garber (1) employed replication techniques with SEM to evaluate the effects of moisturizing soaps, abradent cleansers, moisturizing hand lotions, and other active ingredients on human stratum corneum. Garber employed an RTV-11 silicon resin to make the negative replica and a thermo- plastic resin that was either fine spray-dried or as-polymerized polyolefin "bead" poly- mer to make the positive impression. In 1979, Pameijer (2) evaluated the dimensional integrity of a variety of dental impression materials in combination with different negative impression materials. Pameijer concluded that the combination of Reprosil dental impression material and Spurr's low-viscosity embedding medium resulted in the best reproduction of detail, greatest versatility, and superior dimensional stability as compared to other materials tested. In this study, the suitability of the combination of Reprosil dental impression material and Spurr's low-viscosity embedding medium to the replication of human stratum corneum for the purpose of documenting the effects of personal care products was critically evaluated. Issues that include ease of application of 109