DETERMINATION OF ASCORBYL DIPALMITATE 367 JP, 59 10,505 (January 1982). Chem. Abstr., 100, 161685a (1984). JP, 59 10,505 (January 1982). Chem. Abstr., 101, 177273w (1984). JP, 59 65,007 (April 1984). Chem. Abstr., 101, 116584b (1984). JP, 60 78,912 (May 1985). Chem. Abstr., 103, 109772z (1985). JP, 60 23,307 (February 1985). Chem. Abstr., 103, 27082k (1985). JP, 61 100,509 (May 1986). Chem. Abstr., 105, 102354x (1986). (5) K. Yamaoka, M. Matsui, Y. Saito, and T. Sato, Effect of ointments and ointment bases on stability of ascorbic acid dipalmitate, Chem. Abstr., 97, 60908q (1982). (6) T. S. Vicente, E. H. Waysek, and W. M. Cort, Determination of ascorbyl palmitate by HPLC, JAOCS., 62, 745-747 (1985). (7) C. Inagaki, C. Okita, and N. Arakawa, Vitamins (Japan), 47, 229-232. Chem. Abstr., 79, 29188j (1973). (8) H. Tanaka and Y. Histani, Ester of ascorbic acid with higher fatty acid, Chem. Abstr., 68, 96104q (1986). (9) Chem. Abstr., 66, 7965 lg (1967). Chem. Abstr., 67, 34067a (1967). Chem. Abstr., 68, 16170v (1968). Chem. Abstr., 72, 65444d (1970).

j. Soc. Cosmet. Chem., 41, 369-378 (November/December 1990) Use of a chromameter in assessino the efficacy of anti-irritants and tannino accelerators N. MUIZZUDDIN, K. MARENUS, D. MAES, and W. P. SMITH, Estee Lauder Laboratories, 125 Pinelawn Road, Melville, NY 11747. Accepted October 24, 1990. Synopsis The chromameter is a tool for precise and objective assessment of surface color. Data output, in the form of the L* a* b* color coordinate system is used for different studies pertaining to skin color. L* values (darkness/lightness) are useful in evaluating and quantifying the tanning response. The a* values (red/ green) are valuable for quantifying the degree of erythema. We have found a highly significant (p = 0.0002) correlation between instrumental readings and visual evaluation of skin color response. In studies involving skin tanning, combination of the L*, a*, and b* values were studied. We conclude that L* values provide an objective and repeatable measure of skin darkening however, for a complete picture of the tanning response, AE* could be calculated. For studies involving skin irritancy, the a* value is used to quantify erythema. The resolution of the data is high enough to allow for discrimination and statistical confirmation of responses that cannot be reliably determined by simple visual assessment. INTRODUCTION Erythema and pigmentation are typical responses to ultraviolet radiation (1). The de- tection of visible change in skin color is affected by several unrelated factors, such as viewing geometry, ambient illumination, color of unexposed surrounding skin, and the experience and visual acuity of the observer (2). Instrumental objective methods allow for accurate, repeatable, and unbiased quantifica- tion of skin color and any change therein. The Minolta Chroma (Reflectance) Meter described by Babulak et al. (1986) (3) is a portable, noninvasive instrument that quickly and easily quantifies surface color. Data output is in various forms, of which a* values and L* values allow for simple quantification of surface redness and darkness/lightness. This monograph describes the objective measurement of the cutaneous response to various stimuli and compares this with information obtained from conventional subjec- tive visual estimations. 369