SITE OF ALUMINUM ANTIPERSPIRANT ACTION 437 of Micropore Surgical Tape © (3M Co., St. Paul, Minnesota) to prevent inadvertent loosening. The patch remained in place for 22-24 hours. The antiperspirant test solutions were 20% aqueous ACH*, 10% aqueous AZAP**, and 8% aqueous A1C13 *•. Several additional subjects, serving as controls, were treated with distilled water and processed identically. The patch was removed in the morning of Day Ill at not less than four hours prior to further study. Using this treatment regimen, the maximum inhibition by the antiper- spirant test solution was insured, while sham inhibition, due to the process of occlusive application of a solution, was afforded time to dissipate. In the afternoon of Day Ill, the subject again entered the environmental chamber, and, as described above, photographs of the starch/castor oil/iodine-generated sweat pattern were taken after an initial 40-min period of acclimation to thermal stress. (Photographs were also taken after the subject had been under thermal stress for 50 and 60 minutes as well). The starch mixture was then removed and the subject returned to ambient temperature. Using cellophane tape, the stratum corneum layer of the antiperspirant-treated axillary test site was quickly stripped away, exposing the granular layer. The subject was then immediately thermally stressed for the third time and a series of post-stripping photo- graphs was taken in the usual manner. The number of functioning sweat glands, as evidenced by the individual black dots resulting from the reaction between the sweat droplets (water) and the starch mixture, was determined for each of the three periods--pre-treatment, post-treatment and post- stripping. The percentage of those sweat glands which were inhibited by the antiperspirant treat- ment but which were restored to function when the intracorneal segment of their ducts had been removed could then be calculated. For example, if the number of sweat glands observed before and after treatment was 100 and 20, respectively, and the number of glands observed after treatment and after stripping was 20 and 60, respectively, then: 60-20 100-20 40 inhibited glands restored 80 inhibited glands X 100 = 50% restoration. RESULTS For the participants in this study, the average density of eccrine sweat glands in the axilla was approximately 90/cm 2, but there was a considerable range (50-200 glands/ cm 2) among them. The effect of the overnight occlusive application of the three alu- minum antiperspirants, ACH, AZAP, and A1CI•, on axillary eccrine sweat gland func- tion was as follows. * Prepared from a 50% aqueous ACH solution obtained from Wickhen Products, Inc., Huguenot, New York. ** Prepared from the dry powder obtained from Wickhen Products, Inc., Huguenot, New York. *** Obtained as the reagent grade hexahydrate salt from Fisher Scientific Co.

438 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS ACH When 20% ACH was occlusively applied, approximately 90% of the treated sweat glands, on average, were inhibited. Tape stripping away the stratum corneum resulted in restoring to function an average of slightly more than one quarter of these inhibited sweat glands (Table I). AZAP Sweat gland function was again inhibited in 90% of the sweat glands treated with 10% AZAP. Removal of the intracorneal duct segment of these glands resulted in restoring more than 40% of them, on average, to a functional state (Table I). AICIs As with 20% ACH or 10% AZAP, the occlusive application of 8% A1CI• to axillary eccrine sweat glands caused nearly all (92%) of the glands to cease functioning. However, as had been observed previously in similar forearm studies, the number of sweat glands whose impaired excretory capability was restored upon removal of their intracorneal duct segment constituted a very small percentage of the total (Table I). For the subjects who served as controls, the number of active sweat glands observed in the test site before and after the occlusive application of distilled water, as well as after tape stripping, was essentially identical. Table I The Effect of Cellophane Tape Stripping on Axillary Eccrine Sweat Gland Function Following Occlusive Treatment with Aluminum Antiperspirants Median Treatment • + S.E. (Range) 20% ACH (N -- 10 Subjects) Percentage of glands inhibited Percentage of inhibited glands restored to firing 10% AZAP (N = 9 Subjects) Percentage of glands inhibited 91 q- 3 95 (84-100) 28+8 24 (4-85) 90 q- 3 93 (72-100) Percentage of inhibited glands restored to firing 41 q- 7 8% AICI• (N = 9 Subjects) Percentage of glands inhibited 36 (12-76) 92 q- 2 91 (84-100) Percentage of inhibited glands restored to firing 2+1 0.6 (0-9.3)