ANTIPERSPIRANT ACTION OF ALUMINUM SALTS 365 STUDY 5. THE INFLUENCE OF SWEATING Those experienced in evaluating antiperspirants appreciate that the physiologic activity of the eccrine glands prior to, during or after the test is one of the most important sources of variable results. Reller & Luedders (13) obtained enhanced effects when the subjects were briefly sweated and then inactive while applying the antiperspirant. They reasoned that the sweat-filled ducts of nonsweating glands would provide a static medium for the diffusion of ions. METHODS Influence of sweating before and after application of aluminum chloride Once daily for two days, for 15-rain periods 5 x 5 squares of Webril saturated with a 20% aqueous solution of A1CI 3 ß 6H20 were applied to three sites on eight subjects. Scheduling was as follows: the first site was exposed in the morning and the subject placed in an environmental hot room at 55øC and 30% R.H., remaining there for 2 rain after the onset of sweating (monitored by the starch-iodine technique). After removal to a cool place, the second site was treated for 15 min. The third site was exposed in the afternoon and served as a nonsweating control, the subject having remained in a passive state for 2 hr before and afterwards. This sequence was repeated on the second day sweat suppression was assessed on day 3. Effect of scopolamine Six subjects had 20% A1CI 3 ß 6H20 applied via chambers for 3 hr to two sites on their volar forearms. Preceding this, one site was iniected intradermally with 0.1 ml of 0.001% scopolamine hydrobromide in saline. This results in a total block of sweat secretion in a 2-cm area for 4 to 6 hr. Anhidrosis was assessed 24 hr later. Application of aluminum chloride during sweating Profuse sweating was induced in three subiects in the hot box. Then Webril patches soaked in 20% A1C13 were occlusively applied to the forearms for 45 min. The subiects remained in the chamber during this time and, of course, became drenched with sweat. RESULTS 1) Two 15-min exposures daily without sweating (control) produced an average anhidrosis of 47.5% (+27%). When applications were made in the resting state after a short period of sweating, suppression increased to 62.5% (_ 20%). There was a decrease to 32.5% (___30%) when sweating was induced immediately after exposure to A1CI 3 (Figure 3). Only the difference between treatments before and after a short sweat stimulus was statistically significant (p 0.05). 2) Scopolaminization prior to the application of A1C13 had no effect on the degree of anhidrosis. 3) When aluminum chloride was applied while subjects were actively sweating the antiperspirant activity was completely nullified.

366 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 100- 75 Control Sweat ing Sweat ing Sweatincj prior to following during appl. appl. appl. Figure 3. The influence of sweating on anhidrosis prior to, during and after the application of aluminum chloride. COMMENT Reller & Luedder's concept (13) that the eccrine duct filled with sweat provides a continuous medium for the diffusion of metal salts into the eccrine duct was supported by our observations. Prior sweating, provided that the glands remain inactive during and after the aluminum exposure, sharply enhanced antiperspirant activity. Scopolominization had no effect. This was not altogether expected since aluminum needs an aqueous medium to penetrate deeply into the acrosyringium. Very likely, a 3-hr exposure to a concentrated solution held in a chamber provides the medium. It is still possible that open application to a drug-inactivated sweal gland might show a lessening of the inhibiting effect of aluminum salts. ACKNOWLEDGMENT We are thankful to Mrs. Helga H 31zle and Mrs. Janice Stebbins for their excellent technical assistance. REFERENCES (1) W. B. Shelley and H.j. Hurley, Studies on topical antiperspirant control of axillary hyperhidrosis, ,4cta Derm. Venerolog., 55,241-260 (1975).