Thermoregulatory vs. event sweating--comparison of clinical methodologies, physiology and results.

OBJECTIVES: Although the mechanisms of sweating due to thermoregulation vs. stress are distinct, the antiperspirant industry focuses primarily on perspiration due to heat as their method of efficacy testing. To better understand the overall protection afforded by a 'Clinical Strength' over-the-counter antiperspirant product, we compare results from a standard hot-room study with results from two studies using the Trier Social Stress Test (TSST). METHODS: For each study, unscented antiperspirant was applied to one axilla, leaving the other untreated for internal control. The hot-room protocol involved a 40-min warm-up period with 2-20 min sweat collections at 100 ± 2 °F (35% RH). The TSST requires naïve subjects to give an impromptu speech and conduct mental arithmetic, with collections of sweat, heart rate and other biomarkers of stress before, during and after the event. RESULTS: During the TSST, heart rate and salivary cortisol data indicate significant emotional stress. Wetness results show that sweat was reduced by 69.4% in the hot-room study, compared with 83.7% and 89.3% reductions in the stress studies. CONCLUSION: We have found added value in investigating antiperspirancy from several causes of sweat production to give a more encompassing picture of the protection afforded by an antiperspirant product, specifically wetness protection from heat, activity and stress-induced sweat.

A regulator of ubiquitin-proteasome activity, 2-hexyldecanol, suppresses melanin synthesis and the appearance of facial hyperpigmented spots.

BACKGROUND: 2-Hexyldecanol has long been used in skin-care products, but has not previously been reported as an active ingredient for skin benefits. OBJECTIVES: To evaluate 2-hexyldecanol in in vitro and ex vivo systems and, if found to be active, progress it to topical clinical testing to determine effects on pigmentation in skin. METHODS: 2-Hexyldecanol was tested in melanocyte cell culture systems (B16 mouse melanoma cells and normal human melanocytes) for its effect on proteolytic activity and melanin production, in the absence and presence of the proteasome-specific inhibitor, MG132. It was further tested in a human skin explant model for its effect on melanin production. Lastly, topically applied 2-hexyldecanol was evaluated for its effect on the appearance of facial pigmentation in an 8-week, randomized, double-blind, vehicle-controlled, split-face incomplete block design study in Chinese women. RESULTS: In submerged cell culture, 2-hexyldecanol upregulated proteolytic activity and decreased melanin synthesis. These effects were antagonized by the proteasome-specific inhibitor MG132. MG132, tested in the absence of 2-hexyldecanol, increased melanin production. In a human skin explant model, topical 2-hexyldecanol suppressed the production of melanin vs. a vehicle control. In a human clinical study in Chinese women (n = 110 observations per test material), a 2-hexyldecanol-containing formulation significantly reduced the appearance of facial hyperpigmented spots vs. its control. CONCLUSIONS: These data indicate that regulation of proteasome activity is a viable target for control of melanin production, that 2-hexyldecanol upregulates proteasomal activity in melanocytes, and that topical 2-hexyldecanol reduces the appearance of hyperpigmentation.

Clinical studies of sweat rate reduction by an over-the-counter soft-solid antiperspirant and comparison with a prescription antiperspirant product in male panelists.

BACKGROUND: Individuals with axillary hyperhidrosis have much higher than average sweat rates and are often prescribed anhydrous aluminum chloride (AlCl(3)) solutions. Topical application of these solutions can be irritating to the skin, resulting in poor compliance and lower than desired efficacy. OBJECTIVE: Demonstrate the efficacy of an over the counter "clinical strength" soft-solid antiperspirant using a night time application regimen and compare to a prescription aluminum chloride (6.5%) antiperspirant using male panelists. METHODS: Gravimetric hot room efficacy testing (100 F and 35% Humidity) was performed comparing an over the counter soft-solid antiperspirant to placebo in a single test. Two separate gravimetric tests were placed comparing a prescription aluminum chloride (6.5%) antiperspirant to the same soft solid product using an intent to treat model. Skin irritation was assessed daily by a trained grader. RESULTS: Placebo testing resulted in 85% of panelists having a reduction in sweating rate greater than 50%. Comparison testing showed the over the counter soft solid reduced sweat rate by an average of 34% better than the prescription product while resulting significantly less skin irritation. CONCLUSIONS: Over the counter "clinical strength" soft-solid antiperspirants can be considered as an alternative treatment to aluminum chloride antiperspirants for the treatment of heavy sweating.