Impact of Daily Antiperspirant Use on the Systemic Aluminum Exposure: An Experimental Intervention Study.

BACKGROUND AND OBJECTIVES: Adverse health effects such as neurotoxic and carcinogenic effects through aluminum from cosmetic products have been repeatedly discussed. The dermal uptake and impact on the systemic aluminum load is still poorly understood. Therefore, we investigated the effect of daily antiperspirant use on the systemic aluminum load under real-life conditions. METHODS: 21 healthy subjects meeting certain selection criteria to ensure a low systemic aluminum background load were asked to use a commercial aluminum-containing antiperspirant for 14 days. A questionnaire enquired about shaving habits and other sources of aluminum. Aluminum levels were measured before and after the exposure in 24-h urine and plasma using atomic absorption spectroscopy. Urine samples (n = 6) with <700 mg/day creatinine excretion or more than 30% difference in 24-h creatinine excretion were excluded from further analysis. RESULTS: No significant increase in plasma aluminum concentration or total excreted aluminum per day before and after exposure was measurable. No sample exceeded the reference values of the general population (maximum: 9.42 µg/g creatinine and 2.1 µg/L plasma). Shaving habits did not have a significant influence on the systemic aluminum load. Also, no correlation between the total amount of antiperspirant applied and the systemic aluminum level could be demonstrated. CONCLUSIONS: No measurable contribution to the overall systemically available aluminum load due to daily use of an antiperspirant for 14 days could be shown, but real-life data concerning long-term use or higher concentrations are still lacking. Considering toxicological occupational exposure data, adverse neurotoxic changes are unlikely in the case of urinary excretion of <50 µg aluminum/g creatinine (= no observed adverse effect level), even following long-term exposure.

Particle Size Distribution Analysis of OTC Aerosol or Powder Drug Products With Potential for Inadvertent Inhalation Exposure to Consumers.

The potential for inadvertent inhalation of over-the-counter (OTC) aerosol/powder drug products for topical application requires understanding of the characteristic size distributions of the airborne particles or droplets generated when these products are used as per the directions on the product label. Particle/droplet size is an important factor in determining the depth of particle penetration into the respiratory system after inhalation. Because particles penetrating beyond the larynx into the lung may lead to adverse respiratory effects, OTC aerosol or powder drug product particle size distribution is important to characterize. In this study, laser diffraction was used to analyze the particle size distribution of 32 currently marketed OTC drug products as emitted after actuation or air dispersion from their final package. Among the products surveyed were sunscreens, antiperspirants, topical analgesics, skin protectants, and acne products. The results may be useful to the U.S. Food and Drug Administration in its mission to protect as well as promote public health.

Shaving effects on percutaneous penetration: clinical implications.

CONTEXT: Human/animal shaving biology. OBJECTIVE: To assess the effect of shaving on percutaneous penetration and skin function. METHODS: We screened 500+publications in Pub Med, Scopus, Cochrane Library and pertinent journals out of which only 17 were deemed relevant. Terms for searches included shaving and skin, percutaneous penetration and shaving, skin absorption and shaving, absorption of dyes and shaving, skin penetration, effects of shaving and absorption, shave and dyes, axillary shaving and stratum corneum, shaving and breast cancer, shaving and infections, etc. RESULT: Shaving appears to have an exaggerated effect on percutaneous absorption; however, some studies do not support this evidence. CONCLUSION: Shaving enhances percutaneous penetration of some chemicals; however this effect is species and chemical specific. Further investigations of chemicals of varying physio-chemical properties are mandated before a generalized theory can be promulgated.

In vitro study of percutaneous absorption of aluminum from antiperspirants through human skin in the Franz™ diffusion cell.

Aluminum salts such as aluminum chlorohydrate (ACH) are known for use as an active antiperspirant agent that blocks the secretion of sweat. A local case report of hyperaluminemia in a woman using an aluminum-containing antiperspirant for 4 years raises the problem of transdermal absorption of aluminum (Al). Only a very limited number of studies have shown that the skin is an effective barrier to transdermal uptake of Al. In accordance with our analytical procedure, the aim of this study with an in vitro Franz™ diffusion cell was to measure aluminum uptake from three cosmetic formulations of antiperspirant: the base for an "aerosol" (38.5% of ACH), a "roll-on" emulsion (14.5% ACH), and a "stick" (21.2%), by samples of intact and stripped human skin (5 donors). The Al assays were performed by Zeeman Electrothermal Atomic Absorption Spectrophotometry (ZEAAS). Following contacts lasting 6, 12 and 24h, the Al assays showed only insignificant transdermal absorption of Al (≤0.07% of the quantity of Al deposited) and particularly low cutaneous quantities that varied according to the formulations (1.8 µg/cm² for "aerosol base" and "stick" - 0.5 µg/cm² for the "roll-on"). On stripped skin, for which only the "stick" formulation was tested, the measured uptake was significantly higher (11.50 µg/cm² versus 1.81 µg/cm² for normal skin). These results offer reassurance as regards to the use of antiperspirants for topical application of ACH-containing cosmetic formulations on healthy skin over a limited time span (24h). On the other hand, high transdermal Al uptake on stripped skin should compel antiperspirant manufacturers to proceed with the utmost caution.