The primary active ingredients in deodorants and antiperspirants are antibacterial agents and aluminum compounds. Whereas such antimicrobials as ethanol, citricidal, triclosan, and zinc phenolsulphonate are effective in killing the bacteria associated with the formation of underarm odor, aluminum compounds such as aluminum chloride, aluminum chlorohydrate, aluminum sulfate, and aluminum zirconium glycine dissolve on the skin and hydrolyze in sweat ducts, thus preventing build-up of the sweat on which the bacteria feed.
One of the keys to a successful antiperspirant product is that its aluminum compound should be present at strong enough levels so as to prevent perspiration and yet not so strong that it irritates the skin. To achieve this balance, manufacturers calibrate the compound's acidity, which is the quality that makes it effective at blocking sweat ducts, with its base, the quality that neutralizes its potentially harmful effects. Early aluminum-chloride based antiperspirants suffered from just such an imbalance, not only causing skin rashes but also damaging clothing. The non-active ingredients present in deodorants and antiperspirants depend largely on the form of application the product takes. In the early years of their development, antiperspirants and deodorants were available primarily as creams, powders, or roll-ons. In 1965 the Gillette Company became the first manufacturer to produce an antiperspirant in an aerosol dispenser when it introduced Right Guard. By the late 1960s aerosol antiperspirants and deodorants stormed the marketplace. What gave the aerosol products their propulsion were fluorocarbons, which were favored for the soft dry spray they produced. However, in 1978 the U.S. government banned the use of fluorocarbons due to research that identified the gaseous compound as detrimental to the ozone layer of the earth. Manufacturers later replaced fluorocarbons with alternatives in aerosol products; however, negative publicity had a strong effect on the market. By 1982 U.S. sales of aerosol antiperspirants and deodorants dropped to a 32 percent share of the market from a high mark of 82 percent during the 1970s.
First formulated in 1934, solid stick products quickly filled the gap left by aerosols. They consisted of an active antiperspirant/deodorant ingredient suspended in a waxy base. Common base materials were stearyl alcohol, cetyl alcohol, hydrogenated castor oil, and glyceryl stearate. Base materials were blended with lubricating oils and emollients such as cyclomethicone, a volatile silicone compound.
The last two decades of the twentieth century saw new developments in the effectiveness of standard aluminum chlorohydrate and aluminum zirconium actives. Though chemically indistinguishable from their standard forms, the new actives, referred to as enhanced efficacy aluminum compounds, were processed so that they contained lower weight molecular polymers, a property that enabled them to provide sweat prevention for longer periods of time.
One of the key suppliers of materials to the antiperspirant and deodorant industry is the specialty chemical manufacturer Reheis Inc., a subsidiary of GenTek. Based in Berkeley Heights, New Jersey, Reheis produces a range of 45 to 50 aluminum compounds including aluminum chlorohydrates and aluminum zirconium chlorohydrates. The company played a major role in the research and development of aluminum compounds. Some of its products are Rezal 36 GP, Rezal 36 GP SUF, Reach 301, and Reach-AZP 908.
Other inactive ingredients in antiperspirants and deodorants are fragrances, colorants, and skin care agents. Powders such as talc or starches enhance products esthetically, as do alkanolamides and propoxylated alcohols, which provide emolliency to sticks, and silicones, which act as both effective lubricants and anti-whitening agents. Glycerol esters keep metal agents such as aluminum zirconium stable in stick formats.
Some of the companies supplying inactive materials to antiperspirant and deodorant manufacturers are Dow Corning, ICI Specialty Chemicals, and Witco.
