The usual remedy for bacterial odor is the antiperspirant or the deodorant which work in different ways. The antiperspirant uses metallic salts such as aluminum and zinc as astringents to close the pores of the skin and thus physically block the flow of perspiration. The most popular form of antiperspirant is the stick, which usually contains stearyl alcohol to form the solid. An example of a simple antiperspirant stick from Heterene Chemical is shown above.
Deodorants work differently. They contain anti-microbials, which kill the odor-forming bacteria. A perfume is usually also provided to furnish a pleasant odor. The active ingredient used to be quaternary ammonium chlorides and phenolics such as para-chloro-meta-xylenol. The most common bactericide used now is Triclosan, available from Ciba. It is usually used at 0.3%. Since it has limited water solubility, it has to be solubilized in the formula.
Stearyl alcohol 26.5
Glyceryl stearate (and) 2.5
Isosteareth-2 octanoate 12.0
Aluminum zirconium 22.0
Procedure:Mix constantly. Heat phase A to 75°C. Add next two ingredients. When well dispersed, cool to 55°C and add fragrance.
A Triclosan Replacement
A new substitute for triclosan is being offered by Hallstar, Hackettstown, NJ. It is called Spectrasolv DMDA or N,N Dimethyldecanamide (INCI name: dimethyl capramide). Its structural formula is:
It is a clear liquid with a mild odor, and a specific gravity of 0.879. It is insoluble in water, but miscible with cyclomethicone and propylene glycol. Tests were done showing that it is not an eye or skin irritant, nor is it an allergic contact sensitizer. It is also not a mutagen, teratogen or sensitizer. Its efficacy against various organisms was also studied.
Two suggested formulas are given below.
Anhydrous Deodorant Stick
Propylene glycol 18.1
PPG-3 myristyl ether 46.7
Spectrasolv DMDA 1.0
Sodium stearate 6.0
In an explosion proof vessel, add the first four ingredients and mix while heating to 80°C. While heating, slowly add the sodium stearate to prevent clumping. When batch is clear, begin slow cooling and fill product between 52 and 58°C. It sets at about 50°C.
The finished product is said to be translucent, almost colorless and virtually odorless.
Hydroglycolic Deodorant Stick
Propylene glycol 75
Sodium stearate 6
Spectrasolv DMDA 1
Procedure:Add first two ingredients to tank, mix and start heating to 80°C. Above 70°C, slowly add the stearate. When dissolved, and batch is clear, begin slow cooling with strong mixing and add last ingredient at 70°C. Fill product between 62 and 68°C. It sets at about 60°C.
The finished product is similar in appearance to the anhydrous stick detailed above.