The Anatomy of a Formula—Antiperspirant Sticks, Soft Solids and Gels

May 1, 2009 | Contact Author | By: Eric S. Abrutyn, TPC2 Advisors Ltd., Inc.
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Title: The Anatomy of a Formula—Antiperspirant Sticks, Soft Solids and Gels
AP/DEOx
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Keywords: AP/DEO

Abstract: Deodorants have been used for more than 5,000 years, with every major civilization having left a record of efforts to mask body odors. Over time, applications have evolved from masking offensive odors with simple perfumed oil, to today’s complex deodorant and antiperspirant (AP) applications.

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Editor’s Note: Cosmetics & Toiletries magazine is pleased to welcome this new quarterly column, “Anatomy of a Formula,” by Eric Abrutyn to its regular lineup. This column dissects current formulas on the market to examine what ingredients are in them and why.

Deodorants have been used for more than 5,000 years, with every major civilization having left a record of efforts to mask body odors. The early Egyptians, for example, recommended application of perfumed oils such as citrus and cinnamon preparations. Over time, applications have evolved from masking offensive odors with simple perfumed oil, to today’s complex deodorant and antiperspirant (AP) applications.

Excerpt Only This is a shortened version or summary of the article you requested. To view the complete article, please log in or create an account. Registration is Free!

 

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Table 1. Ingredient categories comprising typical AP solids

Abrutyn Table 1

The ingredients necessary to produce a consumer-acceptable AP solid with optimized performance can be divided into four categories (see Table 1), the first of which includes AP actives.

Table 2. Ingredients associated with AP claims

Abrutyn Table 2

The last several years have seen relatively few changes in AP solid formulations. The changes that have occurred mainly center around exchanging the AP actives and the percentages used, along with the addition of other ingredients to allow for extended claims beyond wetness control. Some recent claims and associated technologies are shown in Table 2.

Footnote A

aWetness Inhibiting Performance (WIP) is a trademarked term of Eric Abrutyn and TPC2 Advisors Ltd., Inc.

Formula 1. Right Guard Xtreme PowerStripe Deodorant

This classical cyclomethicone/stearyl alcohol/hydrogenated castor oil formula has some minor additions for claims and skin feel.

A.
Aluminium zirconium pentachlorohydrex GLY active ~17.6% w/w
B.
Cyclopentasiloxane volatile carrier 45–55 C
C.
PPG-14 butyl ether wetting/dispersing agent 2.5–7.5
D.
Stearyl alcohol solidification 12–18
Hydrogenated castor oil co-solidification  2.5–7.5
Myristyl myristate skin emollient 1–5
E.
Fragrance (parfum) scent 1–5
Silica dimethyl silylate viscosity enhancer 1–2
Zea mays (corn) starch encapsulant qs
Silica viscosity enhancer < 0.25
Chromium hydroxide green (and) Yellow 5 lake colorant qs

Procedure: Disperse A in B. Add C to AB and homogenize to improve active dispersion and uniform particle size. Heat to 70–75°C. Stay below cyclomethicone flash point. Separately heat D to ~ 80–85°C. Cool to ~ 75°C. Add D to ABC and homogenize to ensure creamy, soft-feeling stick. Cool to ~ 55–60°C. Add E to batch. Cool to pour temperature (~ 50–53°C). During pouring, balance the need to cool rapidly with the need to generate the right crystalline matrix. Time also depends on heat transfer capabilities; in the lab, approx. 1–2 hr to achieve < 30°C; Note: One could add enhancers such as alkyl methyl siloxane waxes to increase the cooling rate

Formula 2. Rexall Ladies’ Invisible Antiperspirant/Deodorant

This classical cyclomethicone/stearyl alcohol/hydrogenated castor oil formula includes some minor additions for claims and skin feel.

Aluminum zirconium tetrachlorohydrex GLY active ~20% w/w
Cyclopentasiloxane volatile carrier 45–55
Stearyl alcohol solidification 10–15
Hydrogenated polydecene carrier and emollient 2.5–5
Mineral oil moisturization 1–2.5
Hydrogenated castor oil co-solidification 2.5–7.5
Cetyl alcohol co-solidification 1–2.5
Aluminum starch octenylsuccinate wetting/dispersing agent 0.5–2
Petrolatum moisturization qs
PEG-100 stearate (and) glyceryl stearate emulsifier and dispersing agent 0.2–1
Silica viscosity enhancer 0.05–0.2
Fragrance (parfum)  scent qs

Formula 3. Old Spice Red Zone Fresh Soft Solid Deodorant

Compared with Formula 2, this formula requires less critical temperature control and a larger temperature window for filling. Thus, it is critical to monitor its pour temperature to ensure proper dispersion and prevent premature settling.

Aluminum zirconium trichlorohydrex GLY active ~19% w/w
Cyclopentasiloxane volatile carrier 45–55
Dimethicone anti-whitening, lubrication 5-10
Tribehenin solidification 5-10
C18-36 acid triglyceride moisturization 1-5
Fragrance (parfum) scent qs

 

Formula 4. Arrid Total Powder Antiperspirant/Deodorant

This formula is similar to Formula 3 except for the use of hydrogenated castor oil as a secondary solidifier, and talc to provide a more powdery formula while possibly reducing the yellow contribution from the penta AP active.

Aluminum zirconium pentachlorohydrex GLY active ~16–19% w/w
Cyclopentasiloxane volatile carrier 45–55
Petrolatum moisturization 5–10
Tribehenin solidification 5–10
Talc de-yellowing of stick, skin aesthetics 0.5–1.5
Hydrogenated castor oil co-solidification 1–5
Silica viscosity enhancer 0.05–0.2
PEG-25 propylene glycol stearate emulsifier, dispersing agent 0.25–1.0
Fragrance (parfum) scent qs

Formula 5. Secret Clinical Strength Antiperspirant/Deodorant

This P&G-patented, non-classical AP solid stick formulation substitutes stearyl alcohol and hydrogenated castor oil with tribehenin and C18-36 acid triglyceride.

Aluminum zirconium trichlorohydrex GLY active ~20% w/w
Cyclopentasiloxane volatile carrier 45–55
Dimethicone anti-whitening, lubrication 5–10
Tribehenin solidification 10–20
Petrolatum moisturization 1–5
Cyclodextrin  odor absorption 1–5
C18-36 acid triglyceride solidification 1–5
PPG-14 butyl ether  wetting/ dispersing agent 1–2
Fragrance (parfum) scent qs

Formula 6. Dry Idea Antiperspirant/Deodorant

This is a classical AP w/o emulsion clear gel.

A.
Aluminum zirconium octachlorohydrex GLY active 16 approx. % w/w
Water (aqua) volatile carrier, hydrous 45–55
Alcohol denat. volatile carrier, hydrous 5–10
Calcium chloride hydrogen bonding enhancer 0.25–0.5
B.
Propylene glycol refractive index adjuster 1–5
C.
Cyclopentasiloxane volatile carrier, anhydrous 5–10
Dimethicone emollient, antiwhitening 2.5–5
Trisiloxane volatile carrier, anhydrous 1-5
PEG/PPG-18/18 dimethicone emulsifier 7.5–10
Fragrance (parfum) scent qs

Procedure: Mix A in an aqueous tank. Separately mix C in a silicone tank. Compare refractive index of A and C, which should be + 0.005 max to assure best clarity. Adjust A with B to achieve the maximum refractive index spread between the two phases. This will require readjustment of the ratios in A. Using high speed turbulent mixing, slowly add AB to C over 20–60 min without any heat. Apply in-line homogenization and transfer material to a holding tank for filling. This increases clarity and viscosity.
Note: One could eliminate alcohol and replace it with water as well as substitute any volatile or semi-volatile carrier for trisiloxane at 1–5% w/w. In addition, another high refractive index glycolic or water-soluble ingredient could substitute for propylene glycol, and another high refractive index emollient such as phenyl trimethicone could be used in place of dimethicone to reduce skin whitening. Magnesium or sodium chloride could replace calcium chloride.

Formula 7. Revlon Signo Active Deodorant

This is a classical AP clear gel except the level of PEG/PPG-18/18 dimethicone is probably reduced and replaced with some PEG/PPG-19/19 dimethicone.

Aluminum zirconium tetrachlorohydrex GLY active 16–19% w/w
Dipropylene glycol volatile carrier, hydrous 7–10
Dimethicone volatile carrier, hydrous 0.5–2.5
Water (aqua)  volatile carrier, anhydrous 5–10
Cyclopentasiloxane refractive index adjuster 45–55
PEG-12 dimethicone copolymer emollient, antiwhitening 0.25–0.5
PEG/PPG-18/18 dimethicone volatile carrier, anhydrous 5–7.5
Glycerin W/O emulsifier 1–5
Fragrance (parfum) scent qs
PEG/PPG-19/19 dimethicone hydrogen bonding enhancer 0.25–1.0

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