Formula Anatomy Deciphered: Temporary Hair Depilation

By: Eric S. Abrutyn, TPC2 Advisors Ltd., Inc.

Posted: December 29, 2010, from the January 2011 issue of Cosmetics & Toiletries.

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Farnesoid X receptor forms a heterodimer with the retinoid X receptor (RXR) and binds to an inverted hexa- nucleotide repeat spaced by one nucleotide to promote its target gene. It is activated through interaction with ligands such as farnesoids and bile acids. Co-activators such as DRIP205/TRAP220, SRC-1 and PGC-1 alpha can also enhance the transcriptional activity of farnesoid X receptor by bridging between the ligand-activated farnesoid X receptors and basal transcription machinery, and/or influencing the chromatin structure.

In the disclosed patent, the farnesoid X agonist is preferably a compound from the group of bile acids and/or their analogs or derivatives, and a compound from the group of farnesoids and/or their analogs or derivatives that interact strongly with farnesoid X receptor upon application to skin.⁴

Featured Ingredient: Thioglycolic Acid

Thioglycolic acid and its alkaline salts have been used as depilatory agents for years in the personal care industry. They are classified as thiols, i.e., compounds that contain a sulfur-hydrogen functional bond, and are considered stronger acids. Thiolate-conjugated bases are easily formed and are effective nucleophiles in the bimolecular nucleophilic substitution (S_N2 reactions) of alkyl halides and tosylates. Thioglycolic acid is a simple sulfur, group-chained, carboxylic acid, as shown in Figure 2.

A clear, water-soluble liquid, thioglycolic acid melts at -16°C and boils at 96°C. Its sulfur group is reactive with bases, acids, ketones and organic halogen compounds while its carboxylic acid group is preferentially reactive in the presence of alcohols or amines. The material has been applied in both body hair removal and in hair resetting, e.g. hair straightening and waving. Additionally, thioglycolic acid and its derivatives are also used: to inhibit corrosion in the oil field industry; in the shrink-resistant treatment of wool; in fabric dyeing; in leather processing; and as the starting material for the synthesis of PVC stabilizers.

Finished Depilatory Products

The following formulations provide a cross-sectional sampling of depilatories currently available on the market in various product forms—i.e., cream, spray and mousse. The information presented is taken from publicly available sources and is included for illustrative purposes only. The estimated ingredient ranges are provided as a starting point from which formulators can build their own unique formulas.