Wise Words from the Bench with Jean-Jaques Étienne, PhD

By: Katie Anderson (Schaefer), Cosmetics & Toiletries magazine

Posted: March 26, 2012, from the May 2012 issue of Cosmetics & Toiletries.

Jean-Jaques Étienne, PhD

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• Biography for Jean-Jaques Étienne, PhD

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C&T: What do you find most difficult about product development?
Creating complementary products to a fragrance line can be difficult because they must smell the same. A fragrance composition in alcohol produces something beautiful but the same fragrance in a [product] like a shampoo can disappear completely. [In addition, there are] scents associated with cosmetic ingredients; in bath oils and gels, lauryl ether sulfate has a specific smell that is difficult to cover. [Further], a fragrance compound might be soluble in alcohol but is insoluble in the water phase of an emulsion. Quantities can also affect the way different products smell; in the alcohol, the fragrance compound can be 12–13% but in the cosmetic products it is difficult to go over 3–4%. Of course, these products must also stay within a specific cost range.

C&T: How can the formulator overcome these challenges?
The formulator should create complimentary cosmetic products that are as discreet as possible with no specific smell. Then they should look closely at the behavior of the fragrance with the perfumer. For example, vanilla is widely accepted so perfumers use it frequently, but vanilla browns emulsions.

C&T: How can a formulator work better with a perfumer?
[Since] cosmetic ingredients introduce their own specific smell, the formulator should always choose ingredients that do not smell or smell the least. The cosmetic side often says that masking the odor is the perfumer’s responsibility but this a foolish position. Perfumers are not always able to cover such fragrances and sometimes they succeed in the beginning, only for the odor to reappear with time. Even an odor viewed as acceptable on the cosmetic side is a problem for a perfumer.

C&T: What technology has revolutionized the cosmetic industry?
In my time in cosmetics, I have seen the concept of skin hydration become recognized due to the invention of the rheometer. The idea was to measure the resistance of skin to show that a hydrating cream increases its conductivity. A change in the resistance of the skin showed that the water level in the skin was improved. This may have been the first example of instrumentation in cosmetics being developed to demonstrate a claim. Many instruments have since been developed to demonstrate the effectiveness of cosmetic claims. Another example is confocal microscopy, which [makes it possible] to look inside the skin to explain the actions that occur there. These instruments helped communicate the mechanisms of action behind cosmetics, which can be difficult.

C&T: What do you see in the future for cosmetics?
In 2003, I had the initial idea of a process now under development that inhibits the penetration of fragrance allergens. In fragrance, there are a lot of regulations on allergens but if we were able to inhibit the penetration of such substances with a film, these allergens, such as aldehydes, would not be a problem. [Therefore, a film is currently being developed] that is soluble in alcohol and does not smell bad but the details are still confidential. This technology would greatly benefit cosmetics [in that formulators could manage which] substances stay on the skin and which ones penetrate. The film would act like a net, retaining undesirable substances such as parabens but allowing actives to penetrate and act on the keratinocytes. Parabens are there to preserve [creams and other products in their packages to avoid microbial growth], not to penetrate the skin for cosmetic activity. This would eliminate many problems in the cosmetics industry.