Use Of HPMC In Hair/Skin Cleanser Allows For Reduction Of Surfactant – Study

Adding 1 percent to 2 percent hydroxypropyl methylcellulose to a hair- or skin-cleansing product allows the amount of surfactant normally used to be reduced by 30 to 60 percent without sacrificing acceptable viscosity and lather properties, according to the Dow Chemical Company.

In a paper presented in December at the Society of Cosmetic Chemists' Annual Scientific Meeting and Technology Showcase in New York, Dow Chemical's Edward DiAntonio notes that most hair- and skin-cleansing preparations contain 15 percent to 20 percent surfactant, though only 5 percent to 7 percent surfactant is required for cleansing.

"The additional surfactant is used to build formulation viscosity and generate desirable lather properties," such as flash foaming, volume, creaminess and density, which make the product "aesthetically pleasing to the final user."

However, surfactants "can be harsh to the skin and hair, causing moisturization reduction and even damage," he says.

The Personal Care Products Council acknowledges on its consumer Web site at ¹ www.cosmeticsinfo.org that surfactants such as sodium lauryl sulfate and sodium laureth sulfate "can cause skin irritation in some persons."

DiAntonio, et al., conducted testing using hydroxypropyl methylcellulose (HPMC) supplied by Amerchol Corporation and two surfactants - sodium laureth sulfate and cocamidopropyl betaine - supplied by Cognis.

The investigators found that reducing the surfactant level in a typical body wash formulation from 15 percent to 7.5 percent resulted in significant loss of viscosity, from 4,000 centipoise (cps) to 200 cps.

Foam volume also was "noticeably lower than that of the control formulation due to lower surfactant level," the authors say.

However, incorporating 1 percent HPMC into the low-surfactant system yielded a viscosity of 11,700 cps - "an even higher viscosity than the full-surfactant control formulation."

Similarly, the foaming level of the low-surfactant-high-HPMC product was higher than both the full-surfactant control and the low-surfactant formulation, according to the study.

Other "higher order" benefits of the low-surfactant-high-HPMC formulation include "significantly" elevated perfume headspace and improved perfume deposition.

Headspace and deposition are the two parameters most relevant to perfume performance, which is "one of the most critical properties of personal cleansing products," the researchers say.

The low-surfactant-high-HPMC formulation with only 0.75 percent perfume provided higher headspace and deposition than the full-surfactant system containing 25 percent more perfume, DiAntonio et al. note.

Using HPMC instead of high levels of surfactant, "the formulator is able to provide unique properties such as improved mildness, improved perfume performance, improved color fading performance, better conditioning properties and increased deposition of active ingredients."

The authors observe that reducing the amount of surfactant and/or perfume used in a hair- or skin-cleansing product can balance out the expense of the added HPMC.

In some cases, the cost of formulating with HPMC is actually less, they say.

"Additional data will be presented that demonstrate the ability of low-surfactant-high-HPMC formulations body washes, hair wet combing from shampoos, and to improve skin moisturization from salicylic acid deposition from anti-acne cleansers."

- Ryan Nelson ([email protected])