An alternative surfactant for hair care products.

FOR DECADES, typical shampoos have contained sodium lauryl sulfate (SLS), its ethoxylated version sodium laureth sulfate (SLES) for clear shampoos or ammonium lauryl sulfate for acid shampoos. They have superior foaming properties, but can be eye irritants. Since they are derived from coconut oil, they could be considered "naturally derived." Fatty alkanol amides boost the foaming ability and viscosity of a shampoo.

Cocamido betaines also improve shampoo foam. Sodium chloride can be added to increase the viscosity of a lauryl sulfate shampoo after it reaches room temperature.

Sodium laureth sulfate is less irritating than sodium lauryl sulfate, probably because of the dilution effect of ethylene oxide. Suppliers strive to create a mild surfactant that foams as well as the lauryl sulfates. Secondary surfactants such as betaines, disodium laureth sulfosuccinate and sodium lauroamphoacetate are much milder to both skin and eyes than the lauryl sulfates.

Stepan Company is offering a naturally-derived secondary surfactant called Stepan-Mild L3 (INCI: Lauryl lactyl lactate), which is a reaction product of lauryl alcohol and lactic acid. Its configuration is:

[FORMULA NOT REPRODUCIBLE IN ASCII]

This is a clear, colorless, thin liquid (100% active) that freezes at -16.7[degrees]C. It acts as a viscosity builder, foam booster and stabilizer, emulsifier, emollient and solubilizer for actives such as salicylic acid and triclosan. It also provides moisturization and softness to skin. It can be used in all cleansing products, creams and lotions, makeup, hair conditioners, and solid anhydrous antiperspirants.

It reduces the critical micelle concentration (CMC) of primary surfactants and lowers surface tension. In one test, Stepan combined the material with SLS and SLES and found it was more efficient in lowering the CMC than the SLS and SLES with either cocamide MEA or cocamidopropyl betaine. Tests were run using the same chemical combinations already mentioned that showed Stepan-Mild L3 mixture lowered the interface saturation time faster. This property may improve product flash foam. Other tests proved it builds higher viscosity with less salt than other secondary surfactants at the same ratio and total actives level. Secondary surfactants used with SLES were cocamidopropyl betaine, sodium lauroamphoacetate, cocamide MEA and disodium laureth sulfosuccinate. Tests showed that the L3 was as mild as all three chemicals.

The suggested use concentration is 1-3% in cleansing products and 1-15% in treatment products, creams and lotions.

Here are a couple of formulation ideas to consider:

Clear Body Wash

Ingredient                       % Wt.

Water                         q.s. to 100
Sodium laureth sulfate               14.0
Stepan-Mild L3                        1.0
Silicone Quaternium-20                1.0
Glycerine                             0.8
Perfume, dye, preservative           q.s.
Sodium chloride                      q.s.
Sodium hydroxide (50% sol.)          q.s.
Citric acid (50% sol.)               q.s.

The last two ingredients adjust pH,
but no pH is suggested.

Skin Lotion

Ingredient                       %Wt.

Water                         q.s. to 100
Steareth-20                           1.0
Stepan-Mild L3                        3.0
Isopropyl palmitate                  10.0
Cetyl alcohol                         3.0
Glyceryl stearate                     2.0
Preservative, color                  q.s.
Sodium hydroxide (50%)               q.s.
Citric acid                          q.s.

HARVEY FISHMAN HAS A CONSULTING FIRM AT 34 CHICASAW DRIVE OAKLAND, NJ 07436, [e-mail], SPECIALIZING IN COSMETIC FORMULATIONS AND NEW PRODUCT IDEAS, OFFERING TESTED FINISHED PRODUCTS. HE HAS MORE THAN 30 YEARS OF EXPERIENCE AND HAS BEEN DIRECTOR OF RESEARCH AT BONAT, NESTLE LEMUR AND TURNER HALL. HE WELCOMES DESCRIPTIVE LITERATURE FROM SUPPLIERS AND BENCH CHEMISTS AND OTHERS IN THE FIELD.