More moisture. Skin craves it and suppliers are delivering it. One of them, CP Kelco, Atlanta, GA, offers two moisturizing ingredients under the name of AquaMax. The INCI name for AquaMax HM is sodium glutamate or natto gum; for AquaMax LM, it is potassium hydrolyzed polygamma-glutamate or natto gum. The company prefers the natto gum designation.
Both are based on polyglutamic acid (PGA), a naturally occurring amino acid polymer originally found in an Asian fermented soybean product called natto. PGA has been used in industries such as personal care, food, nutritional supplements, pharmaceutical and agriculture. They are manufactured under controlled fermentation conditions using a Bacillus subtilis strain.
The two products differ in molecular weight (HM has the higher weight). Tests were run showing that the HM is highly effective in capturing and retaining moisture. It has a synergistic function with other moisturizers such as hyaluronic acid (HA). Compared to HA, the HM captured 2.4-4 times more moisture over a 48-hour period and retained this moisture.
The stated benefits of AquaMax are:
- Effectively captures and retains moisture;
- Helps enhance and extend hyaluronic acid functionalities;
- Increases the level of natural moisturizing factors;
- Contributes to maintaining and improving the structural integrity of the skin;
- Enhances skin moisture, elasticity, and reduces transepidermal water loss; and
- May moderate undesirable immune responses in the skin.
AquaMax extends the life of hyaluronic acid in the skin by inhibiting the action of the hyaluronidase, a collection of enzymes that hydrolyze hyaluronic acid (HA) for first reference. Tests indicated that a 97% inhibition of hyaluronidase was achieved with the use of AquaMax at a concentration of 0.008%. Also, AquaMax enhanced the stability of HA in the presence of hyaluronidase by protecting 92% of the HA with a concentration of only 0.004%. It is theorized that the LM, due to its small molecular size, protects the HA in the skin, while the HM protects the HA added externally by the use of moisturizing products.
AquaMax is compatible with many cosmetic ingredients such as thickeners, resins and solvents. However, equal parts used with Carboxy vinyl polymer (2% each) caused a decline in viscosity. It can be readily dissolved with moderate agitation in water to get concentrations of up to 2% for HM or 4% or higher for the LM.
To illustrate its use, CP Kelco provides the following eye gel formula. It is said to be a viscous eye gel that reduces the puffiness of the eyelid and moisturizes to give wrinkle reduction.
Moisturizing Eye Gel
|Acrylates/C10-30 alkyl acrylate crosspolymer||0.9|
|Liquid Germall Plus (Ashland)||0.5|
|Flowerpone Rose (Symrise)||2.0|
Procedure: Add first ingredient to water and heat to 80-85°C. Premix xanthan gum with glycerine to make slurry. Add to batch and mix. Add both AquaMaxes. Mix phase B in separate container and add sodium hydroxide to get a clear gel. Add to Phase A. Cool to 50-55°C and add phase D.
The product is a viscous gel (17000cps) with a pH of 5.0 to 6.0.
Harvey M. Fishman
Harvey Fishman has a consulting firm in Wanaque, NJ, 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, Nestlé LeMur and Turner Hall. He welcomes descriptive literature from suppliers and bench chemists and others in the field.