Selecting Rheology Modifiers to Meet Clean Beauty Trends in Skincare

TAGS:  Natural/ Organic    Skin Care    

This is a sponsored article by Elementis.

What does Clean Beauty in Skincare mean?

Increasingly stringent regulation of cosmetic products has generated awareness amongst consumers regarding ingredients that may be detrimental to their health. This awareness has further fueled the rise of clean beauty products. Today’s consumers are showing preference for products that contain only clean and safe ingredients. For skincare products, clean beauty means that consumers can trust what goes on their face and body. The product should enhance the appearance and texture of their skin without any side-effects in both the short-term and the long-term. In addition, the ingredients should be sustainable and recyclable with minimal environmental impact. With an estimated growth from $5.4 billion in 2020 to $11.6 billion by 2027, the clean beauty market has an expected CAGR of 12.07% per year.

As the lists of desirable and undesirable ingredients get longer, consumers must rely on regulatory compliance statements, and third-party certifications to ensure that the ingredients in their cosmetics are organic and produced with the best sustainability practices.

The COSMOS-standard signature is a consumer guarantee for organic and natural cosmetics which emphasizes the following:

• Environmentally friendly production
• The concept of green chemicals
• Responsible use of natural resources
• Absence of petrochemical ingredients
• Absence of GMO

Other emerging trends are also tied into Clean Beauty. For example, in 2019, the WHO declared air pollution as the biggest environmental health risk to humans. Exposure to air pollution can cause skin dryness, clogged pores, uneven skin tone and leads to pre-mature aging. To counter the effects of air pollution, consumers are turning to more frequent use of both mild and deep cleansing products as well as moisturizers. And, consumers want these skincare products to be clean, and more and more even vegan. Vegan cosmetics avoid use of animal by-products and employ alternatives to animal experimentation for product development and testing.

The hottest topic in clean beauty skin care products today is microplastic-free formulations. Microplastics are solid plastic particles barely visible to the naked eye. These non-biodegradable fragments are composed of mixtures of polymers and functional additives. Microplastics are widely used in cosmetics as exfoliating agents and as rheology modifiers (thickeners). To significantly reduce the amount of microplastics that enter the environment, regulators in Europe are in the process of restricting the use of intentionally added microplastic particles to consumer products. Therefore, cosmetics formulators are re-evaluating their microplastic-free choices in the rheology modifiers they are incorporating into their skin care formulations.

Four Types of Rheology Modifiers in Skin Care Formulation

Rheology modifiers, commonly referred to as thickeners, regulate and stabilize the viscosity of the aqueous phase. They are incorporated in formulations to provide suspension control, reduce phase separation, and prevent syneresis. Rheology modifiers help enhance the texture and feel of skin care products. They affect how the product appears in a bottle, how easy it is to pour or scoop, how it rubs into the skin, and how easy it is to rinse and remove.

Skin care cosmetics are generally based on one of the following types of rheology modifiers:

Microplastics (Synthetic Polymers)

Polyacrylates or carbomers are synthetic polymers (microplastics) that have been used in cosmetic formulations since the 1960s. During the last few years, concern around the impact of microplastics on the environment and human health has increased significantly. Since most personal care products are designed to be flushed down the drain after use, microplastics end up in the environment. Estimates show that around 130 tons of microplastics enter the wastewater treatment systems annually from cosmetics. Particles that are not removed during sewage treatment enter the aquatic environment and travel up the food chain through plankton, worms and fish to mammals. Microplastics penetrate into cells and tissues causing adverse effects on immune cells and organs. In 2018, use of plastic microbeads in cosmetics and personal care products was banned in many countries including Germany. In 2020, the European Chemicals Agency (ECHA) proposed banning use of microplastics in several consumer products including cosmetics.

Starch

The earliest use of starch is cosmetics dates back to the Romans. Today, corn, rice, potato and tapioca starch are used in skincare formulations as natural ingredients to improve rheology and application properties. COSMOS approved grades are available for cosmetics use that provide an attractive alternative to microplastics. Natural starches, however, show poor heat resistance and may lose viscosity at elevated temperatures. Furthermore, starch is insoluble in cold water and requires heating for incorporation into the formula.

Xanthan Gum

Xanthan gums are polysaccharides derived from the fermentation of carbohydrates. In commercial production since the 1960’s, they are used in a variety of cosmetics and personal care products including color cosmetics, skin care and hair care products. Xanthan gums readily dissolve in water to produce highly viscous solutions at low concentrations. Formulations based on Xanthan gums, however, leave a tacky feel on the skin which is undesirable in many skincare applications.

Natural and Synthetic Clays

Clays are fine-grained rock or soil materials that are primarily composed of hydrates of aluminum silicate. In personal care products, use of clays dates back to more than 2,000 years. They are added to formulas for thickening, suspending, stabilizing emulsions, and absorbing oils. The most common clays used for thickening water-based products are hectorite clays. Hectorite is a smectite clay mineral that swells after immersion and dispersion in water. Under the right conditions, it imparts shear-thinning flow and thixotropy with efficient sedimentation control.

Hectorite Clay is a Preferred Natural Rheology Modifier (Thickener)

Elementis offers a range of rheological additives for aqueous cosmetics and toiletries. BENTONE HYDROCLAY™ 2000 and 2100 are highly beneficiated, readily dispersible powdered smectite clays used to impart thixotropic viscosity and excellent suspension control to the water phase of cosmetics. The company has offered Hectorite clays, and their expertise in formulating with them, since the 1930s, as Elementis owns the purest and largest hectorite clay mine in the world.

In skin care cosmetics, BENTONE HYDROCLAY™ 2100 offers a viable alternative to polyacrylates or carbomers across a wide range of products. It can be used to achieve a host of desirable properties in skin care applications. As a fully natural, vegan, COSMOS approved rheology modifier, BENTONE HYDROCLAY™ 2100 fits the needs of today’s consumers who demand clean and safe beauty products with minimal environmental impact. BENTONE HYDROCLAY™ 2100 is a superior alternative to starch which exhibits poor heat resistance and may lose viscosity at elevated temperatures. BENTONE HYDROCLAY™ 2100 produces a non-tacky and softer skin feel.

BENTONE HYDROCLAY™ produces a smooth, silky feel while significantly improving the cleansing efficacy of mild surfactant systems. It offers a mattifying effect with moisture retention properties giving a flawless look to the skin. BENTONE HYDROCLAY™ stabilizes viscosity at varying temperatures under shear conditions. It is cold processable, imparts thermostable thixotropy/pseudoplasticity and reduces phase separation & syneresis. BENTONE HYDROCLAY™ is suitable for a wide range of applications. It is recommended for use in skincare creams, lotions, facial make-up, sun care products, color cosmetics, hair care products as well as deodorants.

Explore Complete Range of BENTONE HYDROCLAY™ from Elementis »

The key performance benefits of BENTONE HYDROCLAY™ 2100 for Skincare are summarized below:

• Creates flawless looking skin
• Leaves a light and luxurious skin feel
• Produces a mattifying, soft-focus effect
• Enhances moisture retention

• Improves cleansing efficacy

• Provides formulation versatility
• Cold processability prevents degradation of sensitive ingredients
• Synergistic with other thickeners
• Suitable for a wide range of products and applications

• Provides stability of suspension to low viscosity formulas
• Heat stability
• Reduced syneresis

Comparison of BENTONE HYDROCLAY™ 2100 Performance with Other Clays and Gums

Comparative studies show that BENTONE HYDROCLAY™ 2100 offers significant advantages over other clays and gums when used in cosmetic formulations including:

• Superior cleansing ability
• Higher oil absorption
• Non-tacky and softer skin feel

Superior Cleansing Ability of BENTONE HYDROCLAY™

BENTONE HYDROCLAY™ 2100 has superior cleansing ability as compared to other natural and synthetic clays. In a wash experiment, simple cleansing creams were formulated with 3% BENTONE HYDROCLAY™ 2100 and 3% of competing clay materials. A blend of artificial sebum and black pigment was applied to the forearm, as shown in Figure 1. The black marks were washed under a running tap with the help of the three cleansing creams. The residual mark on the skin was visualized using VisioFace® RD (Courage & Khazaka). The visuals show that BENTONE HYDROCLAY™ 2100 exhibits outstanding cleansing efficiency compared to synthetic sodium magnesium silicate and magnesium aluminum silicate -based cleansing creams.


Fig 1 (a) depicts: Equal amounts of artificial sebum with black pigment was applied to the forearm. Clay cleansing cream with 3% of different clays applied on top ad washed

Figure 1: BENTONE HYDROCLAY™ 2100 exhibits superior cleansing ability when compared to other natural and synthetic clays.


Figure 2: BENTONE HYDROCLAY™ 2100 has superior oil absorption properties

Excellent Suspension of Actives, Powders and Pigments with BENTONE HYDROCLAY™

The unique structure of BENTONE HYDROCLAY™ 2100 allows actives, powders, and pigments to be evenly suspended within the clay network. The uniform distribution of key ingredients such as sun filters and exfoliators results in an even application on the skin.

Non-tacky, Softer Skin Feel with BENTONE HYDROCLAY™ in Comparison to Gums and Cellulose

Consumers expect skin formulations to leave their skin soft, smooth and without tackiness. Use of gums and cellulose thickeners in skin formulations can leave a tacky feel. Figure 4 shows that BENTONE HYDROCLAY™ 2100 produces a non-tacky, soft skin feel as compared to Hydroxyethylcellulose, Xanthan gum and Guar Gum.


BENTONE HYDROCLAY™ 2100 produces a soft non-tacky feel in skin formulations

Example Skincare Formulations Incorporating BENTONE HYDROCLAY™

The following sample formulations demonstrate how BENTONE HYDROCLAY™ 2100 can be incorporated into cosmetic recipes to enhance the feel, cleansing ability, and oil-absorption properties of the formula while improving product stability.

Poppy Seed Exfoliating Balm

This fluffy cloud like balm gently exfoliates and cleanses the skin. Incorporation of BENTONE HYDROCLAY™ 2100 into the formula provides the following benefits:

• Excellent suspension of poppy seeds
• Fluffy cloud-like texture
• Improved cleansing properties
• Compatibility with non-ionic surfactants

Phase	Ingredient	Supplier	%w/w
A	Deionized Water		68.00
B	Glycerin		6.00
	BENTONE HYDROCLAY™ 2100	Elementis	2.00
C	Decyl Glucoside	BASF	10.00
	Glyceryl Stearate	Evonik	3.00
D	Dehydroacetic Acid (and) Benzyl Alcohol	Lonza	1.00
E	Papaver Somniferum (Poppy) Seeds		10.00

Formulation for Poppy Seed Exfoliating Balm Incorporated with Elementis' BENTONE HYDROCLAY™ 2100



BENTONE HYDROCLAY™ 2100 with excellent suspension of poppy seeds for improved cleansing properties

Face Illumination Serum

This natural, oil free serum provides the perfect base for your make-up routine as it offers a healthy-looking glow without being sticky. Incorporation of BENTONE HYDROCLAY™ 2100 into the formula provides the following benefits:

• Imparts texture
• Improves Stability
• Facilitates even and smooth application

Phase	Ingredient	Supplier	%w/w
A	Deionized Water		93.20
	CI 16035 (SunCroma C37-A207, FD&C Red No. 40, 1% Solution in water)	Sun Chemical	0.10
B	BENTONE HYDROCLAY™ 2100	Elementis	3.00
	Xanthan Gum	CP Kelko/Rahr	0.20
C	Dehydroacetic Acid (and) Benzyl Alcohol	Lonza	1.00
D	SunPuro Iridescent Red (Mica and Titanium Dioxide)	Sun Chemical	2.50
E	Citric Acid (10% Solution in Water)		q.s.

Formulation for Face Illumination Serum Incorporated with Elementis' BENTONE HYDROCLAY™ 2100

Conclusion

Consumer demand for clean beauty products necessitates use of natural and sustainable ingredients. Microplastics have long been used in cosmetic formulations as rheology modifiers. Recent regulatory changes require cosmetic formulators to move away from the use of microplastics. BENTONE HYDROCLAY™ 2100 from Elementis is a COSMOS approved, natural and sustainable ingredient that provides stability of formulation. It also offers additional benefits such as superior cleansing ability, enhanced oil absorption, excellent suspension of actives, and a non-tacky, mattifying look and feel.

ELEMENTIS' BENTONE HYDROCLAY™ Product Range