Gelling Agents / Quasi-Emulsifiers

What are Quasi-Emulsifiers?

 

Quasi-emulsifiers or gelling agents can increase the viscosity (viscosity) of products. Unlike true emulsifiers, they do not have amphiphilic (hydrophilic and lipophilic simultaneously) properties. A Gels consists of a solvent (dispersant) and a gel former, which forms the framework. One can imagine a gel as a sponge soaked with liquid. For cosmetic use, however, it is important that a gel is spreadable and easy to apply. Therefore, the bonds of the molecules within the “sponge” should not be too strong so that they can be destroyed by mechanical action, e.g. massaging in.

 

 

WHat are Hydrolgels?

 

The gels most frequently used in cosmetics are hydrogels. They contain water as solvent and a gel former. They are generally clear and transparent and tend to evaporate the water quickly. As they contain water, they should be protected against microbial contamination by means of preservatives. Due to the fast evaporation of the water, hydrogels have a refreshing and cooling effect on the skin. Therefore, they are often used in sun care but also as shower gels, hair gels or face masks.

 

 

What are Hydrodispersion Gels?

 

Hydrodispersion gels were developed to produce emulsifier-free emulsions. Emulsifiers can cause irritations for some users. Hydrodispersion gels can be adapted to the specific skin condition. O/W and also W/O gels can be produced. They are not only suitable for oily skin conditions because larger amounts of lipids can also be incorporated. The lipids can form the outer phase (W/O gels) and care for dry skin.

 

 

What are Oleogels?

 

Like a hydrogel, an oleogel consists of a lipophilic solvent and a gel former. To increase the viscosity of the liquid lipids, consistency agents of the same substance class as the liquid lipid are used (e.g. jojoba oil and cetyl palmitate or sunflower oil and shea/cocoa butter).

 


Cera Bellina

 

 

  • INCI: Polyglyceryl-3-Beeswax
  • Function: Gelling agent for oil gels
  • Dosage: 8% for oil gels, 2,5 % as a consistency enhancer
  • Use: Emulsions, creating oil gels, decorative cosmetics.

 

Cera Bellina is a chemically modified beeswax with a consistency giving and emulsifying property. In self-produced cosmetics it serves as a gel former for oil-based gels and provides stability to creams and emulsions as a co-emulsifier. Preparations with Cera Bellina can be easily spread on the skin and provide a pleasant, velvety skin feeling. Cera Bellina can create stable and smooth gels with oils (preferably vegetable oils) (e.g. make-up remover gel, sun protection gel, facial care gel etc.). Cera Bellina also has the ability to inhibit crystallization in the oil phase and to increase stability by preventing the formation of granules. This can prevent the graininess of natural butters (especially shea butter) in water-free preparations (lip balm, body butter, etc.). Furthermore, Cera Bellina ensures that cosmetic pigments in an oil mixture are uniformly distributed and remain stable. It coats the pigment particles and forms a stable gel network so that they cannot settle. This is particularly helpful in decorative cosmetics (when e.g. micas and shimmer pigments have to be homogeneously processed for lip gloss and lipsticks) and also for sun protection products (which are made with a powdery sun protection filter).

 


Guar Gum

 

 

  • INCI: Cyanopsis Tetragonalba
  • Function: Gelling agent
  • Dosage: 0,5-1 %
  • Use: Stabilizer in emulsions, gelling agent for gels.

 

Guar gum contains mainly long-chain carbohydrates and can bind a lot of water. It is a natural gel former / thickener for cosmetics. Guar gum can be used in combination with xanthan gum to create a gel-like consistency. It is soluble in warm as well as cold water. If the flour is stirred into boiled water, the gel reaches its final consistency within a short time. In cold processing it will thicken even after hours.

 


Hyaluronic Acid

 

 

  • INCI: Hyaluronic Acid
  • Function: Gelling agent, active substance
  • Dosage: >1%
  • Use: Due to its high price it is generally not used as a gelling agent but rather as an active hydrating substance.

 

Hyaluronic acid acts like a water reservoir and preserves the skin’s elasticity. Already in a concentration of 1 % it forms elastic gels with water. Due to its high price, however, it is only used as a moisture-binding active agent in concentrations of 0.1 % and above.

 


Xanthan

 

 

  • INCI: Xanthan Gum
  • Function: Gelling agent
  • Dosage: 0,2-0,5 % in cremes and Lotions, 0,8-1,0 % in shampoos and shower gels, 1,0-1,5 % in Gels
  • Use: Light gelling agent for shampoos, shower gels, emulsions.

 

Xanthan gum is used as a gelling agent and stabilizer for hot and cold stirred emulsions. It also thickens surfactants, which is why it is a popular skin-friendly thickener for shampoos and shower gels. Xanthan plays a very important role in the production of stable surfactant emulsions with a high water content. It is well soluble in cold as well as in warm water. For easy application it is recommended to first dissolve Xanthan in glycerine or alcohol and then add it to the preparation. In this way a clumping of the gelling agent can be prevented.

 

 

 

Sources
Sources: Elsässer, S. (2008). Körperpflegekunde und Kosmetik: Ein Lehrbuch für die PTA-Ausbildung und die Beratung in der Apothekenpraxis (1. Aufl.). Berlin, Germany: Springer-Verlag.