How can a lamellar liquid crystal emulsion strengthen the skin barrier?

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formulation naturality & sustainability
  • November 14, 2023
  • 6 minutes of read time

How can a lamellar liquid crystal emulsion strengthen the skin barrier?

Customers today are looking for simple but effective and pleasant textures. In the search for effectiveness and minimalism, the use of active emulsifiers is a great option for formulators: a single ingredient ensures the stability of the product and the benefits for the consumer. But what are these active textures? Are they easy to formulate? How can you recognise them? What benefits do they have for your cosmetic products?

We would like to introduce you to the benefits of a lamellar liquid crystal emulsion for the stability of the formulation and for the skin barrier with a special solution: MONTANOV™.

seppic montanov lamellar liquid crystal emulsions

How do you define a lamellar liquid crystal?

The lamellar liquid crystal emulsion is a type of emulsion that differs from conventional emulsion systems. It is an ordered arrangement of surfactant and oil molecules formed at the oil-water interface. Due to this ordered arrangement, the lamellar liquid crystal structure emulsion shows better application properties than conventional emulsion systems in terms of stability, controlled release and moisture.

At Seppic, we offer MONTANOV™ emulsifiers that promote the formation of lamellar liquid crystals in emulsions. Indeed, some emulsifiers can create lamellar phases by structuring the aqueous phase and arranging themselves in two layers around the oil droplets. They can form a liquid crystalline phase or a gel phase.

lamellar phases structure Figure 1: Structure of the lamellar phases

How do you formulate a lamellar liquid crystal emulsion?

Let's take the case study with our MONTANOV™ series. MONTANOV™ can be added to the heated oil phase (or to the water phase if the oil content is low). 

The oil phase is added to the heated water phase and emulsified with a homogeniser (rotor-stator). Gradually and carefully cool to 50 °C to allow the formation of lamellar liquid crystals. Complete the cooling process with gentle to moderate stirring and add stressful raw materials such as active ingredients, perfume or preservatives at the end of the process.

Discover our formulation video with MONTANOV™ L:

How can you be sure that your emulsion contains lamellar liquid crystals?

Two different types of lamellar liquid crystals can be recognised under the microscope: those around the oil droplets and those in the continuous aqueous phase.

  • The liquid crystals around the oil droplets take the form of several lamellar bilayers. These form a barrier against coalescence1 . These liquid crystals are anisotropic and are therefore visible under an optical microscope with polarised light in the form of Maltese crosses.
  • Liquid crystals also exist in the continuous aqueous phase in the form of lamellar phases2, 3, 4 . These networks are viscoelastic and more or less consistent, which prevents the phenomenon of creaminess. Unlike the liquid crystals that form around the oil droplets, the lamellar phases in the aqueous phase are not visible under the light microscope, but can be identified under the electron microscope or by rheological analyses. In fact, these lamellar phases increase the elasticity of the emulsion.
lamellar phases under microscope Montanov 202 Figure 2: Microscopic observation of the lamellar phases obtained with MONTANOV™ 202

What are the advantages of lamellar liquid crystals in the formulation?

Theoretically, the lamellar liquid crystal structure should offer several advantages over conventional emulsions in cosmetic applications, e.g. improved stability, controlled release and good skin feel.

This has been investigated in various studies with our MONTANOV™ emulsifiers. On MONTANOV™ 202 emulsions were used to conduct extensive stability studies that mimic extreme conditions. The aim was to understand the influence of time, temperature, transport and formulation composition on the formation and stability of lamellar phases and lamellar bilayers. 

Several formulations were prepared to study the effects of the emulsifier (Seppic's and other emulsifiers), the polymers and the composition of the oil phase on these structures. The emulsions were then exposed to different temperatures (up to 45°C) and a special machine that mimics the effects of transport for up to 6 months. A standardised protocol made it possible to assess the presence or absence of microscopically visible lamellar liquid crystals in the different formulations regularly during these 6 months.

As a result, and in contrast to other emulsifiers tested, MONTANOV™  showed a great ability to form stable lamellar liquid crystals over time, temperature and stability.

What are the advantages of lamellar liquid crystal emulsions for the skin barrier?

When investigating lamellar liquid crystal formulations, we discovered that they are structured similarly to the skin. We can speak of a biomimetic texture.

It can be defined as a texture that mimics the inventiveness of the skin and is inspired by the substances or functions that our skin naturally produces. These similarities between the emulsion texture and the skin optimise the penetration of the ingredients into the stratum corneum for better results.

MONTANOV™ emulsions therefore respect the structure of the skin. This is due to their lipid molecules, which insert themselves between the existing lipids of the stratum corneum. The organisation of the skin is therefore not disturbed, but rather reinforced!

stratum corneum organization with Montanov 202 Figure 3: Organisation of lipids in the stratum corneum before and after application of the emulsion with MONTANOV™ 202

The MONTANOV™ range is more than just an emulsifier for the formulation, it also offers desired benefits for the skin:

  • Reinforcement of the skin barrier: MONTANOV™ 202 and MONTANOV™ L were tested in vitro for the reinforcement of the skin barrier. They show a decrease in transepidermal water loss compared to the reference. Therefore strengthen the tested MONTANOV™ tested strengthen the skin barrier function and limit skin dehydration.
  • Humidity: MONTANOV™ 202, MONTANOV™ L and MONTANOV™ 82 were tested in vivo. They showed a better moisturising effect than the reference. The MONTANOV™ range therefore has a direct immediate effect on skin hydration and continues to act as a water reservoir even five hours after application. The increased moisturisation provided by MONTANOV™ is proof of an efficient, strengthened skin barrier.
Montanov 202 moisturizer Figure 4: moisturising effect up to 5 hours after application
  • Restructuring: The analysis of the skin structure with MONTANOV™ 202 showed a decrease in skin roughness after 30 minutes. The reduction of this factor shows that the emulsifier has a significant restructuring effect. MONTANOV™ 202 is a suitable ingredient for visibly smoothing smoothing of the skin structure.
  • Properties to increase the effectiveness of the active ingredient: MONTANOV™ L has been tested as an efficacy booster for two active ingredients.
    • In order to achieve a longer moisturizing effect, MONTANOV™ L was tested in combination with AQUAXYL™ was investigated. The study showed that together they can significantly increase the moisturising effect for up to 48 hours.
Montanov L booster efficacy Figure 5: Moisturising effect of the combination of MONTANOV™ L and AQUAXYL™
  • In combination with SAKADIKIUM™ , MONTANOV™ L enhances the complexion-improving effect on the skin compared to an ethoxylated emulsifier.
Figure 6 Figure 6: Complexion-improving effect of the combination of MONTANOV™ L and SAKADIKIUM™

The structure of lamellar liquid crystal emulsions therefore offers numerous advantages. 

Let our formulations inspire you to create your biomimetic textures!

Here are two natural examples:

Lotion

Jar Balm

TO REMEMBER
  1. A lamellar liquid crystal emulsion is an ordered arrangement of surfactant and oil molecules at the oil-water interface.
  2. Lamellar liquid crystal emulsions can be observed under the microscope as lamellar bilayers around oil droplets (Maltese crosses) and lamellar phases in the aqueous phase
  3. This type of emulsion is more stable over time, temperature and transport and forms biomimetic structures on the skin.

Contact us if you would like more information and/or samples!

Sources

1Tadros ThF., Dimitrova GT, Luckham P., Ftaelman MC. And Loll P. Euro Cosmetics 3, 17 (1995)

2 Barry B.W. "Viscoelastic properties of concentrated emulsifiers. Advance in Colloid and Interface Science", 5, 37-75 (1975)

3 Barry B.W. and Elleston G.M. "Influence of gel networks in controlling consistency of O/W emulsifiers stabilised by mixed emulsifiers", Journal of Texture, 4, 53-81 (1973)

4 Eccleston G.M. "Functions of mixed emulsifiers and emulsifying waxes in dermatological lotions and creams", Colloid Surface A, 123-124, 169-182 (1997)