Emulsifiers over time: from basic solutions to high-tech ingredients

The first evidence of personal care in Europe and North Africa dates back to ancient Egypt. Cleopatra is said to have bathed in milk and honey to smooth and moisturize her skin. In medieval times, people in Europe used donkey milk for bathing and washing, and applied ordinary butter to the skin giving a pleasant feel to the skin to give it a pleasant feel.

The beginning of modern skin care in the 1910s and 20s

The first commercial stable water-in-oil emulsion was Nivea cream, launched by Beiersdorf around 1910. The formulators used lanoline as an emulsifier (known as Eucerit^®), which had originally been developed for medical use.
The first oil-in-water emulsifiers appeared around 1920: formulators mainly used fatty acid salts, like stearic acids, neutralized with potassium hydroxide.
In the late 1920s formulators started to use a combination of glyeryl stearates and potassium stearate, nowadays known as Glyceryl Stearate SE like Cutina^® GMS-SE which makes it easy to produce a broad range of cosmetic emulsions.

Differentiating the portfolio in the 1930s

In the 1930s, manufacturers used various alkalis for saponification like potassium carbonate or triethanolamine to alter the properties of the emulsifiers. But concerns rose about the high pH value of the emulsions. This also led to the emergence of a new emulsifier structure: sodium alkyl sulfates for example in the Lanette^® range. They can be used at a broader pH range than stearates (pH 5.5 to 8.5) and offer good self-emulsifying properties when combined with fatty alcohols. However, their skin compatibility for sensitive skin is not considered as optimal.

Gaining momentum after World War II

After World War II, research and development activities for new emulsifiers quickly picked up speed again. Fatty alcohol polyglycolester and fatty acid polyglycolester-based products appeared on the market, and companies enhanced their existing portfolios of well-established emulsifiers.

More emulsifier options in mid-20th century

Around 1950, the first ethoxylated sorbitan esters and ethoxylated fatty alcohols for use in personal care products were launched, a real milestone in the industry. With a broader pH flexibility, a higher tolerance to salts and their usage in phase-inversion-temperature (P.I.T.) emulsions, ethoxylates like Cognis' Eumulgin® types, have become important emulsifier structures, reaching their peak in the 1980s.

The 1970s and 1980s saw the development of water-in-oil emulsifiers including PEG derivates and glycerol and polyglycerol esters. Two examples are PEG-7 Hydrogenated Castor Oil (Dehymuls^® HRE 7) and Polyglyceryl-3 Diisostearate (Lameform^® TGI), both of which are cold-processable, allow formulators to use high amounts of water and achieve a broad range of textures. The emulsion stability, however, also depends on the polarity of the emollient, as shown in table 1 and 2. 

Sustainability as an important market driver since the 1990s

In the 1990s researchers focused on developing water-in-oil emulsifiers that could be used no matter what the polarity of the oil phase is. Furthermore, health and sustainability-related issues affected the emulsifier market: vegetable-based ingredients became more popular and led to an increased demand for non-petrochemical emulsifiers. One example of a new type of water-in-oil emulsifier that fulfills all of these demands is Polyglyceryl-2 Dipolyhydroxystearate (Dehymuls^® PGPH by Cognis). It offers excellent skin compatibility, is EO-free and based on vegetable sources and can be used cold and hot processes irrespective of the polarity of the emollient, for a wide range of textures (see table 3). 

The sustainability trend also influenced the oil-in-water emulsifier portfolio: researchers on a quest for non-ionic emulsifiers based on natural, renewable raw materials had the idea to bring alkyl polyglucosides (APG^® by Cognis) into play. One of the first oil-in-water emulsifiers that combined alkyl polyglucosides and fatty alcohol was Cetearyl Glucoside (and) Cetearyl Alcohol – sold as Emulgade^® PL 68/50 by Cognis. The self-emulsifying cream base is 100% vegetable-derived, EO-free and very mild.

21st century demand for multi-benefit emulsifiers

The current century has seen an increased demand for cost-effective, sophisticated formulations that offer multiple consumer benefits. Anionic emulsifiers with polyvalent ionic groups can fulfill many needs. Sodium Stearoyl Glutamate (Eumulgin^® SG by Cognis) and Disodium Cetearyl Sulfosuccinate (Eumulgin^® Prisma by Cognis), for example, are two oil-in-water emulsifiers that stabilize emulsions efficiently at a dosage of 0.25% or above. Both ingredients are highly compatible with electrolytes, including water-soluble UV filters. They also support lamellar structures, which results in increased emulsion stability. Based on natural, renewable raw materials, Sodium Stearoyl Glutamate allows manufacturers to formulate in line with BDIH and Ecocert standards. Disodium Cetearyl Sulfosuccinate provides very good skin compatibility and high flexibility in formulations, therefore being ideal for sophisticated formulations providing multiple benefits.



Disodium Cetearyl Sulfosuccinate (Eumulgin^® Prisma by Cognis) provides excellent emulsion stability thanks to its ability to support lamellar structures.