How to Develop a Micellar Cleansing Gel:

Photo: Patrick Hendry / Unsplash

Micellar cleansing gels have become an indispensable part of cosmetic lines due to their gentle yet effective properties. However, their development requires careful selection of raw materials, optimization of ratios, and compliance with legislative requirements such as REACH and CLP regulations. This practical guide will take you through the entire process—from basic formulation through stability testing to final pH and consistency adjustments. We will focus on key parameters that influence product performance and common mistakes that can be avoided.

1. Defining Requirements and Selecting Suitable Raw Materials

The development of a micellar cleansing gel begins with a clear definition of the requirements for the final product. Consider the target group (e.g., sensitive skin, oily skin, baby care) and desired properties such as pH, viscosity, cleansing efficacy, or dermatological testing. Micellar gels typically work with a pH in the range of 5.0–6.5 to respect the skin’s natural protective barrier. For sensitive skin, choose a lower pH closer to 5.0, while a pH around 5.5 is suitable for universal use.

The foundation of a micellar gel is surfactants, which form micelles—spherical structures capable of capturing impurities and grease. Use mild non-ionic surfactants (e.g., PEG derivatives of fatty alcohols) or amphoteric surfactants (e.g., cocamidopropyl betaine) to minimize irritation. To enhance hydration and gel stability, add polyols (glycerin, propylene glycol) at a concentration of 3–10%. It is also important to select a preservative system compatible with micellar technology, such as mixtures of phenoxyethanol with sorbic acid or parabens, in accordance with REACH regulations and the EU Cosmetics Regulation.

2. Optimizing the surfactant ratio and forming the micellar structure

The efficacy of a micellar gel depends on the correct surfactant ratio and their ability to form stable micelles. Start with a surfactant concentration in the range of 5–15% (w/w), with non-ionic surfactants making up 60–80% of the total surfactant content. Add amphoteric surfactants, such as cocamidopropyl betaine, at 2–5% to improve foaming and mildness. To achieve optimal micelle size (typically 5–50 nm), gradual mixing at a controlled temperature of 40–50 °C is key.

Verify the micellar structure using standard test methods, such as dynamic light scattering (DLS) or microscopic techniques. It is also important to test the cleaning efficiency on model soils (e.g., a mixture of mineral oil and pigments) according to applicable standards. If the gel exhibits low efficiency, increase the proportion of nonionic surfactants or add solubilizers, such as ethoxylated fatty alcohols. Maintain viscosity within the range of 1,000–5,000 mPa·s for easy application and even distribution on the skin.

Photo: Ricardo Gomez Angel / Unsplash

3. Stabilization and texture adjustment of the gel

The stability of micellar gel is crucial for its shelf life and consistent performance. To improve stability, add thickeners such as carbomers, xanthan gum, or cellulose derivatives at a concentration of 0.1–1.0%. These substances not only increase viscosity but also prevent sedimentation or phase separation. To achieve the desired texture, it is advisable to combine multiple thickeners—for example, a carbomer for a creamy consistency and xanthan gum for better spreadability.

Adjust the pH of the gel using buffering systems, such as a mixture of citric acid and sodium citrate, to maintain it within the range of 5.0–6.5. Allow the gel to rest for 24 hours before final pH adjustment to stabilize all components. To enhance sensory properties, you can add small amounts of silicone derivatives (e.g., dimethicone) or light esters, which impart a silky feel to the skin. Be sure to verify stability at various temperatures (4 °C, 25 °C, 40 °C) for at least 4 weeks.

4. Testing and Finalizing the Formulation

Before launching the micellar gel on the market, it is essential to conduct comprehensive testing, including both laboratory analyses and user studies. In the laboratory, verify microbiological stability according to applicable standards, including challenge tests with common contaminants such as the bacteria *Pseudomonas aeruginosa* or the yeast *Candida albicans*. Additionally, perform dermatological tests on volunteers, especially if the gel is intended for sensitive skin or children.

User tests should include an assessment of cleaning efficacy, skin feel after use, and overall satisfaction. Take feedback into account and adjust the formulation if necessary – for example, by reducing the concentration of surfactants if the skin feels tight or increasing moisturizing components for dry skin. Finally, ensure proper product labeling in accordance with CLP/GHS regulations and EU cosmetic legislation, including listing all ingredients in INCI nomenclature and any necessary warnings (e.g., "Do not use around the eyes").

Photo: American Public Power Association / Unsplash

Ensuring compatibility with sensitive skin and minimizing irritation

Micellar cleansing gels are particularly popular for their gentleness, which is why it is crucial to focus on selecting surfactants with low irritation potential. Prefer mild nonionic or amphoteric surfactants, such as cocamidopropyl betaine or alkyl polyglucosides, which effectively remove impurities without disrupting the skin barrier. It is also important to avoid high concentrations of anionic surfactants, such as sodium lauryl sulfate (SLS), which can cause irritation or dryness of the skin. The recommended ratio of nonionic and amphoteric surfactants should constitute at least 70% of the total surfactant content in the formulation.

To further reduce irritation, substances with hydrating and soothing effects can be added, such as panthenol, glycerin, or allantoin. These ingredients help maintain the skin's natural moisture and support its regeneration. It is also important to maintain the pH of the formulation within the range of 5.0–6.0, which corresponds to the skin's natural pH and minimizes the risk of irritation. To adjust the pH, use citric acid or sodium hydroxide, while ensuring careful handling and monitoring pH values throughout the entire mixing process.

Enhancing Cleaning Efficiency and Removing Water-Resistant Impurities

Micellar gels must effectively remove not only common impurities but also water-resistant substances such as makeup or sunscreen. To achieve this, it is advisable to include solubilizers in the formulation, such as PEG-40 hydrogenated castor oil or polysorbate 20, which improve the solubility of oily and waxy components. These substances help micelles better capture and remove impurities without the need for aggressive mechanical friction.

To enhance cleaning performance, a small amount (1–3%) of ethanol or isopropyl alcohol can also be added, which aids in fat dissolution and increases the effectiveness of the micellar structure. However, it is important to ensure that the alcohol concentration is not too high to avoid drying out the skin. Alternatively, natural solvents such as glycerol or propylene glycol can be used, which have a similar effect but are gentler on the skin.

Preservation and Ensuring Microbiological Stability

Micellar gels contain a high proportion of water, making them an ideal environment for microbial growth. Therefore, it is essential to include an effective preservative system in the formulation to ensure the long-term stability of the product. Commonly used preservatives include phenoxyethanol, ethylhexylglycerin, or mixtures of organic acids such as benzoic acid or sorbic acid. These substances effectively prevent the growth of bacteria, moulds, and yeasts without negatively affecting the properties of the product.

When selecting a preservative system, it is important to consider compatibility with other formulation ingredients and to comply with the maximum permitted concentrations according to REACH and CLP regulations. For more sensitive formulations, preservatives based on natural substances, such as grapefruit seed extract or levulinic acid, can be chosen, which are gentler but require more careful stability testing. Microbiological tests according to standard methods must always be performed to ensure the safety of the product throughout its shelf life.

Need help with formulation?

Every cosmetic raw material from GCG Group is supplied with complete documentation, including safety data sheets and technical specifications. Our experts will be happy to advise you on selecting suitable surfactants, additives, or preservative systems for your specific application. Contact us – or browse our catalog of over 1,300 products right away.