OILREE® MY6530 ( Glyceryl stearate se) and OILREE® MY9200 (peg-20 stearate or cetaryl alcohol), as two classic oil in water emulsifiers, is widely used in face cream, lotion, essence, hair conditioner and many other categories, becoming a useful assistant for formulators.
Emulsification stability, in layman's terms, refers to the ability of emulsifiers to maintain a uniform dispersion of oil and water phases during the production, storage, transportation, and use of products, avoiding problems such as delamination, precipitation, oil separation, agglomeration, or peeling. This indicator is not only the core standard for measuring the quality of emulsifiers, but also an important basis for determining their applicability in different formulation systems. MY6530 occupies a place with its excellent self emulsification ability and stable performance in non-polar oil systems, while MY9200 is highly favored for its excellent ingredient compatibility and stability in complex formulations. So, from the perspective of emulsion stability alone, what are the characteristics of these two emulsifiers and how should they be selected according to demand?
I.OILREE® MY6530 emulsion stability
OILREE ® The main active ingredient of MY6530 is glyceryl stearate se, which is a typical self emulsifying
Oil in water emulsifier. Its most significant advantage lies in its self emulsifying properties - it can complete the oil-water emulsification process without relying on other auxiliary emulsifiers, relying solely on its own components. This feature greatly simplifies the development and production process of cosmetic formulas, reduces the difficulty for formulators to adjust multiple
Emulsifier compound ratios, and also reduces the risk of skin irritation caused by the addition of auxiliary emulsifiers.
In terms of emulsification mechanism, the molecular structure of Glyceryl stearate se has both hydrophilic groups and lipophilic groups. When added to the oil-water mixed system, its molecules can be rapidly aligned at the interface between the oil phase and the water phase, forming a layer of interfacial facial mask with certain toughness. This layer boundary facial mask is like a protective shell, which can effectively wrap oil droplets to prevent oil droplets from gathering and merging due to collision, so that the oil phase is evenly and stably dispersed in the water phase, forming a delicate emulsification system.
In terms of oil phase adaptability, MY6530 exhibits excellent stability towards non-polar oil systems. For example, in the basic moisturizing lotion formula with white oil, mineral oil, vaseline and other non-polar oils as the main oil phase, 3% -5% MY6530 can be added to prepare a lotion product with uniform texture and smooth touch. The stability test shows that this kind of lotion can still maintain good uniformity after 6 months of storage at 25 ℃ and 60% -70% relative humidity, without stratification and oil separation. In addition, MY6530 can also maintain good emulsification effect in formulas containing a small amount of medium polarity oils.
However, the emulsifying stability of MY6530 is significantly affected by the polarity of the oil phase. When encountering high unsaturated vegetable essential oils such as rose essential oil and lavender essential oil, or high polar oils such as jojoba oil and almond oil, their ability to form interfacial facial mask will be weakened, and it is difficult to maintain long-term stability by themselves. At this time, it is usually necessary to use a small amount of Emulating wax as an auxiliary emulsifier to enhance the density and toughness of the interfacial facial mask through the synergistic effect of compounding, so as to improve the stability of the entire emulsification system.
In addition to the type of oil phase, environmental factors can also have a certain impact on the emulsification system of MY6530. In a high humidity environment with a relative humidity of over 85%, the water absorption rate of MY6530 material itself will slightly increase, which may lead to a slight decrease in the viscosity of the emulsion system. However, this change will not affect the overall emulsion stability, and the product can still maintain a uniform state. In a low-temperature environment below 0 ℃, the emulsion product may experience a brief turbidity phenomenon, but when the temperature rises to room temperature, the system will quickly restore transparency and uniformity without delamination or agglomeration. This characteristic makes it suitable for storage and transportation in cold regions.
II.OILREE® MY9200 emulsion stability
Unlike MY6530, MY9200 is a composite emulsifier formulated with 30% -40% peg-20 steam and 60% -70% cetaryl alcohol. These two ingredients are scientifically proportioned to form a synergistic mechanism, enabling them to exhibit excellent emulsifying stability in various complex formulation systems.
From the perspective of emulsification principle, peg-20 steam has strong hydrophilicity and can quickly bind with water molecules to form a stable water-based continuous phase in the system, while cetaryl alcohol has good lipophilicity and can be uniformly dispersed in the oil phase, playing a role in refining oil droplets. When the two act together, a dense double-layer interfacial facial mask will be formed at the oil-water interface - the hydrophilic group faces the water phase, and the lipophilic group faces the oil phase. The density and stability of this double-layer membrane is better than that of the single-layer interfacial facial mask formed by MY6530, which can more effectively resist the damage of external factors to the emulsion system.
One of the outstanding advantages of MY9200 is its excellent ingredient compatibility, especially in complex formulations containing high concentrations of electrolytes and functional active ingredients. Electrolytes (such as aluminum chloride in antiperspirant salt, sodium ion in hyaluronic acid, etc.) are generally regarded as the stability killers of emulsification systems, because they are easy to destroy the charge balance of oil-water interface facial mask, resulting in the rupture of interface facial mask, thus causing delamination. However, peg-20 stearate in MY9200 can form a stable chelate structure with electrolyte ions, effectively neutralizing the impact of electrolyte on the interface facial mask, thus maintaining the stability of the emulsion system.
When it comes to pH adaptability, MY9200 is also very awesome. It can adapt to a wide range of pH values, ranging from 3 to 14. It basically covers the pH requirements of all cosmetics formulas. The pH value of the skincare products we usually use is mostly between 4.5 and 7.5. For example, exfoliating products containing AHA may have a pH value as low as 3 to 4, while some alkaline hair care products can have a pH value as low as 8 to 9. Even in an acidic formula with a pH value of 3.5 and 2% fruit acid, the emulsification effect of MY9200 is not easily affected, ensuring that the product maintains a stable state and texture throughout its shelf life.
III. How to choose between two emulsifiers?
Bring MY6530 and ® Looking at the emulsion stability of MY9200, their advantages and applicability are actually very clear. Let's consider how to choose from these aspects:
If it is a simple formula, such as using non-polar oils such as white oil and mineral oil, and adding common moisturizing ingredients such as glycerin and propylene glycol to make basic skincare products, then MY6530 and MY9200 can be used with good emulsification stability. In this case, the advantage of MY6530 is that it is convenient to use without the need for additional emulsifiers, which can reduce costs. The advantage of MY9200 is that it has a longer shelf life, usually 3 to 6 months more stable than MY6530, making it suitable for products that require long-term storage.
But if the formula is more complex, such as containing high concentrations of electrolytes, high polarity oils, or products with particularly acidic or alkaline pH values, then the emulsification stability of MY9200 has an advantage over MY6530. For example, when making hyaluronic acid essence cream containing hyaluronic acid (high concentration electrolyte), high-end face cream containing highly polar vegetable essential oil, or citric acid exfoliating lotion with pH 3.5, MY9200 can be easily held to ensure long-term stability of the product. However, MY6530 has to make additional adjustments to the formula, such as adding oil in water emulsifier to help meet the basic stability requirements. In this way, not only the formula becomes complex, but also the cost may rise.
Let's look at the specific application scenario: if you are making some basic skin care products in small batches, you don't have high requirements on the complexity of the formula and the storage time. For example, you can make your own hand cream, simple moisturizing lotion, body milk, and so on. MY6530 is more cost-effective. Its 25kg bag packaging is suitable for large-scale use.
Overall, OILREE® MY6530 and OILREE® MY9200 is a practical
Water in oil emulsifier, each with its own strengths and applicable scenarios. When a formulator is conducting product development, they can select the most suitable emulsifier based on factors such as formula complexity, active ingredients, storage conditions, and cost budget to create high-quality and stable cosmetics.
Yichang Mingya New Material Technology Co., Ltd.
