Introduction

Emulsion, a non-homogeneous dispersion system consisting of two immiscible liquid phases, is usually formed by the dispersion of small drops of one liquid phase in another liquid phase, emulsion is thermodynamically and kinetically unstable system. Emulsions can be taken internally or used externally. The process of forming an emulsion becomes emulsification, and the excipient that has an emulsifying effect is called an emulsifier, which is an important part of an emulsion in addition to the water and oil phases.

Subtypes of Emulsifiers

There are many types of emulsifiers, which are divided into natural emulsifiers, synthetic emulsifiers, and solid emulsifiers according to their sources and properties.

Natural Emulsifiers

Natural emulsifiers of plant origin: commonly used varieties include gum arabic, western astragalus gum, pectin, agar, sodium alginate, etc.

Natural emulsifiers of animal origin: commonly used hydrophilic varieties include egg yolk, lecithin, gelatin, sodium cholate, etc. Lipophilic varieties include lanolin, cholesterol, etc.

Synthetic Emulsifier

Synthetic emulsifiers can be divided into cationic, anionic, amphoteric, and nonionic varieties, with anionic emulsifiers and nonionic emulsifiers being employed most frequently.

Anionic emulsifiers: such as sodium stearate, stearic acid send ah, calcium stearate and so on.

Nonionic emulsifiers: polyoxyethylene castor oil, polysorbate, poloxamer, etc.

Cationic emulsifiers: these are more poisonous and have antibacterial and antiseptic properties. Its application is not as widespread as the other two kinds.

Solid Emulsifiers

This category is a number of small solubility, extremely fine solid powder. When emulsified, they can form a stable interfacial film between oil and water, preventing the dispersed phase droplets from contacting and merging with each other, and are not affected by electrolytes, so they can be used in conjunction with natural emulsifiers and surfactants. According to the affinity, they can be divided into the following two categories:

O/W emulsifier: a hydrophilic emulsifier that can be wetted by water and is used in the preparation of o/w emulsions, such as magnesium hydroxide, aluminum hydroxide, etc.

W/O emulsifier: a hydrophobic emulsifier, can be wetted by oil and is used in the preparation of w/o emulsions, such as calcium hydroxide, magnesium stearate, etc.

Examples of Emulsifiers

Polysorbates

Polysorbates, such as Polysorbate 80 (Tween 80) and Polysorbate 20 (Tween 20), are widely used non-ionic surfactants in pharmaceutical formulations. They provide excellent solubilization, stabilization, and emulsification properties, making them suitable for a variety of dosage forms, including parenteral formulations, oral emulsions, and topical creams.

Sodium Lauryl Sulfate (SLS)

Sodium lauryl sulfate is an anionic surfactant commonly used in oral liquid and topical formulations. It improves the wetting and dispersing capabilities of active ingredients, aids in emulsion stability, and enhances foaming.

Conclusion

Emulsifiers excipients are key ingredients in pharmaceutical formulations that require stable emulsions. Through their emulsifying properties, they enable optimal drug delivery, enhance bioavailability, and improve patient compliance. Partnering with Protheragen-ING, a reputable supplier, ensures the availability of high-quality excipients and supports the development of stable and efficacious pharmaceutical products. If you have any excipient requirements, please contact us by phone or email, and we will respond within 2-4 working days.