Difference Between Oil in Water and Water in Oil Emulsion

The key difference between oil in water and water in oil emulsion is that oil in water emulsions have oil droplets suspended in water whereas water in oil emulsions have water droplets suspended in oil. Another main difference between oil in water and water in oil emulsion is that to achieve the stability of water in oil emulsions, it requires two or more emulsifiers, but to achieve the stability of oil in water emulsions, it requires only one emulsifier.

An emulsion is a mixture of two or more substances that are usually immiscible. It is a form of a colloid. The difference between emulsions and other forms of colloids is that the dispersed and continuous phases of the emulsion are essentially liquids. In addition to the above key difference, another important difference between oil in water and water in oil emulsions is that oil in water emulsions are useful in the production of water-based products while water in oil emulsions are useful in the production of oil-based products in the pharmaceutical industry.

CONTENTS

1. Overview and Key Difference
2. What is Oil in Water Emulsion
3. What is Water in Oil Emulsion
4. Side by Side Comparison – Oil in Water vs Water in Oil Emulsion in Tabular Form
5. Summary

What is Oil in Water Emulsion?

Oil in water emulsions are colloidal systems that have oil droplets dispersed throughout the water. Therefore water acts as the continuous phase of this colloid while oil is the dispersed phase. Oil does not mix with water under normal conditions. But with proper mixing and using stabilizing agents, we can obtain oil in water emulsion. The effectiveness of this system enhances with a small size of dispersed oil droplets. It increases the bioavailability of pharmaceutical products, and it also increases the shelf life of food and beverages.

Moreover, the chemical nature of oil in water emulsions makes it very important in the production of water-based pharmaceutical products. Manufacturers use these emulsions for the production of creams and other oily moisturizers. Furthermore, all emulsions require an emulsifier to stabilize the emulsion. Typically, oil in water emulsions requires more than one emulsifier. Some examples of such emulsifiers include Polysorbate, sorbitan laurate, and Cetearyl alcohol.

What is Water in Oil Emulsion?

Water in oil emulsions are colloidal systems having water droplets dispersed throughout the oil. Therefore oil acts as the continuous phase of this colloid while water is the dispersed phase. Oil does not mix with water under normal conditions. But with proper mixing and by using stabilizing agents, we can obtain oil in water emulsion. The effectiveness of this system enhances with a small size of dispersed oil droplets. It increases the bioavailability of pharmaceutical products, and it also increases the shelf life of food and beverages.

Moreover, the chemical nature of water in oil emulsions makes it very important in the production of oil-based pharmaceutical products. Ex: sunscreen and makeup. It has a mild nature, and hence, it has the ability to leave our skin intact. This makes it useful for the treatment of dry and sensitive skins. Unlike oil in water emulsions, these emulsions require only one emulsifier. Ex: Sorbitan stearate, lecithin, lanolin/lanolin alcohols, and glyceryl monooleate.

What is the Difference Between Oil in Water and Water in Oil Emulsion?

Oil in water emulsions are colloidal systems that have oil droplets dispersed throughout the water. Water in oil emulsions are colloidal systems having water droplets dispersed throughout the oil. Similarly, the dispersed phase of water in oil emulsions is water, while the dispersed phase of oil in water emulsions is oil. Furthermore, the continuous phase of water in oil emulsions is oil whereas the continuous phase of oil in water emulsions is water.

To achieve the stability of water in oil emulsions, it requires two or more emulsifiers. However, to achieve the stability of oil in water emulsions, it requires only one emulsifier. And, the common emulsifiers useful in the formation of water in oil emulsions are Polysorbate, sorbitan laurate, and Cetearyl alcohol. Sorbitan stearate, lecithin, lanolin/lanolin alcohols, and glyceryl monooleate are the common emulsifiers useful in the formation of oil in water emulsions. Water in oil emulsions is useful for the production of oil-based products such as creams and other oily moisturizers. Oil in water emulsions is useful in the production of water-based products such as sunscreen and makeup.

Summary – Oil in Water vs Water in Oil Emulsion

Water in oil and oil in water emulsions are important ingredients in the pharmaceutical industry, for the production of different creams and ointments for topical applications. The difference between oil in water and water in oil emulsion is that oil in water emulsions have oil droplets suspended in water whereas water in oil emulsions have water droplets suspended in oil.

Reference:

1. “Emulsion.” Wikipedia, Wikimedia Foundation, 19 May 2018. Available here
2. Shechter, Tal. “3 Differences Between Oil-in-Water & Water-in-Oil Emulsions.” Ultra High Pressure Homogenizers | BEE International. Available here
3. “Emulsions: When Oil and Water Do Mix J. Peter Clark | August 2013, Volume 67, No.8.” What Is Food Science & Technology? – IFT.org. Available here

Image Courtesy:

1.’1438312′ by the3cats (CC0) via pixabay
2.’Simple emulsion’By Adam Rędzikowski – Own work, (CC BY-SA 3.0) via Commons Wikimedia