Cosmetic Formulation Basics - Skin Lotion

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Since skin care represents the largest market in cosmetics and oil soluble ingredients are often the best performing skin materials, it’s helpful to learn to make emulsions.  We can’t teach you that in this short post, but we can give you the basics behind skin lotions.

How a skin lotions work

A skin lotion is a pseudo-stable mixture of oils and water.  The oils are used to provide moisturization to skin.  This can happen in a variety of ways including changing the feel, attracting water to the skin, and blocking water from escaping the skin.  When put on the skin, lotions interact with skin proteins and immediately soothe dry feeling hands.  Over time, the occlusive agents in the lotion prevent water from leaving the skin which helps build moisture in the surface.  This additional moisture ultimately mitigates the problems associated with dry skin.

Skin lotion ingredients

The primary ingredient that make lotion include both water soluble ingredients and oil soluble ingredients.  To hold them together requires an emulsification system.

Moisturizing ingredients

The most common moisturizing ingredients are occlusive agents which create a barrier that blocks water from escaping the skin.  Ingredients like Petrolatum, Mineral Oil and Dimethicone can all be used as occlusive agents.  Humectants, which are ingredients that attract water, are also added to lotions.  Glycerin is the most commonly used humectant.  Finally, emollients are added to improve the feel of the lotion on the skin.  They can reduce the tackiness and greasiness caused by the other moisturizing ingredients.  Common emollients include coconut oil, cetyl esters, and certain silicones.

Other ingredients

In addition to the moisturizers, skin lotions must also contain emulsifiers that can help combine the oil materials with the water.  Glyceryl Stearate and Stearic Acid are commonly used.  Other ingredients such as thickeners help keep the formula stable and make it more appealing to use.  Raw materials such as fragrance, preservative, and colorants are also included to make a well-rounded formulation.

Here is a typical lotion formula.

Click on image to enlarge it.