Solubilizer – Mist, Sprays, Toners & Bath Oils

When something is soluble it means it is able to be dissolved in water. For example, sugar is soluble in water. When you add sugar to water and stir, it quickly dissolves and you end up with a sweet glass of water.

Solubilizers, as they relate to making cosmetics, help to make otherwise insoluble liquids soluble in water.

For example, if you wanted to make a body spray with essential oils, you could simply add essential oils to your spray, but you would have to vigorously shake your spray before use. 

Enter solubilizers! In the example of the body spray, you would mix your essential oils with a solubilizer before adding to your spray.

This would prevent you from having to shake before each use.

We use solubilizers to solubilize small amounts of oil or oil-soluble ingredients (like essential or fragrance oils) into mostly watery formulations (like toners or hand washes), and to add water-soluble properties to anhydrous products (like a cleansing oil or bath bombs).

There are many options that have different strengths and weaknesses. Experimenting will help determine why you might use one over the other.

How Solubilizers Work

Solubilizers are similar to emulsifiers in that they have both hydrophilic and lipophilic traits, but solubilizers tend to be completely water-soluble and only a little oil soluble.

In practice, this means they can suspend smaller amounts of oils (think essential oils in perfume or room sprays), and because they are solubilizing only small amounts of oil the entire solution can still appear clear or slightly hazy.

You should use solubilizers when adding just small amounts of oil to a water-based product. When scenting a toner, a spray, a gel, etc., these can be your best friend. It will depend on the specific solubilizer and essential oil you use to determine the ideal ratio of product to emulsifier.

General Guide:

• You’ll need to experiment with your specific solubilizer and your specific oil/essential oil/fragrance oil blend to find the precise ratio to keep everything solubilized and clear as they will vary.
• In a skin care formulation where a solubilizer is required to solubilize essential oils, it is recommend not to eliminate the solubilizer in favour of shaking the end product before each use, the essential oils dont distribute evenly and can this can lead to sensitization due to high essential oil dosing.

Solubilizers

Polysorbate 80

Polysorbate 80 is really useful for solubilizing small amounts of oils into water, like toners or body mists. It can also be used in 100% oil-based products (like cleansing balms or oils) or products that need very low water levels (like bath bombs). In a cleansing balm or oil, it functions as a cleansing/rinse-off-boosting ingredient because one end of the molecule loves oil while the other end loves water; the oil-loving end grabs oil soluble things from the skin and the water-soluble end grabs into the water you’re washing with for easier wash off.

Polysorbate 80 tends to be sticky in leave-on products, so be sure to experiment with your formula to see if the amount you’re using works with the skin feel you want. Polysorbate 80 is best for wash-off products.

Polysorbate 20

Polysorbate 20 is added to water-based cosmetic formulations as the last component required for ensuring that essential oils and fragrance oils remain blended with the bases to which they are added. Its soothing, non-irritating quality makes it ideal for adding to formulations for bath products, for body and facial cleansers, for baby products, and for other transparent and scented products, as it helps retain both the fragrance and the clarity.

Polysorbate 20 in great for non-skin-things (room sprays, hair mists, etc.)

To incorporate Polysorbate 20 into a formulation, blend it with an equal amount of essential oils or fragrance oils for a 1:1 ratio of solubilizer to scent. Blend this combination until it is a clear mixture, then stir it directly into the base to stabilize the essential oils, to ensure that they remain thoroughly combined in the formula, and to help the final product maintain its transparency.

Caprylyl/Capryl Glucoside

C/C glucoside is primarily a surfactant, but it has great solubilizing properties. For this reason, it is used in a lot of liquid foaming products (hand washes, body washes, etc.) as it will both contribute to the lather of the product and solubilize any added essential or fragrance oils. It contains water, so it is not a good solubilizer choice for 100% oil-based products (like cleansing balms or oils) or products that need very low water levels (like bath bombs). It is quite unique among the solubilizers, due to it primarily being a surfactant, so if you need to substitute it out you will need to determine if it is functioning primarily as a surfactant or solubilizer. The alternative suggestion is coco glucoside for the cleansing/lathering with added polysorbate 20 and/or 80 to solubilize whatever the c/c was solubilizing. You’ll also need to pH adjust if you use coco glucoside as it has a much higher pH than c/c glucoside.

Olive Oil PEG-7 Esters (Olivem300)

Olivem 300 can also be called water-soluble olive oil, though not entirely accurate. It does have some solubilizing properties but isn’t a very strong solubilizer. It can be added in anhydrous products that would have some self-emulsifying abilities (like a body/body oil that would self-emulsify with water when applied to damp skin), or in watery products to add some richness too (like a toner). In general, the leave-on feel is far superior to that of the polysorbates, which can be quite sticky. It can be used in cleansing balms, cleansing oils, and bath bombs as well.

PEG 40 hydrogenated castor oil

Peg 40 HC is used in cosmetics as a solubilizer, emulsifier, surfactant, and emollient. It is derived from Castor oil and is useful in producing products that disperse in water whilst offering good moisturizing properties.

Useful as a surfactant (foam booster.) As an emulsifier, solubilizer, and foam booster. O/W emulsifier. Effective solubilizing agent in some essential oils and fragrance oils. 
Miscible in both oils and in water 
Use in a heated oil,  or in cool down phase at 1% to 10%, although it’s safe to use up to 100% (Neat) on skin.