Anhydrous Formulations – Cosmetic Uses in Water-Free Skin and Body Care

What Are Anhydrous Formulations?

Anhydrous formulations are cosmetic products that contain no intentionally added water. They are generally based on oils, esters, waxes, butters, silicones or other non-aqueous materials.

Common examples include lip balms, lipsticks, facial oils, cleansing oils, body balms, petroleum-based products and certain solid sticks.

Cosmetic Uses of Anhydrous Formulations

Anhydrous systems are particularly useful when a product is designed around oil-soluble ingredients or when a water-free texture is desired. They can also be advantageous for ingredients that are unstable in aqueous environments.

The absence of water can reduce the conditions required for microbial growth. However, an anhydrous product is not automatically microbiologically safe. Water can be introduced during consumer use, particularly in products handled with wet hands or used in the shower.

Stability Considerations

Oxidative stability is often an important consideration in anhydrous formulations. Oils containing high levels of unsaturated fatty acids can oxidise during storage, potentially causing changes in odour, colour and sensory properties.

Antioxidants, oxygen-limiting packaging and appropriate storage conditions may therefore be important for maintaining product stability.

Texture and Processing

In balms and sticks, the selection of waxes and their crystallisation behaviour strongly influences hardness, payoff, melting point and sensory properties.

Cooling conditions can also affect crystal formation and therefore the final texture of the product. Processing temperature and cooling rate should be controlled during development and scale-up.

References

Barel, A. O., Paye, M. and Maibach, H. I. Handbook of Cosmetic Science and Technology. CRC Press.

European Commission. CosIng – Cosmetic Ingredients Database.