Hydrophobic materials generally contain non-polar structures and have limited ability to interact with water.

Many cosmetic oils, waxes and oil-soluble ingredients have predominantly hydrophobic characteristics.

In emulsions, hydrophobic materials are commonly associated with the oil phase.

Formulation Importance

Hydrophobicity is central to understanding emulsification, solubilization and ingredient partitioning.

An ingredient's hydrophobicity can affect where it is located within an emulsion and therefore influence its stability, release and availability.

Amphiphilic Molecules

Many surfactants contain both hydrophilic and hydrophobic regions. These molecules can position themselves at interfaces between oil and water and are therefore particularly important in emulsification.

References

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

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