Conditioning agents

Shampooing with pure anionic surfactants can leave hair difficult to comb while wet, and prone to ‘fly-away’ when combed after drying. Improvement of the wet-combability and reduction of static charge build-up can be achieved by addition of conditioning agents. These are especially effective if the formulation also contains amphoteric surfactants such as betaines or amine oxides. Cationic surfactants used in hair rinses are normally incompatible with anionic surfactants and cannot be used in shampoo formulations. This problem can be overcome by the use of quaternized polymers. An example is Polyquaternium 10, a quaternized hydroxyethyl cellulose, which is compatible with most of the anionic surfactants and can therefore also be used in clear formulations. It shows excellent conditioning properties and imparts manageability and body to hair. Due to its very high substantivity to hair, very low concentrations (below 0.5%) are sufficient. Use of high concentrations may lead to over-conditioning and build-up on the hair. Used in shower- or foam-bath formulations, polyquaternium 10 can improve skin-feel after use. Other important polyquats are Polyquaternium 7, Polyquaternium 23, Polyquaternium 8, and Polyquaternium II (CTFA nomenclature).
Small amounts of fatty components such as fatty alcohols or monoglycerides can support the conditioning effect of shampoos. Silicones can be very effective conditioners but are difficult to incorporate and may act as antifoaming agents.