Shampoos are available in a wide variety of formulations; however, commercially available shampoos predominantly take the form of liquid shampoos. Most liquid shampoos contain the following structural components, among which surfactants, foam stabilizers, thickeners, preservatives, and fragrances constitute the essential ingredients. The inclusion of other ingredients in a shampoo depends on consumer needs and cost-effectiveness considerations.
1. Primary Surfactants
Anionic surfactants are the most commonly used primary surfactants in shampoos, such as lauryl sulfates (AS), lauryl ether sulfates (AES), sulfosuccinates, etc.
2. Auxiliary Surfactants
Examples include amine oxides, alkanolamides, imidazolines, etc.
3. Conditioning Agents
Examples include cationic guar gum, emulsified silicone oils, etc.
4. Thickeners and Dispersion Stabilizers
Examples include electrolytes (sodium chloride, ammonium chloride), water-soluble polymers, etc.
5. Pearlescent Agents: Ethylene glycol (mono/di)stearate
6. Chelating Agents: EDTA-Na2, EDTA-Na4
7. Acidity Regulators: Citric acid, lactic acid
8. Others: Colorants, fragrances, preservatives, functional ingredients, etc.
