In cosmetology, the various formulas developed to treat the skin on the surface or in depth are made up of several ingredients. Among the Alpha-Hydroxy-Acids or AHA, you will find citric acid which contains sodium citrate. The latter is generally used to regulate the pH of skincare products.
What is "Sodium Citrate" and what is its utility?
Published on February 1, 2024, by Stéphanie, PhD, Doctorate in Life and Health Sciences — 3 min of reading
What is sodium citrate?
Known by its INCI (International Nomenclature of Cosmetic Ingredients) name Sodium Nitrate, Sodium Citrate is one of the sodium salts found in citric acid. It is also referred to as Trisodium Citrate. Generally, citric acid is present in the majority of fruits, but on an industrial scale, it is extracted from the Aspergillus Niger fungus that is cultured and micro-fermented on a sugary solution. It can also be obtained through the synthesis of chemical agents or through the biotechnology of plant-based raw materials such as corn, tapioca, cassava, or sweet potato.
For domestic use, citric acid, which contains sodium citrate, is used for descaling various types of electrical appliances or different surfaces, such as coffee machines, kettles, taps, or surfaces made of chrome, ceramic, or steel. It is also a component in non-alcoholic refreshing beverages. In the field of cosmetology, citric acid is incorporated into exfoliating skincare treatments.
Sodium Citrate: Its Utility
The sodium salt of citric acid is typically used as a pH regulator in skincare. Its role is to stabilise or adjust the pH of a formula in order to neutralise unpleasant odours or the proliferation of potential bacteria that may embed themselves. This ingredient also corrects excessively high pH in foaming skincare products.
Sodium citrate also serves as a chelating agent in skincare products such as creams, washes, and others. It has the ability to bind positive ions to form a stable complex known as a chelate, which prevents interaction between metallic cations and other ingredients in the product. Without the chelating agent, the cations can alter the stability of the emulsion as well as the pH of the formula, indirectly promoting oxidation or rancidity of the product.
Sodium citrate also acts as a masking agent that reduces and/or conceals the base odour of the skincare product.
Citric Acid: In which skincare products?
Citric acid is found in the majority of beauty treatments. In terms of those intended for the skin, you will find this ingredient in the formulas used regularly. For instance, it is included in the list of constituent ingredients of a serum designed for the treatment of blemish-prone skin. Besides its properties in pH regulation, chelation or masking, citric acid contributes to the effectiveness of the other ingredients in the treatment. Acting against bacteria, it reduces and prevents the establishment of spots, the blockage of pores and the appearance of blackheads by working in conjunction with salicylic acid and/or zinc, for example. Citric acid can also be among the ingredients of a treatment indicated for oily skin or skin prone to acne.
