Products
Pure sodium citrate is available in pharmacies and drugstores. It is included in various drugs as an excipient or as an active ingredient. This article refers to trisodium citrate.
Structure and properties
Sodium citrate (C6H5Na3O7, Mr = 258.07 g/mol) is the trisodium salt of citric acid. The pharmacopoeia defines the dihydrate. It exists as a white crystalline powder or as white granular crystals and is readily soluble in water. Aqueous solutions react slightly basic. Sodium citrate can be obtained by neutralizing citric acid with a base such as sodium hydroxide:
- C6H8O7 (citric acid) + 3 NaOH (sodium hydroxide) C6H5Na3O7 (sodium citrate) + 3 H2O (water)
Effects
As an active ingredient, citrate inhibits blood clotting. The effects are due to the complexation of calcium, which is thus no longer available for the blood clotting cascade.
Indications
- As a pharmaceutical excipient, for example, for the preparation of buffers with the citric acid. As an acidity regulator.
- For regional citrate anticoagulation.
- As a food additive (E 331).
- For cleaning crystals.