Tetrasodium EDTA (Sodium edetate or Tetrasodium Ethylenediaminetetraacetate) is a chemical compound, the tetrasodium salt of ethylenediaminetetraacetic acid and is obtained by the reaction of a basic solution of ethylenediamine with formaldehyde and sodium or hydrogenanide with subsequent hydrolysis and formation of the salt.

EDTA = ethylenediamine tetraacetic acid

The name defines the structure of the molecule:

• Tetrasodium indicates that there are four sodium atoms in the molecule.
• EDTA stands for ethylenediaminetetraacetic acid, a polyamine carboxylic acid that has the ability to bind metal ions.

The synthesis process takes place in several stages:

• Preparation of precursors. The main precursors for the synthesis of EDTA are typically ethylenediamine, formaldehyde and sodium cyanide.
• Condensation reaction. Precursors react together in a condensation reaction with the formation of multiple bonds and the release of water at elevated temperatures.
• Hydrolysis. The cyanide groups in the intermediate product are then hydrolysed into carboxylated groups, forming EDTA.
• Neutralization. EDTA is neutralized with sodium hydroxide (NaOH) to produce tetrasodium EDTA. This reaction involves the formation of a salt from the acid (EDTA) and the base (NaOH). The reaction is typically carried out in an aqueous solution.
• Crystallization. Tetrasodium EDTA is isolated from the crystallization reaction mixture by cooling the reaction mixture to induce the formation of tetrasodium EDTA crystals.
• Filtration and Drying. Tetrasodium EDTA crystals are separated from the reaction mixture by filtration and dried to remove all remaining water.
• Quality control test. The final product is tested to ensure it meets the required specifications. This may involve testing for purity, chelating ability, and other physical and chemical properties.

It appears in the form of a whitish or yellow powder.

Cosmetics

Chelating agent. It has the function of preventing unstable reactions and improving the bioavailability of chemical components within a product, and removes calcium and magnesium cations that can cause cloudiness in clear liquids.

Pharmaceuticals

Tetrasodium EDTA has the function of avoiding unstable reactions of other chemical components inside a product, it is therefore what is called a "chelating" product and with a high affinity for calcium. Effective stabiliser in sulfacetamide solutions and added as a sequestering agent in aqueous formulations.

Medical

It is used parenterally and in therapy for children with iron deficiency anaemia (1)  and in the treatment of children with iron deficiency anaemia (2). In disorders of calcium metabolism, sodium edetate has a chelating function and, by intravenous injection, produces hypocalcaemia (3) It is also effective against organisms associated with biofilms (4).

Other uses

Sodium edetate can replace urea in the traditional printing paste of reactive dyes, using a fixed amount of sodium alginate as a thickening agent (5).

Safety

The EFSA Panel believes that EDTA, Calcium DisodiumEDTA, Diammonium EDTA, Dipotassium EDTA, DisodiumEDTA, TEA-EDTA, Tetrasodium EDTA, Tripotassium EDTA,Trisodium EDTA, HEDTA, and Trisodium HEDTA are safe when used in cosmetic formulations (6).

The most relevant studies on this chemical compound have been selected with a summary of their contents:

Tetrasodium EDTA studies

• Molecular Formula: C₁₀H₁₂N₂O₈Na₄  C₁₀H₁₂N₂Na₄O₈
• Linear Formula: ((NaOOCCH2)2NCH2)2
• Molecular Weight: 380.171 g/mol
• CAS: 64-02-8  67401-50-7  8013-51-2
• EC Number:200-573-9  614-059-0  616-941-0
• UNIII: MP1J8420LU

Synonyms:

• Sodium edetate
• Ethylenediaminetetraacetic acid tetrasodium salt
• EDTA tetrasodium
• Edetate sodium
• Sequestrene
• Aquamollin
• Sodium EDTA
• Complexone
• Tetrasodium edetate

References_____________________________________________________________________

(1) Griffith, D. E. "Improvement of the color stability of parenteral solutions of papaverine hydrochloride." Journal of Pharmaceutical Sciences 56, no. 9 (1967): 1197-1198.

(2) Moningkey, C., Mantik, M.F. and Pateda, V., 2015. Ferric sodium edetate therapy in children with iron deficiency anemia. Paediatrica Indonesiana, 55(2), pp.91-4.

Abstract. Background Iron deficiency anemia (IDA) is frequently found in school-aged children. The main treatments for IDA are overcoming the causal factors and iron supplementation. Noncompliance in taking iron tablets and the possibility of iron absorbtion or transport difficulties, can reduce efficacy of daily oral iron supplementation. Because excess iron storage in the intestinal cells can lead to mucosal blockage, twice weekly oral iron therapy may be considered instead of daily dosage.Objective To compare the effects of daily vs. twice weekly ferric sodium edetate (NaFeEDTA) on hemoglobin (Hb), hematocrit (Ht), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) levels on children with IDA.Methods We conducted an open-label, randomized, prospective study in 36 children with IDA aged 5-11 years. Subjects were divided into two groups. For a one-month period, group I received daily iron therapy (NaFeEDTA) and group II received twice weekly iron therapy. Examinations of Hb, Ht, MCV, MCH, MCHC were performed before and after iron therapy. Results There were no significant differences in Hb, Ht, MCV, MCH or MCHC levels after therapy between the daily and twice weekly NaFeEDTA groups (P > 0.05). Conclusion Twice weekly NaFeEDTA therapy is as effective as daily NaFeEDTA administration in children with IDA. [Paediatr Indones. 2015;55:91-4.]

(3) Clark, F.C., 1982. DISORDERS OF CALCIUM METABOLISM. Adverse Drug Reaction Bulletin, 93(1), pp.340-343.

(4) Percival, S.L., Kite, P., Eastwood, K., Murga, R., Carr, J., Arduino, M.J. and Donlan, R.M., 2005. Tetrasodium EDTA as a novel central venous catheter lock solution against biofilm. Infection Control & Hospital Epidemiology, 26(6), pp.515-519.

Abstract. Central venous catheter (CVC)-related bloodstream infections (BSIs) are known to increase rates of morbidity and mortality in both inpatients and outpatients, including hematology-oncology patients and those undergoing hemodialysis or home infusion therapy. Biofilm-associated organisms on the lumens of these catheters have reduced susceptibility to antimicrobial chemotherapy. This study tested the efficacy of tetrasodium EDTA as a catheter lock solution on biofilms of several clinically relevant microorganisms. Methods: Biofilms of Staphylococcus epidermidis, methicillin-resistant S. aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Candida albicans were grown to levels of approximately 1 × 105 colony-forming units (CFU)/cm−1 on CVC segments in a model system, then subjected to the tetrasodium EDTA lock treatment. Results: Comparisons of biofilms before and after exposure to the 40-mg/mL−1 tetrasodium EDTA lock for 21 hours showed that the biofilm viable cell counts of all organisms tested were significantly reduced (P < .05) after exposure to the treatment. Conclusion: Antimicrobial lock treatment using 40 mg/mL−1 of tetrasodium EDTA for at least 21 hours could significantly reduce or potentially eradicate CVC-associated bio-films of clinically relevant microorganisms (Infect Control Hosp Epidemiol 2005;26:515-519).

(5) El-Molla, M.M., 2019. Innovative technologies for enhancing the printing performance of textile fabrics: a review.

(6) Lanigan RS, Yamarik TA. Final report on the safety assessment of EDTA, calcium disodium EDTA, diammonium EDTA, dipotassium EDTA, disodium EDTA, TEA-EDTA, tetrasodium EDTA, tripotassium EDTA, trisodium EDTA, HEDTA, and trisodium HEDTA. Int J Toxicol. 2002;21 Suppl 2:95-142. doi: 10.1080/10915810290096522.