Pentetic Acid

Basic Information

Name: Pentetic Acid

CAS No: 2-[Bis[2-(bis(carboxymethyl)amino)ethyl]amino]acetic acid [67- 43-6]

Functional Categories

Antimicrobial preservative Chelating agent Sequestering agent Stabilizing agent

1. Nonproprietary Names

USP: Pentetic Acid

2. Synonyms

Acidicum penteticum; N,N-bis[2-[bis(carboxymethyl)amino]ethyl]- glycine; [[(carboxymethyl)imino]bis(ethylenenitrilo)]tetraacetic acid; diethylenetriamine pentaacetic acid; diethylenetriamine- N,N,N0,N0,N00-pentaacetic acid; (diethylenetrinitrilo)pentaacetic acid; DTPA; glycine, N,N-bis[2-[bis(carboxymethyl)amino]ethyl]; pentacarboxymethyl diethylenetriamine; Versenex; ZK-43649.

3. Chemical Name & CAS Registry

2-[Bis[2-(bis(carboxymethyl)amino)ethyl]amino]acetic acid [67- 43-6]

4. Empirical Formula & Molecular Weight

C14H23N3O10 393.35

5. Structural Formula

6. Applications

Pentetic acid is mainly used as a chelating agent in the preparation of imaging and contrast agents for radionuclide and magnetic resonance imaging.(1,2) It is also used as a carrier excipient for neutron-capture isotopes in, for example, radiotherapy.(3) Pentetic acid–isotope complexes have also been considered as model active substances in scintigraphic imaging studies.(4) Pentetic acid has been used to chelate metal ions to reduce formation of reactive oxygen species during lyophilization.(5) See also Table I.

7. Description

Pentetic acid occurs as a white crystalline solid and is almost odorless.

8. Pharmacopeial Specifications

See Table II.

9. Typical Properties

Acidity/alkalinity pH = 2.1–2.5 (1% w/v aqueous solution) for Versenex(7) Melting point 220–2228C Solubility 1 in 200 parts of water at 258C for Versenex(7)

10. Stability & Storage

Pentetic acid should be stored in well-closed containers in a cool, dry place.

11. Incompatibilities

The activity of pentetic acid as a chelating agent may cause unwanted effects in formulations containing metal ions. The desired chelate may be displaced by other ions from the formulation.

12. Method of Manufacture

Pentetic acid is a pentaacetic acid triamine formed during the preparation of the amino carboxylic acid and its salt.(8)

13. Safety

Pentetic acid is used in intrathecal and intravenous injection preparations. The pure form of pentetic acid is moderately toxic by the intraperitoneal route. LD50 (mouse, IP): 0.54 g/kg(9) LD50 (mouse, oral): 4.84 g/kg(10)

14. Handling Precautions

Observe normal precautions appropriate to the circumstances and quantity of the material handled. When heated to decomposition pentetic acid emits acrid smoke and irritating fumes.

15. Regulatory Status

Included in the FDA Inactive Ingredients Database (intrathecal and intravenous injections). Included in intravenous and intra-articular injections licensed in the UK.

16. Related Substances

Calcium trisodium pentetate; pentasodium pentetate; zinc trisodium pentetate. Calcium trisodium pentetate Empirical formula C14H18CaN3Na3O10 Molecular weight 497.35 CAS number [12111-24-9] Synonyms Calcium DTPA; calcium pentetate; calcium trisodium DTPA; pentacin; pentetate calcium trisodium; trisodium calcium diethylenetriaminepentaacetate. Regulatory status Included in the FDA Inactive Ingredients Database (intrathecal and intravenous injections). Safety Calcium trisodium pentetate is moderately toxic by IV and IP routes. When heated to decomposition, it emits toxic fumes. Solubility Soluble in water; practically insoluble in ethanol. Comments The EINECS number for calcium trisodium pentetate is 235-169-1. Pentasodium pentetate Empirical formula C14H18N3Na5O10 Molecular weight 503.25 CAS number [140-01-2] Synonyms DTPAN; pentasodium DTPA; pentetate pentasodium; sodium DTPA. Regulatory status Included in the FDA Inactive Ingredients Database (intravenous injections). Safety Pentasodium pentetate is moderately irritating to the skin and mucous membranes. Comments The EINECS number for pentasodium pentetate is 205-391-3. Zinc trisodium pentetate Synonyms Pentetate zinc trisodium; trisodium zinc diethylenetriaminepentaacetate; zinc DTPA (zinc pentetate or zinc trisodium pentetate). Empirical formula C14H18N3Na3O10Zn Molecular weight 522.7 CAS number [65229-17-6] (zinc pentetate); [125833-02-5] (zinc trisodium pentetate)

17. Comments

The EINECS number for pentetic acid is 200-652-8. The PubChem Compound ID (CID) for pentetic acid is 3053.