3863. Etidronic Acid

Nomenclature

CAS number: 2809-21-4
(1-Hydroxyethylidene)bisphosphonic acid; (1-hydroxyethylidene)diphosphonic acid; ethane-1-hydroxy-1,1-diphosphonic acid; Dequest 2010 (Solutia); Fostex P (Henkel).
C2H8O7P2; mol wt 206.03.
C 11.66%, H 3.91%, O 54.36%, P 30.07%.

Description and references

Bisphosphonate antiresorptive agent. Prepn: H. von Baeyer, K. A. Hofmann, Ber. 30, 1973 (1897); and characterization of the acid and disodium salt: F. Kasparek, Monatsh. Chem. 99, 2016 (1968); B. Blaser et al., Z. Anorg. Allg. Chem. 381, 247 (1971). Use as detergent builder: F. L. Diehl, US 3159581 (1964 to Proctor & Gamble). Determn in pharmaceutical formulations: E. W. Tsai et al., J. Pharm. Biomed. Anal. 11, 513 (1993). Symposium on clinical efficacy in malignancy-related hypercalcemia: Am. J. Med. 82, Suppl 2A, 1-78 (1987). Review of pharmacology and therapeutic efficacy in resorptive bone disease: C. J. Dunn et al., Drugs Aging 5, 446-474 (1994); of clinical safety and efficacy in osteoporosis: T. P. van Staa et al., Pharmacotherapy 18, 1121-1128 (1998).

Chemical structure

Properties

Crystallizes from water as the monohydrate. pK1 1.35 ±0.08; pK2 2.87 ±0.01; pK3 7.03 ±0.01; pK4 11.3. Very sol in water (69% at 20° C). Insol in acetic acid.

Derivative

Disodium salt.

Nomenclature

CAS number: 7414-83-7
Disodium dihydrogen (1-hydroxyethylidene)bis[phosphonate]; etidronate disodium; Didronel (Procter & Gamble); Diphos (Procter & Gamble); Etidron (Abiogen).
C2H6Na2O7P2; mol wt 249.99.
C 9.61%, H 2.42%, Na 18.39%, O 44.80%, P 24.78%.

Properties

Crystallizes from water as the di- or tetrahydrate.

Use

Sequestering and chelating agent; scale and corrosion inhibitor.

Therapeutic Category

Bone resorption inhibitor.

Keywords

Antiosteoporotic; Bone Resorption Inhibitor