USP Monographs: Histamine Phosphate

Histamine Phosphate

C5H9N3·2H3PO4

307.14

1H-Imidazole-4-ethanamine, phosphate (1:2).
Histamine phosphate (1:2)

[51-74-1].

» Histamine Phosphate contains not less than 98.0 percent and not more than 101.0 percent of C5H9N3·2H3PO4, calculated on the dried basis.

Packaging and storage— Preserve in tight, light-resistant containers.

Identification—

A: Dissolve 0.10 g in a mixture of 7 mL of water and 3 mL of 1 N sodium hydroxide, and add the solution to a mixture of 50 mg of sulfanilic acid, 10 mL of water, 2 drops of hydrochloric acid, and 2 drops of sodium nitrite solution (1 in 10): a deep red color is produced.

B: Dissolve 50 mg in 5 mL of hot water, add a hot solution of 50 mg of picrolonic acid in 10 mL of alcohol, and allow to crystallize. Filter the crystals with suction, wash with a small amount of ice-cold water, and dry at 105

for 1 hour: the crystals so obtained melt between 250

and 254

, with decomposition.

C: A solution (1 in 10) responds to the tests for Phosphate

191

Loss on drying

731

— Dry it at 105

for 2 hours: it loses not more than 3.0% of its weight.

Residual solvents

467

: meets the requirements.

(Official January 1, 2007)

Assay— Dissolve about 150 mg, accurately weighed, of Histamine Phosphate in 10 mL of water. Add 5 mL of chloroform and 25 mL of alcohol, then add 10 drops of thymolphthalein TS, and titrate with 0.2 N sodium hydroxide VS. Each mL of 0.2 N sodium hydroxide is equivalent to 15.36 mg of C5H9N3·2H3PO4.

Auxiliary Information— Staff Liaison : Elena Gonikberg, Ph.D., Scientist

Expert Committee : (MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine

USP29–NF24 Page 1052

Pharmacopeial Forum : Volume No. 29(5) Page 1504

Phone Number : 1-301-816-8251


Search USP29