Aminohippuric Acid

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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C₉H₁₀N₂O₃    194.19

Glycine, N-(4-aminobenzoyl)-;

p-Aminohippuric acid CAS RN^®: 61-78-9; UNII: Y79XT83BJ9.

1 DEFINITION

Aminohippuric Acid contains NLT 98.0% and NMT 100.5% of aminohippuric acid (C₉H₁₀N₂O₃ ), calculated on the dried basis.

2 IDENTIFICATION

Change to read:

A. SPECTROSCOPIC IDENTIFICATION TESTS (197), Infrared Spectroscopy: 197K _{(CN 1-MAY-2020)}

B.

Sample: 10 mg of Aminohippuric Acid

Analysis: Dissolve the Sample in 5 mL of water, add 0.5 mL of 3 N hydrochloric acid, 0.5 mL of sodium nitrite solution (1 in 10), and a solution of 0.20 g of 2-naphthol in 10 mL of 6 N ammonium hydroxide.

Acceptance criteria: A red color is produced.

3 ASSAY

PROCEDURE

Sample: 150 mg of Aminohippuric Acid

Analysis: To the Sample add 5 mL of hydrochloric acid and 50 mL of water. Proceed as directed in Nitrite Titration (451), beginning with "stir until dissolved." Each mL of 0.1 M sodium nitrite is equivalent to 19.42 mg of aminohippuric acid (C₉H₁₀N₂O₃ ).

Acceptance criteria: 98.0%-100.5% on the dried basis

4 IMPURITIES

RESIDUE ON IGNITION (281 ): NMT 0.25%

5 SPECIFIC TESTS

LOSS ON DRYING (731).

Analysis: Dry at 105° for 2 h.

Acceptance criteria: NMT 0.25%

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight, light-resistant containers.

USP REFERENCE STANDARDS (11)

USP Aminohirpuric Acid RS.