C4H6O4 118.09
Butanedioic acid [110-15-6].

Packaging and storage— Preserve in a well-closed container. No storage requirements specified.NF24

Identification— Place a drop of a saturated solution of the sample in a micro test tube, and add a drop of ammonium chloride solution (0.5 in 100) and several mg of zinc powder. Cover the mouth of the tube with a disk of filter paper moistened with a solution in hexane containing p-dimethylaminobenzaldehyde (5 in 100) and trichloroacetic acid (20 in 100). Heat with a small flame for about 1 minute: a pink to red-violet stain appears on the paper.

Melting range 741: between 185.0 and 190.0.

Residue on ignition 281: not more than 0.025%.

Heavy metals, Method I 231: 0.002%.

Residual solvents 467: meets the requirements.

Assay— Dissolve about 250 mg, accurately weighed, in 25 mL of carbon dioxide-free water. Add 2 drops of phenolphthalein TS and titrate with 0.1 N sodium hydroxide VS to the production of a permanent pink color. Each mL of 0.1 N sodium hydroxide is equivalent to 5.905 mg of C4H6O4.

Expert Committee : (EM105) Excipient Monographs 1

USP29–NF24 Page 3442

Phone Number : 1-301-816-8262