C6H12N4·C9H9NO3 319.36

Glycine, N-benzoyl, compd. with 1,3,5,7-tetraazatricyclo[3.3.1.13,7]decane (1:1).

Hexamethylenetetramine monohippurate [5714-73-8].

Packaging and storage— Preserve in well-closed containers.

USP Reference standards 11— USP Methenamine Hippurate RS.

Identification, Infrared Absorption 197M.

Loss on drying 731— Dry it in vacuum at 60 for 1 hour: it loses not more than 1.0% of its weight.

Residue on ignition 281: not more than 0.1%.

Sulfate— Dissolve 200 mg in 10 mL of water, and add 5 drops of 3 N hydrochloric acid and 5 drops of barium chloride TS: no turbidity appears within 1 minute.

Heavy metals, Method II 231: 0.0015%.

Organic volatile impurities, Method I 467: meets the requirements.

Hippuric acid content— Transfer about 1 g, accurately weighed, to a 250-mL conical flask, and add 50 mL of water. When solution is complete, add phenolphthalein TS, and titrate with 0.1 N sodium hydroxide VS. Each mL of 0.1 N sodium hydroxide is equivalent to 17.92 of C9H9NO3.

Residual solvents 467: meets the requirements.

Assay— Dissolve about 700 mg of Methenamine Hippurate, accurately weighed, in 50 mL of glacial acetic acid, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 31.94 mg of C6H12N4·C9H9NO3.

Expert Committee : (MDAA05) Monograph Development-Antivirals and Antimicrobials

USP29–NF24 Page 1376

Phone Number : 1-301-816-8394