Methenamine Hippurate
;)
Glycine,N-benzoyl,compd.with 1,3,5,7-tetraazatricyclo[3.3.1.13,7]decane (1:1).
Hexamethylenetetramine monohippurate [5714-73-8].
»Methenamine Hippurate,dried in vacuum at 60
for 1hour,contains not less than 95.5percent and not more than 102.0percent of C6H12N4·C9H9NO3,and contains not less than 54.0percent and not more than 58.0percent of hippuric acid (C9H9NO3).
for 1hour,contains not less than 95.5percent and not more than 102.0percent of C6H12N4·C9H9NO3,and contains not less than 54.0percent and not more than 58.0percent of hippuric acid (C9H9NO3).
Packaging and storage—
Preserve in well-closed containers.
Identification,Infrared Absorption á197Mñ.
Loss on drying á731ñ—
Dry it in vacuum at 60for 1hour:it loses not more than 1.0%of its weight.
for 1hour:it loses not more than 1.0%of its weight.
Residue on ignition á281ñ:
not more than 0.1%.
Sulfate—
Dissolve 200mg in 10mLof water,and add 5drops of 3Nhydrochloric acid and 5drops of barium chloride TS:no turbidity appears within 1minute.
Heavy metals,Method IIá231ñ:
0.0015%.
Organic volatile impurities,Method Iá467ñ:
meets the requirements.
Hippuric acid content—
Transfer about 1g,accurately weighed,to a 250-mLconical flask,and add 50mLof water.When solution is complete,add phenolphthalein TS,and titrate with 0.1Nsodium hydroxide VS.Each mLof 0.1Nsodium hydroxide is equivalent to 17.92of C9H9NO3.
Assay—
Dissolve about 700mg of Methenamine Hippurate,accurately weighed,in 50mLof glacial acetic acid,and titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 31.94mg of C6H12N4·C9H9NO3.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1242
Phone Number:1-301-816-8394