Ensulizole
;)
1H-Benzimidazole-5-sulfonic acid-2-phenyl-.
2-Phenylbenzimidazole-5-sulfonic acid [27503-81-7].
»Ensulizole contains not less than 98.0percent and not more than 102.0percent of C13H10N2O3S,calculated on the dried basis.
Packaging and storage—
Preserve in tight containers in a cool place.
USP Reference standards á11ñ—
USP Ensulizole RS.
Identification—
A:
Infrared Absorption á197Kñ.
Solution:
5µg per mL,prepared as follows.Transfer about 100mg of Ensulizole,accurately weighed,to a 100-mLvolumetric flask,dissolve in 4mLof 1Nsodium hydroxide,and dilute with water to volume.Transfer 0.5mLof the solution to a 100-mLvolumetric flask,dilute with water to volume,and mix.Absorptivities,calculated on the dried basis,at the wavelength of maximum absorbance at about 302nm,do not differ by more than 3.0%.
Loss on drying á731ñ—
Dry it at 105
for 4hours:it loses not more than 2.0%of its weight.
for 4hours:it loses not more than 2.0%of its weight.
Assay—
Transfer about 1200mg of Ensulizole,accurately weighed,to a 300-mLiodine flask,and dissolve by stirring in 25mLof 0.5Nsodium hydroxide.Add phenolphthalein TS,and titrate the excess with 0.5Nhydrochloric acid VS.Perform a blank determination,and make any necessary correction.Each mLof 0.5Nsodium hydroxide is equivalent to 137.15mg of C13H10N2O3S.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 735
Pharmacopeial Forum:Volume No.30(4)Page 1191
Phone Number:1-301-816-8394