Phenazopyridine Hydrochloride
;)
2,6-Pyridinediamine,3-(phenylazo)-,monohydrochloride.
2,6-Diamino-3-(phenylazo)pyridine monohydrochloride [136-40-3].
»Phenazopyridine Hydrochloride contains not less than 99.0percent and not more than 101.0percent of C11H11N5·HCl,calculated on the dried basis.
Packaging and storage—
Preserve in tight containers.
Identification—
A:
Infrared Absorption á197Kñ.
Solution:
5µg per mL.
Medium:
sulfuric acid in alcohol (1in 360).
C:
Prepare a solution of it in alcohol containing about 0.2mg per mL.Transfer 10mLof this solution to a glass-stoppered,100-mLgraduated cylinder,add chloroform to volume,and mix.Apply 10µLof the solution so obtained to a suitable thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel.Apply to the same plate 10µLof a Standard solution of USP Phenazopyridine Hydrochloride RSin the same medium having a known concentration of about 0.02mg per mL.Develop the chromatogram in a solvent system consisting of a mixture of chloroform,ethyl acetate,and methanol (85:10:5)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chamber and allow it to dry.Locate the spots by spraying the plate lightly with 2Nhydrochloric acid:the RFof the principal spot in the chromatogram of the test solution corresponds to that obtained from the Standard solution.
Loss on drying á731ñ—
Dry it at 105
for 4hours:it loses not more than 1.0%of its weight.
for 4hours:it loses not more than 1.0%of its weight.
Residue on ignition á281ñ:
not more than 0.2%.
Water-insoluble substances—
Dissolve about 2g,accurately weighed,in 200mLof water,heat to boiling,then heat in a covered container on a steam bath for 1hour.Filter through a tared,fine-porosity,sintered-glass crucible,wash thoroughly with water,and dry at 105to constant weight:the weight of the residue does not exceed 0.1%of the weight of Phenazopyridine Hydrochloride taken.
to constant weight:the weight of the residue does not exceed 0.1%of the weight of Phenazopyridine Hydrochloride taken.
Heavy metals,Method IIá231ñ:
0.002%.
Ordinary impurities á466ñ—
Test solution—
Prepare a solution of it in alcohol having a concentration of 2.0mg per mL.
Standard solutions—
Prepare solutions of USP Phenazopyridine Hydrochloride RSin alcohol containing 0.04,0.02,and 0.01mg per mL,respectively.
Eluant:
a mixture of chloroform,ethyl acetate,and methanol (85:10:5).
Visualization—
Spray the plate with 5Nhydrochloric acid.
Assay—
Transfer about 100mg of Phenazopyridine Hydrochloride,accurately weighed,to a 200-mLvolumetric flask.Add about 100mLof a mixture of sulfuric acid and alcohol (1in 360),heat gently on a steam bath for 10minutes,shake by mechanical means to dissolve,cool to room temperature,dilute with the alcoholic sulfuric acid to volume,and mix.Transfer 10.0mLof this solution to a 100-mLvolumetric flask,dilute with the alcoholic sulfuric acid to volume,and mix.Transfer 5.0mLof the resulting solution to a 50-mLvolumetric flask,dilute with the alcoholic sulfuric acid to volume,and mix.Concomitantly determine the absorbances of this solution and a Standard solution of USP Phenazopyridine Hydrochloride RSin the same medium having a known concentration of about 5µg per mL,in 1-cm cells at the wavelength of maximum absorbance at about 390nm,with a suitable spectrophotometer,using dilute alcoholic sulfuric acid (1in 360)as the blank.Calculate the quantity,in mg,of C11H11N5·HCl in the Phenazopyridine Hydrochloride taken by the formula:
20C(AU/AS),
in which Cis the concentration,in µg per mL,of USP Phenazopyridine Hydrochloride RSin the Standard solution,and AUand ASare the absorbances of the solution of Phenazopyridine Hydrochloride and the Standard solution,respectively.
Auxiliary Information—
Staff Liaison:Daniel K.Bempong,Ph.D.,Scientist
Expert Committee:(PA2)Pharmaceutical Analysis 2
USP28–NF23Page 1524
Phone Number:1-301-816-8143