Sulfathiazole
;)
Benzenesulfonamide,4-amino-N-2-thiazolyl-.
N1-2-Thiazolylsulfanilamide [72-14-0].
»Sulfathiazole contains not less than 99.0percent and not more than 100.5percent of C9H9N3O2S2,calculated on the dried basis.
Packaging and storage—
Preserve in well-closed,light-resistant containers.
Identification—
A:
Infrared Absorption á197Kñ.
B:
To 100mg add 5mLof 3Nhydrochloric acid,and boil gently for about 5minutes.Cool in an ice bath,add 4mLof sodium nitrite solution (1in 100),dilute with water to 10mL,and place the mixture in an ice bath for 10minutes.To 5mLof the cooled mixture add a solution of 50mg of 2-naphthol in 2mLof sodium hydroxide solution (1in 10):an orange-red precipitate is formed,and it darkens on standing.
Acidity—
Digest 2g with 100mLof water at about 70
for 5minutes,cool at once to about 20,and filter.Titrate 25mLof the filtrate with 0.10Nsodium hydroxide,using 2drops of phenolphthalein TSas the indicator:not more than 0.5mLis required to produce a pink color.(Retain the remainder of the filtrate for the tests for Chloride á221ñand for Sulfate á221ñ.)
for 5minutes,cool at once to about 20,and filter.Titrate 25mLof the filtrate with 0.10Nsodium hydroxide,using 2drops of phenolphthalein TSas the indicator:not more than 0.5mLis required to produce a pink color.(Retain the remainder of the filtrate for the tests for Chloride á221ñand for Sulfate á221ñ.)
Loss on drying á731ñ—
Dry it at 105for 2hours:it loses not more than 0.5%of its weight.
for 2hours:it loses not more than 0.5%of its weight.
Residue on ignition á281ñ:
not more than 0.1%.
Chloride á221ñ—
A25-mLportion of the filtrate prepared as directed in the test for Acidityshows no more chloride than corresponds to 0.10mLof 0.020Nhydrochloric acid (0.014%).
Sulfate á221ñ—
A25-mLportion of the filtrate prepared as directed in the test for Acidityshows no more sulfate than corresponds to 0.2mLof 0.02Nsulfuric acid (0.04%).
Heavy metals,Method IIá231ñ:
0.002%.
Ordinary impurities á466ñ—
Test solution:
methanol.
Standard solution:
methanol.
Eluant:
a mixture of 1-propanol and 1Nammonium hydroxide (22:3).
Visualization:
1.
Assay—
Proceed with Sulfathiazole as directed under Nitrite Titration á451ñ.Each mLof 0.1Msodium nitrite is equivalent to 25.53mg of C9H9N3O2S2.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1835
Phone Number:1-301-816-8394