Sulfadiazine
;)
Benzenesulfonamide,4-amino-N-2-pyrimidinyl-.
N1-2-Pyrimidinylsulfanilamide [68-35-9].
»Sulfadiazine contains not less than 98.0percent and not more than 102.0percent of C10H10N4O2S,calculated on the dried basis.
Packaging and storage—
Preserve in well-closed,light-resistant containers.
Clarity and color of solution—
Dissolve 1g in a mixture of 20mLof water and 5mLof 1Nsodium hydroxide.The solution is clear and not more deeply colored than pale yellow.
Identification—
A:
Infrared Absorption á197Kñ.
B:
Carefully melt about 50mg in a small test tube:a reddish brown color develops.The fumes evolved during the decomposition do not discolor moistened lead acetate test paper (distinction from sulfathiazole).
C:
Gently heat about 1g in a small test tube until a sublimate is formed.Collect a few mg of the sublimate with a glass rod,and mix in a test tube with 1mLof a 1in 20solution of resorcinol in alcohol.Add 1mLof sulfuric acid,and mix by shaking:a deep red color appears at once.Cautiously dilute the mixture with 25mLof ice-cold water,and add an excess of 6Nammonium hydroxide:a blue or reddish blue color is produced.
Acidity—
Digest 2.00g with 100mLof water at about 70
for 5minutes.Cool at once to room temperature,and filter.To 25.0mLof the filtrate add 2drops of phenolphthalein TS,and titrate with 0.10Nsodium hydroxide:not more than 0.20mLis required to produce a pink color.
for 5minutes.Cool at once to room temperature,and filter.To 25.0mLof the filtrate add 2drops of phenolphthalein TS,and titrate with 0.10Nsodium hydroxide:not more than 0.20mLis required to produce a pink color.
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%.
Selenium á291ñ:
0.003%,a 200-mg test specimen being used.
Heavy metals,Method IIá231ñ:
0.002%.
Ordinary impurities á466ñ—
Test solution:
8.3mg per mL,in a mixture of toluene and dimethylformamide (2:1).
Standard solutions:
0.008,0.041,0.08,and 0.17mg per mL,in a mixture of toluene and dimethylformamide (2:1).
Eluant:
a mixture of chloroform,methanol,and ammonium hydroxide (30:12:1).
Visualization:
11.
Assay—
Mobile phase—
Prepare a suitable degassed solution of water,acetonitrile,and glacial acetic acid (87:12:1).
Standard preparation—
Dissolve an accurately weighed quantity of USP Sulfadiazine RSin 0.025Nsodium hydroxide to obtain a solution having a known concentration of about 1mg per mL.
Assay preparation—
Transfer about 100mg of Sulfadiazine,accurately weighed,to a 100-mLvolumetric flask,add 0.025Nsodium hydroxide to volume,and mix.
Chromatographic system
(see Chromatography á621ñ)—The liquid chromatograph is equipped with a 254-nm detector and a 4-mm ×30-cm column that contains packing L1.The flow rate is about 2mLper minute.Chromatograph five replicate injections of the Standard preparation,and record the peak responses as directed for Procedure:the relative standard deviation is not more than 2.0%,and the tailing factor for sulfadiazine is not more than 1.5.
Procedure—
Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C10H10N4O2Sin the portion of Sulfadiazine taken by the formula:
100C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Sulfadiazine RSin the Standard preparation;and rUand rSare the peak responses for sulfadiazine obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1820
Phone Number:1-301-816-8394