Mafenide Acetate
;)
Benzenesulfonamide,4-(aminomethyl)-,monoacetate.
a-Amino-p-toluenesulfonamide monoacetate [13009-99-9].
»Mafenide Acetate contains not less than 98.0percent and not more than 102.0percent of C7H10N2O2S·C2H4O2,calculated on the anhydrous basis.
Packaging and storage—
Preserve in tight,light-resistant containers.
Identification—
A:
Infrared Absorption á197Kñ.
B:
The RFvalue of the principal spot in the chromatogram of the Identification corresponds to that of Standard preparation Aas obtained in the test for Chromatographic purity.
Melting range á741ñ:
between 162
and 171,but the range between beginning and end of melting does not exceed 4.
and 171,but the range between beginning and end of melting does not exceed 4.
pHá791ñ:
between 6.4and 6.8,in a solution (1in 10).
Water,Method Iá921ñ:
not more than 1.0%.
Residue on ignition á281ñ:
not more than 0.2%.
Selenium á291ñ:
0.003%,a 200-mg test specimen being used.
Heavy metals,Method IIá231ñ:
0.002%.
Chromatographic purity—
Standard solutions—
Dissolve USP Mafenide Acetate RSin methanol,mix to obtain Standard solution Ahaving a known concentration of 500µg per mL,dissolve USP4-Formylbenzenesulfonamide RSin methanol,and mix to obtain Standard solution Dhaving a known concentration of 500µg per mL.Quantitatively dilute portions of these solutions with methanol to obtain Standard solutionshaving the following compositions:
| Standard solution |
Dilution | Concentration (µg RS per mL) |
Percentage (%,for comparison with test specimen) |
| A | (Undiluted) | 500 | 1.0 |
| B | 5in 10 | 250 | 0.5 |
| C | 1in 5 | 100 | 0.2 |
| D | (Undiluted) | 500 | 1.0 |
| E | 5in 10 | 250 | 0.5 |
| F | 1in 5 | 100 | 0.2 |
Test solution—
Dissolve an accurately weighed quantity of Mafenide Acetate in methanol to obtain a solution containing 50mg per mL.
Identification solution—
Quantitatively dilute a portion of the Test solutionwith methanol to obtain a solution containing 500µg per mL.
Ninhydrin solution—
Dissolve 300mg of ninhydrin in 100mLof butyl alcohol,add 3mLof glacial acetic acid,and mix.
Procedure—
Apply separately 5µLof the Test solution,5µLof the Identification solution,and 5µLof each Standard solutionto a suitable thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture.Position the plate in a chromatographic chamber,and develop the chromatograms in a solvent system consisting of a mixture of ethyl acetate,methanol,and isopropylamine (77:20:3)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the developing chamber,mark the solvent front,and allow the solvent to evaporate in warm,circulating air.Examine the plate under short-wavelength UVlight,and compare the intensities of any secondary spots observed in the chromatogram of the Test solutionat the RFvalue corresponding to those of the principal spots in the chromatograms of Standard solutions D,E,and F.Spray the plate with the Ninhydrin solution,heat the plate at 105for 5minutes,and examine the plate.Compare the intensities of any secondary spots observed in the chromatogram of the Test solutionto those of the principal spots in the chromatograms of Standard solutions A,B,and C.No secondary spot,observed by both visualizations,from the chromatogram of the Test solutionis larger or more intense than the principal spots obtained fromStandard solution B(0.5%)andStandard solution E(0.5%),and the sum of the intensities of all secondary spots obtained from the Test solutioncorresponds to not more than 1.0%.
for 5minutes,and examine the plate.Compare the intensities of any secondary spots observed in the chromatogram of the Test solutionto those of the principal spots in the chromatograms of Standard solutions A,B,and C.No secondary spot,observed by both visualizations,from the chromatogram of the Test solutionis larger or more intense than the principal spots obtained fromStandard solution B(0.5%)andStandard solution E(0.5%),and the sum of the intensities of all secondary spots obtained from the Test solutioncorresponds to not more than 1.0%.
Organic volatile impurities,Method Vá467ñ:
meets the requirements.
Assay—
Transfer about 100mg of Mafenide Acetate,accurately weighed,to a 50-mLvolumetric flask,dissolve in about 20mLof water,dilute with water to volume,and mix.Pipet 10mLof this solution into a 100-mLvolumetric flask containing 1mLof 1Nhydrochloric acid,dilute with water to volume,and mix.Dissolve an accurately weighed quantity of USP Mafenide Acetate RSin 0.01Nhydrochloric acid,and dilute quantitatively and stepwise with the same solvent to obtain a Standard solution having a known concentration of about 200µg per mL.Concomitantly determine the absorbance of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 267nm,with a suitable spectrophotometer,using 0.01Nhydrochloric acid as the blank.Calculate the quantity,in mg,of C7H10N2O2S·C2H4O2in the portion of Mafenide Acetate taken by the formula:
0.5C(AU/AS),
in which Cis the concentration,in µg per mL,of USP Mafenide Acetate RSin the Standard solution;and AUand ASare the absorbances of the solution of Mafenide Acetate and the Standard solution,respectively.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1160
Pharmacopeial Forum:Volume No.30(4)Page 1258
Phone Number:1-301-816-8394