Assay
Mobile phase,Internal standard solution,and Standard preparation
Prepare as directed in the Assayunder Triple Sulfa Vaginal Cream.
Assay preparation
Weigh and finely powder not fewer than 10Vaginal Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 144mg of sulfacetamide,184mg of sulfabenzamide,and 173mg of sulfathiazole,to a 250-mLvolumetric flask.Add 10.0mLof water,and shake for 10minutes.Add 10.0mLof Internal standard solutionand 100mLof acetone,and shake for 30minutes at low speed on a mechanical shaker.Dilute with acetone to volume,mix,and allow to stand for 30minutes.Pipet 5mLof the clear supernatant into a 50-mLvolumetric flask,and evaporate on a steam bath with the aid of a gentle stream of nitrogen to dryness.Dissolve the residue in Mobile phase,dilute with Mobile phaseto volume,and mix.