Triple Sulfa Vaginal Inserts (Monograph under this new title—to become official October 1,2005) (Current monograph title is Triple Sulfa Vaginal Tablets) »Triple Sulfa Vaginal Inserts contain not less than 90.0percent and not more than 110.0percent of the labeled amounts of sulfathiazole (C9H9N3O2S2),sulfacetamide (C8H10N2O3S),and sulfabenzamide (C13H12N2O3S). Packaging and storage— Preserve in well-closed,light-resistant containers. USP Reference standards á11ñ USP Sulfabenzamide RS.USP Sulfacetamide RS.USP Sulfathiazole RS. Identification— The retention times of the major peaks in the chromatogram of the Assay preparationcorrespond to those in the chromatogram of the Standard preparation,as obtained in the Assay. Disintegration á701ñ: 30minutes. Uniformity of dosage units á905ñ: meet the requirements for Weight Variationwith respect to sulfathiazole,to sulfacetamide,and to sulfabenzamide. 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 Inserts.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. Chromatographic system and Procedure— Proceed with the Vaginal Inserts as directed in the Assayunder Triple Sulfa Vaginal Cream. (Official October 1,2005) Auxiliary Information— Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist Expert Committee:(PA7)Pharmaceutical Analysis 7 USP28–NF23Page 1815 Pharmacopeial Forum:Volume No.29(3)Page 670 Phone Number:1-301-816-8394