Clotrimazole Vaginal Inserts
» Clotrimazole Vaginal Inserts contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of clotrimazole (C22H17ClN2).
Packaging and storage Preserve in well-closed containers.
USP Reference standards 11
USP Clotrimazole Related Compound A RS
Identification Place an amount of finely powdered Vaginal Inserts, equivalent to about 50 mg of clotrimazole, in a screw-capped, 50-mL centrifuge tube. Add 10 mL of chloroform, and shake vigorously for about 2 minutes. Centrifuge to clarify. [noteThe supernatant may remain slightly turbid. ] Proceed as directed in the Identification test under Clotrimazole Cream, except to use a Standard solution of USP Clotrimazole RS in chloroform containing 5 mg per mL.
Disintegration 701: 20 minutes.
Uniformity of dosage units 905: meet the requirements.
Dibasic potassium phosphate solution and Mobile phase Prepare as directed in the Assay under Clotrimazole.
Internal standard solution, Standard preparation, Resolution solution, and Chromatographic system Prepare as directed in the Assay under Clotrimazole Topical Solution.
Assay preparation Weigh and finely powder not fewer than 10 Vaginal Inserts. Transfer an accurately weighed portion of the powder, equivalent to about 100 mg of clotrimazole, to a 50-mL, screw-capped centrifuge tube, add 10.0 mL of Internal standard solution and 15 mL of Mobile phase, rotate for 15 minutes, and centrifuge for 10 minutes. Using a suitable syringe, transfer the supernatant to a 100-mL volumetric flask. Rinse the syringe with 25 mL of Mobile phase, adding the rinsings to the centrifuge tube. Rotate the centrifuge tube for 15 minutes, and centrifuge for 10 minutes. Using a suitable syringe, transfer the supernatant to the 100-mL volumetric flask. Rinse the syringe with 25 mL of Mobile phase, and add the washings to the 100-mL volumetric flask. Dilute with Mobile phase to volume, and mix.
Procedure Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of clotrimazole (C22H17ClN2) in the portion of Vaginal Inserts taken by the formula:
100C(RU / RS)in which C is the concentration, in mg per mL, of USP Clotrimazole RS in the Standard preparation; and RU and RS are the peak response ratios of clotrimazole to testosterone propionate obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2744Pharmacopeial Forum: Volume No. 29(3) Page 623