Internal standard solution, Standard preparation,and Chromatographic system—Prepare as directed in the Assayunder Miconazole Nitrate Cream.

Assay preparation— Transfer 1Suppository to a stoppered,50-mLcentrifuge tube.Add 30mLof pentane,and shake by mechanical means for 20minutes to dissolve the suppository base and to disperse the miconazole nitrate.Centrifuge to obtain a clear supernatant.Aspirate and discard the clear liquid.Wash the residue with three 20-mLportions of pentane,shaking,centrifuging,and aspirating in the same manner.Discard the pentane washings.Evaporate the residual pentane from the residue with the aid of a current of filtered air.Using small portions of methanol,transfer the residue to a 100-mLvolumetric flask.Dissolve in methanol,dilute with methanol to volume,and mix.Transfer an accurately measured volume of this stock solution,equivalent to about 5mg of miconazole nitrate,to a suitable container,and evaporate on a steam bath with the aid of a current of filtered air to dryness.Dissolve the residue in 2.0mLof Internal standard solution.

Procedure— Proceed as directed for Procedurein the Assayunder Miconazole Nitrate Cream.Calculate the quantity,in mg,of miconazole nitrate (C18H14Cl4N2O·HNO3)in the Suppository taken by the formula: in which Vis the volume,in mL,of stock solution used to prepare the Assay preparation,and the other terms are as defined therein.