Identification—
Place a portion of the stock solution, prepared as directed in the
Assay, containing about 25 mg of miconazole nitrate, in a 50-mL beaker, and evaporate on a steam bath with the aid of a current of filtered air to dryness. Dry the residue at 105
for 10 minutes: the IR absorption spectrum of a potassium bromide dispersion of it so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of
USP Miconazole Nitrate RS.
Assay—
Assay preparation—
Transfer 1 Suppository to a stoppered, 50-mL centrifuge tube. Add 30 mL of pentane, and shake by mechanical means for 20 minutes 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-mL portions 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-mL volumetric flask. Dissolve in methanol, dilute with methanol to volume, and mix. Transfer an accurately measured volume of this stock solution, equivalent to about 5 mg 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 2.0 mL of Internal standard solution.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Miconazole Nitrate Cream. Calculate the quantity, in mg, of miconazole nitrate (C
18H
14Cl
4N
2O·HNO
3) in the Suppository taken by the formula:
(0.2C / V)(RU / RS),
in which
V is the volume, in mL, of stock solution used to prepare the
Assay preparation, and the other terms are as defined therein.
467
:
meet the requirements.