Identification—
Transfer a volume of Injectable Suspension, equivalent to about 50 mg of medroxyprogesterone acetate, to a centrifuge tube, centrifuge, decant the supernatant, and wash the solids with two 15-mL portions of water, discarding the water washings. Dissolve the solids in 10 mL of chloroform, transfer to a small beaker, evaporate the chloroform on a steam bath, and dry at 105
for 3 hours: the residue so obtained responds to
Identification test
A under
Medroxyprogesterone Acetate.
Assay—
Mobile phase—
Mix 700 mL of butyl chloride, 300 mL of hexane, both previously saturated with water, and 80 mL of acetonitrile. The acetonitrile concentration may be varied to meet system suitability requirements and to provide elution times of about 12 and 15 minutes for progesterone and medroxyprogesterone acetate, respectively. Pass the solution through a membrane filter (1 µm or finer porosity).
Internal standard solution—
Prepare a solution of progesterone in Mobile phase containing 0.25 mg per mL.
Assay preparation—
Transfer to a suitable container an accurately measured volume of Injectable Suspension, equivalent to about 50 mg of medroxyprogesterone acetate. Pipet 25 mL of chloroform into the container, shake for about 20 minutes, and centrifuge. Pipet 4 mL of the chloroform layer into a suitable container, and evaporate to dryness. Pipet 20 mL of Internal standard solution into the container to dissolve the residue.
Chromatographic system—
The liquid chromatograph is equipped with a 254-nm detector and a 2-mm × 25-cm column that contains 5-µm packing L3. The flow rate is about 2 mL per minute. Chromatograph the
Standard preparation, and record the peak responses as directed for
Procedure: the resolution of progesterone and medroxyprogesterone is not less than 5.0, and the relative standard deviation of the peak responses for replicate injections is not more than 2.0%.
Procedure—
Proceed as directed in the
Assay under
Medroxyprogesterone Acetate. Calculate the quantity, in mg, of medroxyprogeterone acetate (C
24H
34O
4) in each mL of the Injectable Suspension taken by the formula:
125(C / V)(RU / RS),
in which
C is the concentration, in mg, of
USP Medroxyprogesterone Acetate RS in the
Standard preparation;
V is the volume, in mL, of Injectable Suspension taken; and
RU and
RS are the ratios of peak areas of medroxyprogesterone acetate peak to internal standard peak obtained from the
Assay preparation and the
Standard preparation, respectively.
791
:
between 3.0 and 7.0.