Packaging and storage—
Preserve in single-dose or in multiple-dose, light-resistant containers, preferably of Type I glass.
Identification—
Transfer a volume of Injection, equivalent to 5 mg of estradiol cypionate, to a glass-stoppered, 50-mL test tube, and add 30 mL of alcohol. Shake the mixture vigorously for 5 minutes, centrifuge until the two layers have separated, and transfer the alcohol layer, with the aid of a hypodermic syringe, to a 50-mL beaker. Evaporate on a steam bath to dryness, add 5 mL of potassium hydroxide solution (1 in 10), and heat on the steam bath for 15 minutes. Mix 50 mg of sulfanilic acid with 2 mL of 3 N hydrochloric acid, warm the mixture, then cool it in ice water, and slowly add, with agitation, 0.3 mL of sodium nitrite solution (1 in 10). Add this solution to the saponified estradiol cypionate: a red color is produced.
Other requirements—
It meets the requirements under
Injections 
1
.
Assay—
Standard preparation—
Accurately weigh about 10 mg of
USP Estradiol Cypionate RS, and transfer to a 100-mL volumetric flask. Add 10.0 mL of
Internal standard solution, dilute with tetrahydrofuran to volume, and shake vigorously to dissolve.
Assay preparation—
Using a “to contain” pipet, transfer an accurately measured volume, in mL, of Injection, equivalent to about 10 mg of estradiol cypionate, to a 100-mL volumetric flask. Rinse the pipet with small portions of tetrahydrofuran, collecting the washings in the volumetric flask. Add 10.0 mL of Internal standard solution, dilute with tetrahydrofuran to volume, and mix.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Estradiol Cypionate. Calculate the quantity, in mg, of C
26H
36O
3 in each mL of the Injection taken by the formula:
(100C / V)(RU / RS),
in which
C is the concentration, in mg per mL, of
USP Estradiol Cypionate RS in the
Standard preparation; V is the volume, in mL, of Injection taken; and
RU and
RS are the ratios of the peak responses of the estradiol cypionate and internal standard peaks obtained from the
Assay preparation and the
Standard preparation, respectively.
