Estradiol Cypionate Injection
» Estradiol Cypionate Injection is a sterile solution of Estradiol Cypionate in a suitable oil. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C26H36O3.
Packaging and storage— Preserve in single-dose or in multiple-dose, light-resistant containers, preferably of Type I glass.
USP Reference standards 11
USP Estradiol Cypionate RS Click to View Structure
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.
Mobile Phase and Internal standard solution Prepare as directed in the Assay under Estradiol Cypionate.
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 C26H36O3 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.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Domenick Vicchio, Ph.D.
Senior Scientific Liaison
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
USP35–NF30 Page 3107