Testosterone Cypionate Injection

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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Testosterone Cypionate Injection is a sterile solution of Testosterone Cypionate in a suitable vegetable oil. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C₂₇H₄₀O₃. It may contain a suitable solubilizing agent.

1 Packaging and storage

Preserve in single-dose or multiple-dose containers, preferably of Type I glass, protected from light.

USP Reference standards 〈11〉—

USP Cholesteryl Caprylate RS C₃₅H₆₀O₂ 512.86

USP Testosterone Cypionate RS

Identification

Dilute a suitable volume of Injection with chloroform to obtain a solution having a concentration of about 400 μg of testosterone cypionate per mL. Prepare a 20- × 20-cm thin-layer chromatographic plate (see Chromatography 〈621〉), coated with a 0.25-mm layer of chromatographic siliceous earth, by placing it in a developing chamber containing and equilibrated with a mixture of chloroform and corn oil (90:10), and allowing the solvent front to move about three-fourths of the length of the plate. Remove the plate, and allow the chloroform to evaporate. Apply 10 μL each of the solution under test and of a solution of USP Testosterone Cypionate RS in chloroform containing about 400 μg per mL on the plate, on a line about 2.5 cm from the bottom edge and about 1.5 cm apart. Place the plate in a developing chamber that contains and has been equilibrated with a mixture of methanol and water (90:10) previously saturated with corn oil. Develop the chromatogram until the solvent front has moved to about 10 cm above the line of application. Remove the plate, and heat in an oven at 105° for a few minutes. Spray the plate with a mixture of alcohol and sulfuric acid (3:1), and heat in an oven at 105° for 1 to 2 minutes. Observe the plate under long-wavelength UV light: the R value of the principal spot obtained from the solution under test corresponds to that obtained from the Standard solution.

2 Other requirements

It meets the requirements under Injections and Implanted Drug Products 〈1〉.

3 Assay

Internal standard solution and Standard preparation—Prepare as directed in the Assay under Testosterone Cypionate.

Assay preparation—Transfer 1 mL of Injection, accurately measured, into a glass-stoppered, 50-mL centrifuge tube. Add 30 mL of a mixture of methanol and water (9:1), insert the stopper, and shake for 15 minutes. Centrifuge, remove the dilute methanol layer without disturbing the oil, and transfer it to a 200-mL volumetric flask. Repeat the extraction with three additional 30-mL portions of the dilute methanol, collecting the combined extracts in the volumetric flask. Dilute the combined extracts with the dilute methanol to volume, mix, and chill the contents of the flask to −8°. Remove the flask from the freezer, and immediately filter a portion of the contents. Allow the filtrate to reach room temperature, transfer a portion of it, equivalent to about 3 mg of testosterone cypionate, to a suitable vial, and evaporate to dryness. Add by pipet 3 mL of Internal standard solution, and shake vigorously to dissolve the residue.

Procedure—Proceed as directed for Procedure in the Assay under Testosterone Cypionate. Calculate the quantity, in mg, of C₂₇H₄₀O₃ in the portion of Injection taken by the formula:

600(C/V)(R_U/R_S)

in which C is the concentration, in mg per mL, of USP Testosterone Cypionate RS in the Standard preparation; and V is the volume, in mL, of the filtrate used in the Assay preparation.