Oxymetholone

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

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

DOWNLOAD PDF HERE

C₂₁H₃₂O₃ 332.48

Androstan-3-one, 17-hydroxy-2-(hydroxymethylene)-17-methyl-, (5α,17β)-;

17β-Hydroxy-2-(hydroxymethylene)-17α-methyl-5α-androstan-3-one CAS RN®: 434-07-1; UNII: L76T0ZCA8K.

1 DEFINITION

Oxymetholone contains NLT 97.0% and NMT 103.0% of oxymetholone (C H O ), calculated on the dried basis.

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K or 197A (USP 1-May-2021)

Delete the following:

B. Spectroscopic Identification Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U

Sample solution: 10 μg/mL in 0.01 N methanolic sodium hydroxide

Acceptance criteria: Meets the requirements (USP 1-May-2021)

Add the following:

B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay. (USP 1-May-2021)

3 ASSAY

Change to read:

Procedure

[Note - Protect solutions containing oxymetholone from light.]

Diluted acetic acid: Dilute 2 mL of glacial acetic acid with 1 L of water.

Mobile phase: Tetrahydrofuran, acetonitrile, and Diluted acetic acid (32:12:56)

Standard solution: 0.1 mg/mL of USP Oxymetholone RS, prepared as follows. Dissolve a suitable amount of the material with 50% of the flask volume of acetonitrile in an appropriate volumetric flask. Sonicate until completely dissolved. Dilute with water to volume.

Sample solution: 0.1 mg/mL of Oxymetholone, prepared as directed in the Standard solution

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 280 nm

Column: 4.6-mm × 25-cm; 5-μm packing L1

Flow rate: 1.2 mL/min

Injection volume: 20 μL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 1.5

Relative standard deviation: NMT 0.73%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of oxymetholone (C₂₁H₃₂O₃) in the portion of Oxymetholone taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

C_S = concentration of USP Oxymetholone RS in the Standard solution (mg/mL)

C_U = concentration of Oxymetholone in the Sample solution (mg/mL)▲ (USP 1-May-2021)

Acceptance criteria: 97.0%–103.0% on the dried basis

Add the following:

4 IMPURITIES

Organic Impurities

[Note - Protect solutions containing oxymetholone from light.]

System suitability solution: 0.1 mg/mL of USP Oxymetholone RS and 0.02 mg/mL of USP Oxymetholone Related Compound B RS in toluene

Sensitivity solution: 0.001 mg/mL of USP Oxymetholone Related Compound B RS in toluene

Standard solution: 0.01 mg/mL of USP Oxymetholone RS in toluene

Sample solution: 1.0 mg/mL of Oxymetholone in toluene

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: GC

Detector: Flame ionization

Column: 0.32-mm × 30-m capillary; coated with a 0.25-μm film of phase G27

Temperatures

Injection port: 240°

Detector: 325°

Column: See Table 1.

Table 1

Carrier gas: Helium

Flow rate: 1.5 mL/min

Injection volume: 2 μL

Injection type: Split ratio, 5:1

[Note - The use of a deactivated inlet liner is recommended.]

System suitability

Samples: System suitability solution, Sensitivity solution, and Standard solution

[Note - See Table 2 for the relative retention times.]

Suitability requirements

Resolution: NLT 2.0 between oxymetholone and oxymetholone related compound B, System suitability solution

Tailing factor: NMT 1.2 for oxymetholone, Standard solution

Signal-to-noise ratio: NLT 10 for oxymetholone related compound B, Sensitivity solution

Analysis

Sample: Sample solution

Calculate the percentage of each impurity in the portion of Oxymetholone taken:

Result = (r_U/F_i) × {1/[r_T + Σ(r_U/F_i)]} × 100

r_U = peak response of each impurity from the Sample solution

F_i = relative response factor for each corresponding impurity (see Table 2)

r_T = peak response of Oxymetholone from the Sample solution

Acceptance criteria: See Table 2. The reporting threshold is 0.1%.

Table 2

^a 3α,17α-Dimethyl-5α-androstan-3β,17β-diol.

^b 17β-Hydroxy-17α-methyl-5α-androstan-3-one.

^c 2-Formyl-3-methoxy-17α-methyl-5α-androsta-2-en-17β-ol.

5 SPECIFIC TESTS

Delete the following:

 Melting Range or Temperature 〈741〉: 172°–180° (USP 1-May-2021)

Optical Rotation 〈781S〉, Procedures, Specific Rotation

Sample solution: 20 mg/mL in dioxane

Acceptance criteria: +34° to +38°

Loss on Drying 〈731〉

Analysis: Dry under vacuum over phosphorus pentoxide for 4 h.

Acceptance criteria: NMT 1.0%

Delete the following:

Completeness of Solution

Sample solution: 20 mg/mL in dioxane

Acceptance criteria: The solution is clear and free from undissolved solid. (USP 1-May-2021)

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in well-closed containers.

Change to read:

USP Reference Standards 〈11〉

USP Oxymetholone RS

USP Oxymetholone Related Compound B RS

17β-Hydroxy-1-hydroxymethylene-17α-methyl-5α-androstan-3-one.

C₂₁H₃₂O₃ 332.48 (USP 1-May-2021)