Methyltestosterone Capsules

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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1 DEFINITION

Methyltestosterone Capsules contain NLT 90.0% and NMT 110.0% of the labeled amount of methyltestosterone (C₂₀H₃₀O₂).

2 IDENTIFICATION

A. Infrared Absorption

Sample: Evaporate to dryness 25 mL of the Sample stock solution from the Assay.

Acceptance criteria: The IR absorption spectrum of a potassium bromide dispersion of the residue so obtained exhibits maxima at the same

wavelengths as those of a similar preparation of USP Methyltestosterone RS.

3 ASSAY

Procedure

Standard solution: 10 µg/mL of USP Methyltestosterone RS in alcohol

Sample stock solution: Nominally 0.2 mg/mL of methyltestosterone prepared as follows. Transfer the equivalent to 10 mg of

methyltestosterone from the contents of NLT 20 Capsules to a 125-mL separator with the aid of about 5 mL of water. Extract with four 20-

mL portions of chloroform,ltering each through chloroform-washed cotton. Evaporate the combined extracts on a steam bath, with the aid

of a current of air, to dryness. Dissolve the residue in alcohol, transfer to a 50-mL volumetric ask, and dilute with alcohol to volume.

Sample solution: Nominally 10 µg/mL of methyltestosterone in alcohol from the Sample stock solution

Instrumental conditions

Mode: UV

Analytical wavelength: Maximum absorbance at about 241 nm

Cell: 1 cm

Blank: Alcohol

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of methyltestosterone (C₂₀H₃₀O₂) in the portion of Capsules taken:

Result = (Aᵤ / Aₛ) × (Cₛ / Cᵤ) × 100

Aᵤ = absorbance of the Sample solution

Aₛ = absorbance of the Standard solution

Cₛ = concentration of USP Methyltestosterone RS in the Standard solution (µg/mL)

Cᵤ = nominal concentration of methyltestosterone in the Sample solution (µg/mL)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Change to read:

Dissolution 〈711〉

▲Test 1▲ (RB 1-Jan-2025)

Medium: Water; 900 mL

Apparatus 1: 100 rpm

Time: 45 min

Standard solution: 10 µg/mL of USP Methyltestosterone RS in Medium

Sample solution: Filter a portion of the solution under test. Dilute with Medium to obtain a solution containing about 10 µg/mL of

methyltestosterone.

Instrumental conditions

Mode: UV

Analytical wavelength: Maximum absorbance at about 248 nm

Blank: Medium

Analysis

Samples: Standard solution and Sample solution

Tolerances: NLT 70% (Q) of the labeled amount of methyltestosterone (C₂₀H₃₀O₂) is dissolved.

▲Test 2: If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.

Medium: 0.1 N hydrochloric acid; 900 mL, deaerated

Apparatus 1: 10-mesh basket, 100 rpm

Time: 15 min

Buffer: Dissolve 1.36 g of potassium phosphate, monobasic in 1 L of water.

Mobile phase: Acetonitrile and Buffer (55:45)

Standard stock solution: 0.28 mg/mL of USP Methyltestosterone RS in methanol. Sonicate to dissolve, if necessary.

Standard solution: 0.011 mg/mL of USP Methyltestosterone RS from Standard stock solution in Medium

Sample solution: Pass a portion of the solution under test through a suitable lter of 1-µm pore size, discarding an appropriate volume of

ltrate so that a consistent result can be obtained.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 241 nm

Column: 4.6-mm × 15-cm; 5-µm packing L1

Temperatures

Autosampler: 5°

Column: 30°

Flow rate: 1.5 mL/min

Injection volume: 50 µL

Run time: NLT 1.8 times the retention time of methyltestosterone

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 1.8

Relative standard deviation: NMT 3.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of methyltestosterone (C₂₀H₃₀O₂) dissolved:

Result = (rᵤ / rₛ) × Cₛ × V × (1 / L) × 100

rᵤ = peak response of methyltestosterone from the Sample solution

rₛ = peak response of methyltestosterone from the Standard solution

Cₛ = concentration of USP Methyltestosterone RS in the Standard solution (mg/mL)

V = volume of the Medium, 900 mL

L = label claim (mg/Capsule)

Tolerances: NLT 80% (Q) of the labeled amount of methyltestosterone (C₂₀H₃₀O₂) is dissolved. ▲ (RB 1-Jan-2025)

Uniformity of Dosage Units 〈905〉: Meet the requirements

Procedure for content uniformity

Standard solution: 0.010 mg/mL of USP Methyltestosterone RS in methanol

Sample stock solution: Transfer the contents of 1 Capsule to a 100-mL volumetric ask. Add 50 mL of methanol, and shake by mechanical

means for 60 min. Dilute with methanol to volume, and lter, discarding the rst 20 mL of the ltrate.

Sample solution: Dilute a suitable volume of the Sample stock solution with methanol to obtain 0.010 mg/mL of methyltestosterone.

Instrumental conditions

Mode: UV

Analytical wavelength: Maximum absorbance at about 241 nm

Cell: 1 cm

Blank: Methanol

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of methyltestosterone (C₂₀H₃₀O₂) in the Capsule taken:

Result = (Aᵤ / Aₛ) × (Cₛ / L) × V × D × 100

Aᵤ = absorbance of methyltestosterone from the Sample solution

Aₛ = absorbance of methyltestosterone from the Standard solution

Cₛ = concentration of USP Methyltestosterone RS in the Standard solution (mg/mL)

L = label claim (mg/Capsule)

V = volume of the Sample solution (mL)

D = dilution factor of the Sample solution

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in well-closed containers.

Add the following:

▲Labeling: The labeling states the Dissolution test used only if Test 1 is not used.▲ (RB 1-Jan-2025)

USP Reference Standards 〈11〉

USP Methyltestosterone RS