Flutamide 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

Flutamide Capsules contain NLT 93.0% and NMT 107.0% of the labeled amount of glutamide (C₁₁H₂₂F₃N₂O₃).

2 IDENTIFICATION

A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution as obtained in the Assay. • B. The UV spectrum of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

Procedure

Diluent: Acetonitrile and water (50:50)

Mobile phase: Acetonitrile and water (45:55)

Standard stock solution: 0.5 mg/mL of USP Flutamide RS in Diluent

Standard solution: 0.2 mg/mL of USP Flutamide RS from the Standard stock solution in water

Sample stock solution: Nominally 0.5 mg/mL of flutamide prepared as follows. Remove the contents of NLT 20 Capsules, and mix. Transfer a portion of the powder, equivalent to 125 mg of flutamide, into a 250-mL volumetric ask. Add 180 mL of Diluent and shake the ask for 15 min. Dilute with Diluent to volume, and mix. Allow the insoluble material to settle. The concentration is equivalent to 0.5 mg/mL of flutamide.

Sample solution: Nominally 0.2 mg/mL of utamide prepared as follows. Transfer 20.0 mL of the supernatant from the Sample stock solution into a 50-mL volumetric ask, dilute with water to volume, mix, and pass through a polytef membrane filter of 0.45-µm pore size.

3.1 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 240 nm. For Identification B, use a diode array detector in the range of 210–400 nm.

Column: 4.6-mm × 25-cm; packing L1

Column temperature: 25 ± 5°

Flow rate: 1.0 mL/min

Injection volume: 20 µL

Run time: About two times the retention time of utamide

3.2 System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 2.0

Relative standard deviation: NMT 1.5%

3.3 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of utamide (C₁₁H₂₂F₃N₂O₃) in the portion of Capsules taken:

Result = (r_U /r_S ) × (C_S /C_U) × 100

r_U = peak area from the Sample solution

r_S = peak area from the Standard solution

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

C_U = nominal concentration of utamide in the Sample solution (mg/mL)

Acceptance criteria: 93.0%–107.0%

4 PERFORMANCE TESTS

Dissolution 〈711〉

Medium: 2% sodium lauryl sulfate solution; 1000 mL

Apparatus 2: 75 rpm

Time: 60 min

Standard solution: A known concentration of USP Flutamide RS in Medium

Sample solution: Filter portions of the solution under test. Dilute with Medium as needed.

Instrumental conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.)

Mode: UV

Analytical wavelength: 306 nm

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of utamide (C₁₁H₂₂F₃N₂O₃) dissolved:

Result = (A_U /A_S ) × C_S × D × V × (1/L) × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

C_S = concentration of the Standard solution (mg/mL)

D = dilution factor for the Sample solution

V = volume of Medium, 1000 mL

L = label claim (mg/Capsule)

Tolerances: NLT 75% (Q) of the labeled amount of utamide (C₁₁H₂₂F₃N₂O₃) is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 IMPURITIES

Organic Impurities

Diluent, Mobile phase, Standard solution, Sample solution, and Chromatographic system: Proceed as directed in the Assay. Detector sensitivity solution: 0.2 µg/mL from the Standard solution in a mixture of acetonitrile and water (1:4)

5.1 System suitability

Sample: Detector sensitivity solution

Suitability requirements

Relative standard deviation: NMT 10.0% for utamide

5.2 Analysis

Sample: Sample solution

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

Result = (r_U /r_T ) × 100

r_U = peak area of each impurity from the Sample solution, excluding those where peak areas are less than those of the Detector sensitivity solution

r_T = sum of all the peak responses from the Sample solution

Acceptance criteria

Individual impurities: NMT 0.2% for any impurity having a relative retention time of 0.45; NMT 0.1% for any other impurity Total impurities: NMT 0.3%

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in well-closed, light-resistant containers.

USP Reference Standards 〈11〉

USP Flutamide RS.