Amprolium Soluble Powder

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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Amprolium Soluble Powder

1 DEFINITION

Amprolium Soluble Powder contains NLT 95.0% and NMT 105.0% of the labeled amount of amprolium (C₁₄H₁₉ClN₄·HCl).

2 IDENTIFICATION

Change to read:

A. ▲Spectroscopic Identification Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U▲ (CN 1-May-2020)

Sample solution: 10 µg/mL (filtered) in 0.1 N hydrochloric acid

Acceptance criteria: Meets the requirements

3 ASSAY

Procedure

Diluent: Methanol, acetonitrile, and water (45:5:50)

Mobile phase: 6 g of sodium 1-heptanesulfonate in 500 mL of water. Add 12 mL of glacial acetic acid, 2.0 mL of triethylamine, 450 mL of methanol, and 50 mL of acetonitrile. Pass through a suitable filter of 0.5-µm or finer pore size.

System suitability solution: 0.5 mg/mL of USP Amprolium RS and 0.2 mg/mL of 2-picoline in Diluent

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

Sample solution: Nominally 0.5 mg/mL of amprolium in Diluent, prepared as follows. Transfer a portion of Soluble Powder, equivalent to 50 mg of amprolium, to a 100-mL volumetric flask, add 75 mL of Diluent, and sonicate for 10 min. Allow to cool to room temperature, and dilute with Diluent to volume. Pass through a suitable filter of 0.5-µm or finer pore size, and use the clear filtrate.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 25-cm; packing L13

Flow rate: 0.6 mL/min

Injection volume: 10 µL

System suitability

Sample: System suitability solution

Suitability requirements

Resolution: NLT 7 between amprolium and 2-picoline

Column efficiency: NLT 6500 theoretical plates from the amprolium peak

Tailing factor: NMT 2.3 for the amprolium peak

Relative standard deviation: NMT 1.0% for amprolium

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of amprolium (C₁₄H₁₉ClN₄·HCl) in the portion of Soluble Powder taken:

Result = (r₁/r₂) × (C₁/C₂) × 100

r₁ = peak response from the Sample solution

r₂ = peak response from the Standard solution

C₁ = concentration of USP Amprolium RS in the Standard solution (mg/mL)

C₂ = nominal concentration of amprolium in the Sample solution (mg/mL)

Acceptance criteria: 95.0%–105.0%

4 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

Labeling: Label it to indicate that it is for veterinary use only.

USP Reference Standards 〈11〉

USP Amprolium RS