Lufenuron

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

Lufenuron contains NLT 98.0% and NMT 102.0% of lufenuron (C₁₇H₈Cl₂F₈N₂O₃), calculated on the dried basis.

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K (CN 1-May-2020)

B. The retention times of the major peaks of the Sample solution correspond to those of the Standard solution, as obtained in the Assay.

3 ASSAY

Procedure

Solution A: 0.1 mL of phosphoric acid diluted with water to 1 L

Solution B: Acetonitrile

Mobile phase: See Table 1. Return to original conditions, and equilibrate the system.

Table 1

Diluent: Acetonitrile and water (70:30)

System suitability solution: 0.4 mg/mL of USP Lufenuron RS and 0.14 mg/mL of USP Lufenuron Related Compound G RS in Diluent. Sonicate if necessary to facilitate dissolution.

Standard stock solution: 0.4 mg/mL of USP Lufenuron RS in Diluent. Sonicate if necessary to facilitate dissolution.

Standard solution: 0.04 mg/mL of USP Lufenuron RS in Diluent from Standard stock solution

Sample stock solution: 0.4 mg/mL of Lufenuron in Diluent. Sonicate if necessary to facilitate dissolution.

Sample solution: 0.04 mg/mL of Lufenuron in Diluent from Sample stock solution

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 255 nm

Column: 4-mm × 25-cm; 5-μm packing L1

Flow rate: 1 mL/min

Injection volume: 20 μL

System suitability

Samples: System suitability solution and Standard solution

[Note—The relative retention times for lufenuron related compound G and lufenuron are 0.9 and 1.0, respectively.]

Suitability requirements

Resolution: NLT 3.0 between lufenuron related compound G and lufenuron, System suitability solution

Tailing factor: NMT 2.0, Standard solution

Relative standard deviation: NMT 0.73%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of lufenuron (C₁₇H₈Cl₂F₈N₂O₃) in the portion of Lufenuron 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 Lufenuron RS in the Standard solution (mg/mL)

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

Acceptance criteria: 98.0%–102.0% on the dried basis

4 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.1%

Organic Impurities

Mobile phase, Diluent, Standard solution, Chromatographic system, and System suitability: Proceed as directed in the Assay.

Identification solution: 1.2 μg/mL of USP Lufenuron Related Compound B RS and 1.6 μg/mL of USP Lufenuron Related Compound C RS in

Diluent

Diluted standard solution: 0.4 μg/mL of USP Lufenuron RS in Diluent from Standard solution

Sample solution: 0.4 mg/mL of Lufenuron in Diluent. Sonicate if necessary to facilitate dissolution.

Analysis

Samples: Identification solution, Diluted standard solution, and Sample solution

Chromatograph the Identification solution, and identify the components on the basis of their relative retention times, given in Table 2.

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

Result = (r_U/r_S) × (C_S/C_U) × (1/F) × 100

r_U = peak response of each impurity from the Sample solution

r_S = peak response of lufenuron from the Diluted standard solution

C_S = concentration of USP Lufenuron RS in the Diluted standard solution (μg/mL)

/C_U = concentration of Lufenuron in the Sample solution (μg/mL)

F = relative response factor (see Table 2)

Acceptance criteria: See Table 2. The reporting level for impurities is 0.1%.

Table 2

5 SPECIFIC TESTS

Loss on Drying 〈731〉

Analysis: Dry at 105° to constant weight.

Acceptance criteria: NMT 0.5%

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in well-closed containers. Store at room temperature.

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

USP Reference Standards 〈11〉

USP Lufenuron RS

USP Lufenuron Related Compound B RS

N-[(2,5-Dichloro-4-hydroxyphenyl)carbamoyl]-2,6-difluorobenzamide.

C₁₄H₈Cl₂F₂N₂O₃ 361.13

USP Lufenuron Related Compound C RS

N-[3-Chloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenylcarbamoyl]-2,6-difluorobenzamide.

C₁₇H₉ClF₈N₂O₃ 476.71

USP Lufenuron Related Compound G RS

2,5-Dichloro-4-[3-(2,6-difluorobenzoyl)ureido]phenyl phenyl carbonate.

C₂₁H₁₂Cl₂F₂N₂O₅ 481.23