Diflorasone Diacetate

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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C₂₆H₃₂F₂O₇              494.52

Pregna-1,4-diene-3,20-dione, 17,21-bis(acetyloxy)-6,9-difluoro-11-hydroxy-16-methyl-, (6α,11β,16β)-;

6α,9-Difluoro-11β,17,21-trihydroxy-16β-methylpregna-1,4-diene-3,20-dione 17,21-diacetate CAS RN^®: 33564-31-7; UNII: 7W2J09SCWX.

1 DEFINITION

Diflorasone Diacetate contains NLT 97.0% and NMT 103.0% of diflorasone diacetate (C₂₆H₃₂F₂O₇), calculated on the dried basis. 

2 IDENTIFICATION

Change to read:

A. ^▲SPECTROSCOPIC IDENTIFICATION TESTS (197), Infrared Spectroscopy: 197M _{▲(CN 1-MAY-2020)}

3 ASSAY

3.1 PROCEDURE

Mobile phase: Tetrahydrofuran, glacial acetic acid, water-saturated n-butyl chloride, and water-saturated methylene chloride (10:15:350:125)

Internal standard solution: 0.04 mg/mL of isoflupredone acetate in water-saturated chloroform

Standard solution: 33 µg/mL of USP Diflorasone Diacetate RS in the Internal standard solution

Sample solution: 0.03 mg/mL of Diflorasone Diacetate in the Internal standard solution

3.1.1 Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 10-cm; 3-µm packing L3

Flow rate: 2.5 mL/min

Injection volume: 10 µL

3.1.2 System suitability

Sample: Standard solution

[NOTE-The relative retention times for diflorasone diacetate and the internal standard are 1.0 and 2.4, respectively.]

3.1.3 Suitability requirements

Resolution: NLT 12 between the analyte and the internal standard peaks

Relative standard deviation: NMT 2.0% for NLT four replicate injections

3.1.4 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of diflorasone diacetate (C₂₆H₃₂F₂O₇) in the portion of Diflorasone Diacetate taken: 26 32

                Result = (R_U/R_S) x (C_S/C_U) × 100

R_U = peak area ratio of diflorasone diacetate and the internal standard from the Sample solution

R_S = peak area ratio of diflorasone diacetate and the internal standard from the Standard solution S

C_S = concentration of USP Diflorasone Diacetate RS in the Standard solution (µg/mL)

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

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

4 IMPURITIES

4.1 RESIDUE ON IGNITION (281): NMT 0.5%

4.2 ORGANIC IMPURITIES

Mobile phase and System suitability: Proceed as directed in the Assay.

Sample solution: 6 mg/mL of Diflorasone Diacetate in water-saturated chloroform

Chromatographic system: Proceed as directed in the Assay, except for the following.

Run time: 5 times the retention time of the major peak

Analysis

Sample: Sample solution

Calculate the percentage of each impurity in the portion of Diflorasone Diacetate taken:

                Result = (r_U/r_T) × 100

r_U = peak area for each impurity

r_T = sum of all the peak areas

Acceptance criteria

Individual impurities: NMT 1.0%

Total impurities: NMT 2.0%

5 SPECIFIC TESTS

5.1 LOSS ON DRYING (731)

Analysis: Dry under vacuum at 60° at a pressure NMT 5 mm of mercury for 16 h.

Acceptance criteria: NMT 0.5%

5.2 OPTICAL ROTATION, Specific Rotation (781S)

Sample solution: 20 mg/mL of undried Diflorasone Diacetate, in chloroform

Acceptance criteria: +58° to +68°

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight containers.

USP REFERENCE STANDARDS (11)

USP Diflorasone Diacetate RS