Fluocinonide Cream

BP 2025 (Ph. Eur. 11.6 update)

Action and use

Glucocorticoid.

DEFINITION

Fluocinonide Cream contains Fluocinonide in a suitable basis.

The cream complies with the requirements stated under Topical Semi-solid Preparations and with the following requirements.

Content of fluocinonide, C₂₆H₃₂F₂O₇

90.0 to 110.0% of the stated amount.

IDENTIFICATION

A. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.

1. Disperse a quantity of the cream containing 2.5 mg of Fluocinonide in 25 mL of methanol (80%), add 50 mL of ether and shake vigorously to produce a clear, homogeneous solution. Add 15 mL of water, shake and transfer the lower layer to a second separating funnel. Add 100 mL of water, extract with 10 mL of chloroform, filter the chloroform layer through filter paper and evaporate to a volume of about 1 mL in a current of air on a water bath.
2. 0.1% w/v of fluocinonide BPCRS in a mixture of 1 volume of methanol and 9 volumes of dichloromethane.

CHROMATOGRAPHIC CONDITIONS

1. Use as the coating silica gel F₂₅₄.
2. Use the mobile phase as described below.
3. Apply 10 μL of each solution.
4. Develop the plate to 15 cm.
5. After removal of the plate, dry in air and examine under ultraviolet light (254 nm).

MOBILE PHASE

12 volumes of water, 80 volumes of methanol, 150 volumes of ether and 770 volumes of dichloromethane. Mix the water and the methanol before adding to the remaining solvents of the mobile phase.

CONFIRMATION

The principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).

B. In the Assay, the retention time of the principal peak in the chromatogram obtained with solution (1) is similar to that of the principal peak in the chromatogram obtained with solution (2).

ASSAY

Carry out the method for liquid chromatography, Appendix III D, using the following solutions.

1. Disperse a quantity of the cream containing 1.5 mg of Fluocinonide in 20 mL of methanol (80%), warming gently over a water bath if necessary. Add 50 mL of 2,2,4-trimethylpentane, shake for 2 minutes and transfer the lower aqueous methanol layer to a 50-mL flask. Repeat the extraction with a further 20 mL of methanol (80%). Dilute the combined extracts to volume with the same solvent.
2. 0.003% w/v of fluocinonide BPCRS in methanol (80%).

CHROMATOGRAPHIC CONDITIONS

1. Use a stainless steel column (20 cm x 4.6 mm) packed with octadecylsilyl silica gel for chromatography (5 μm) (Spherisorb ODS 1 is suitable).
2. Use isocratic elution and the mobile phase described below.
3. Use a flow rate of 2 mL per minute.
4. Use an ambient column temperature.
5. Use a detection wavelength of 238 nm.
6. Inject 20 μL of each solution.

MOBILE PHASE

0.1 volume of glacial acetic acid, 45 volumes of acetonitrile and 55 volumes of water.

DETERMINATION OF CONTENT

Calculate the content of C₂₆H₃₂F₂O₇ in the cream using the declared content of C₂₆H₃₂F₂O₇ in fluocinonide BPCRS.