Fluocinonide Cream
»Fluocinonide Cream contains not less than 90.0percent and not more than 110.0percent of the labeled amount of fluocinonide (C26H32F2O7).
Packaging and storage— Preserve in collapsible tubes or tight containers.
Identification— Weigh an amount of Cream,equivalent to about 2.5mg of fluocinonide,into a glass-stoppered,100-mLcentrifuge tube containing 5mLof water and 10mLof methanol.Add 20mLof cyclohexane,shake vigorously,centrifuge,and discard the upper phase.Add 20mLof water and 5mLof chloroform,shake vigorously,centrifuge until the lower phase is clear,and discard the upper phase.The clear chloroform extract is the Test solution.Separately apply 10µLof the Test solutionand 10µLof a Standard solution having a concentration of 0.5mg per mLof USP Fluocinonide RSin chloroform to equidistant points about 2cm from one end of a thin-layer chromatographic plate (see Chromatography á621ñ),coated with a 0.25-mm layer of chromatographic silica gel.Allow the applications to dry,and develop the chromatogram in a suitable chromatographic chamber using a mixture of chloroform and acetone (4:1).Air-dry,and view under short-wavelength UVlight:the principal spot from the Test solutioncorresponds to that obtained from the Standard solution.
Microbial limits á61ñ— It meets the requirements of the tests for absence of Staphylococcus aureusand Pseudomonas aeruginosa.
Minimum fill á755ñ: meets the requirements.
Assay—
Mobile phase— Prepare a filtered and degassed mixture of acetonitrile and water (1:1).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Standard preparation— Dissolve an accurately weighed quantity of USP Fluocinonide RSin acetonitrile to obtain a solution having a known concentration of about 200µg per mL.Transfer 10.0mLof this solution and 10.0mLof water to a 100-mLvolumetric flask.Dilute with acetonitrile to volume,and mix.The final concentration of USP Fluocinonide RSis 20µg per mL.
Assay preparation— Transfer an accurately weighed quantity of Cream,containing about 2mg of fluocinonide,to a 100-mLvolumetric flask.Add about 60mLof acetonitrile,and dissolve the cream by heating on a steam bath.Add 10.0mLof water,and allow to cool.Dilute with acetonitrile to volume,and mix.Filter the mixture through a fine-sintered glass funnel,using vacuum,and use the filtrate.
Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm ×30-cm column that contains packing L1.The flow rate is about 2mLper minute.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the column efficiency is not less than 4500theoretical plates and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— Chromatograph equal volumes (about 20µL)of the Assay preparationand the Standard preparation,record the chromatograms,and measure the peak responses due to fluocinonide.Calculate the quantity,in mg,of fluocinonide (C26H32F2O7)in the portion of Cream taken by the formula:
0.1C(rU/rS),
in which Cis the concentration,in µg per mL,of USP Fluocinonide RSin the Standard preparation,and rUand rSare the peak responses due to fluocinonide obtained from the Assay preparationand the Standard preparation;respectively.
Auxiliary Information— Staff Liaison:Clydewyn M.Anthony,Ph.D.,Scientist
Expert Committee:(PA1)Pharmaceutical Analysis 1
USP28–NF23Page 841
Phone Number:1-301-816-8139