Amcinonide Cream
»Amcinonide Cream is Amcinonide in a suitable cream base.It contains not less than 90.0percent and not more than 115.0percent of the labeled amount of amcinonide (C28H35FO7).
Packaging and storage— Preserve in tight containers.
Identification— Place 2g of the Cream in a 150-mLbeaker,add 50mLof chloroform and 15g of anhydrous sodium sulfate,and stir with a glass rod to dissolve the specimen.Filter the solution,and clarify the filtrate,if necessary,by the further addition of anhydrous sodium sulfate and a second filtration.Evaporate the filtrate to dryness,and dissolve the residue in chloroform to obtain a solution containing about 100µg of amcinonide per mL.Apply 25µLof this solution,and 25µLof a solution of USP Amcinonide RSin chloroform containing 100µg per mL,on a line parallel to and about 3cm from the bottom edge of a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel.Place the plate in a developing chamber containing and equilibrated with ether.Develop the chromatogram until the solvent front has moved about 12cm above the line of application.Remove the plate,allow the solvent to evaporate,and locate the spots on the plate by viewing under short-wavelength UVlight:the intensity and the RFvalue of the principal spot obtained from the solution under test are similar to those of the spot 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.
pHá791ñ: between 3.5and 5.2.
Assay—
Solution A,Solution B,Mobile phase,System suitability solution,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Amcinonide.
Assay preparation— Transfer an accurately weighed quantity of Cream,equivalent to about 10mg of Amcinonide,to a 50-mLvolumetric flask,add 5mLof Solution Band 15mLof acetonitrile,and heat over a steam bath until dissolved.Add 20mLof Solution Bwhile hot,cool to room temperature,dilute with Solution Bto volume,and refrigerate for 30minutes.Vigorously shake the solution to disperse the mixture,and filter while cold.Transfer 5mLof this solution to a 50-mLvolumetric flask,dilute with Solution Bto volume,and mix.
Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparation.Record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of amcinonide (C28H35FO7)in the portion of Cream taken by the formula:
500C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Amcinonide RSin the Standard preparation;and rUand rSare the peak responses 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 113
Phone Number:1-301-816-8139