Packaging and storage— Preserve in well-closed containers.

USP Reference standards á11ñ— USP Triamcinolone Acetonide RS.

Identification— Place 2g of Ointment in a conical flask,add 5.0mLof chloroform,and shake for 10minutes.Add 15mLof alcohol,and shake for an additional 10minutes.Filter the solution into a centrifuge tube,and evaporate the filtrate to dryness.Dissolve the residue in alcohol to obtain a solution containing about 250µg per mL.Apply 10µLof this solution,and 10µLof a solution of USP Triamcinolone Acetonide RSin alcohol containing 250µg per mL,on a line parallel to and about 1.5cm 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 a mixture of chloroform,benzene,and methanol (100:40:20).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 spray with a mixture of equal volumes of sodium hydroxide solution (1in 5)and a 1in 500solution of blue tetrazolium in methanol:the intensity of the blue color and the RFof the 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.

Assay— Proceed with Ointment as directed in the Assayunder Triamcinolone Acetonide Cream,except to read “Ointment”in place of “Cream”throughout.

Expert Committee:(PA1)Pharmaceutical Analysis 1

USP28–NF23Page 1961

Phone Number:1-301-816-8139