Identification—
Transfer a quantity of Oral Solution,equivalent to about 10mg of triamcinolone diacetate,to a separator,and extract with three 10-mLportions of chloroform.Evaporate the combined chloroform extracts on a steam bath to dryness,and dissolve the residue in 5.0mLof chloroform.Apply 10µLeach of this solution and a solution of
USP Triamcinolone Diacetate RSin chloroform containing 2mg per mLto a suitable thin-layer chromatographic plate (see
Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel.Allow the spots to dry,and develop the chromatogram in a solvent system consisting of a mixture of ethyl acetate and chloroform (9:1)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the developing chamber,mark the solvent front,and allow the solvent to evaporate.Locate the spots on the plate by lightly spraying with dilute sulfuric acid (1in 2)and heating on a hot plate or under a lamp until spots appear:the
RFvalue of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.
Assay—
0.005M Monobasic sodium phosphate solution,Mobile phase,Standard preparation,System suitability preparation,andChromatographic system—
Proceed as directed in the
Assayunder
Triamcinolone Diacetate.
Assay preparation—
Quantitatively transfer an accurately measured portion of Oral Solution,equivalent to about 50mg of triamcinolone diacetate to a 100-mLvolumetric flask.Dilute with Mobile phaseto volume,and mix.Pipet 4mLof this solution into a 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Transfer about 25mLof this solution to a 50-mL,glass-stoppered centrifuge tube,and centrifuge at high speed for 10minutes.
Procedure—
Proceed as directed for
Procedurein the
Assayunder
Triamcinolone Diacetate.Calculate the quantity,in mg,of triamcinolone diacetate (C
25H
31FO
8)in the portion of Oral Solution taken by the formula:
1.25C(rU/rS),
in which
Cis the concentration,in µg per mL,of
USP Triamcinolone Diacetate RSin the
Standard preparation;and
rUand
rSare the peak responses obtained from the
Assay preparationand the
Standard preparation,respectively.