Identification
Extract a volume of Injectable Suspension,equivalent to about 50mg of triamcinolone acetonide,with two 10-mLportions of peroxide-free ether,and discard the ether extracts.Filter with the aid of suction,wash with small portions of water,and dry the precipitate at 105

for 1hour:the triamcinolone acetonide so obtained responds to the
Identificationtests under
Triamcinolone Acetonide.
Assay
Mobile phase:
approximately 30%acetonitrile in water.
Internal standard solution
Dissolve fluoxymesterone in methanol to obtain a solution having a concentration of about 84µg per mL.
Standard preparation
Dissolve an accurately weighed quantity of
USP Triamcinolone Acetonide RSin methanol to obtain a solution having a known concentration of about 200µg per mL.Pipet 20mLof this solution into a 50-mLvolumetric flask,dilute with
Internal standard solutionto volume,and mix.The
Standard preparationhas a known concentration of about 80µg of
USP Triamcinolone Acetonide RSper mL.
Assay preparation
Dissolve an accurately measured volume of freshly mixed Injectable Suspension in methanol,and dilute quantitatively with methanol to obtain a solution having an expected concentration of about 200µg of triamcinolone acetonide per mL.Pipet 20mLof this solution into a 50-mLvolumetric flask,dilute with Internal standard solutionto volume,and mix.
Procedure
Proceed as directed for
Procedurein the
Assayunder
Triamcinolone Acetonide Cream,except to use peak responses in the calculation.Calculate the quantity,in mg,of C
24H
31FO
6in each mLof the Injectable Suspension taken by the formula:
(CD/V)(RU/RS),
in which
Cis the concentration,in mg per mL,of
USP Triamcinolone Acetonide RSin the
Standard preparation,
Dis the dilution factor used in the
Assay preparation,
Vis the volume,in mL,of Injectable Suspension taken,and
RUand
RSare the ratios of the peak responses of triamcinolone acetonide to the internal standard,obtained from the
Assay preparationand the
Standard preparation,respectively.