Identification—
Extract a volume of Injectable Suspension, equivalent to about 50 mg of triamcinolone acetonide, with two 10-mL portions 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 1 hour: the triamcinolone acetonide so obtained responds to the
Identification tests 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 84 µg per 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 200 µg of triamcinolone acetonide per mL. Pipet 20 mL of this solution into a 50-mL volumetric flask, dilute with
Internal standard solution to volume, and mix.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Triamcinolone Acetonide Cream, except to use peak responses in the calculation. Calculate the quantity, in mg, of C
24H
31FO
6 in each mL of the Injectable Suspension taken by the formula:
(CD / V)(RU / RS),
in which
C is the concentration, in mg per mL, of
USP Triamcinolone Acetonide RS in the
Standard preparation,
D is the dilution factor used in the
Assay preparation,
V is the volume, in mL, of Injectable Suspension taken, and
RU and
RS are the ratios of the peak responses of triamcinolone acetonide to the internal standard, obtained from the
Assay preparation and the
Standard preparation, respectively.
85
—
It contains not more than 4.4 USP Endotoxin Units per mg of triamcinolone acetonide.