U.S. PHARMACOPEIA

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Triamcinolone Acetonide Topical Aerosol
» Triamcinolone Acetonide Topical Aerosol is a solution of Triamcinolone Acetonide in a suitable propellant in a pressurized container. It contains not less than 90.0 percent and not more than 115.0 percent of the labeled amount of C24H31FO6.
Packaging and storage— Preserve in pressurized containers, and avoid exposure to excessive heat.
Identification— Apply 20 µL of a solution prepared as directed for Assay preparation in the Assay but without the addition of the Internal standard solution, and 20 µL of a solution of USP Triamcinolone Acetonide RS in methanol containing 30 µg per mL, to a line parallel to and about 1.5 cm from the bottom edge of a thin-layer chromatographic plate (see Chromatography 621) coated with a 0.25-mm layer of chromatographic silica gel. Proceed as directed in the Identification test under Triamcinolone Acetonide Cream, beginning with “Place the plate in a developing chamber.” The specified result is obtained.
Microbial limits 61 It meets the requirements of the tests for absence of Staphylococcus aureus and Pseudomonas aeruginosa.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Other requirements— It meets the requirements for Pressure Test, Minimum Fill, and Leakage Test under Aerosols, Nasal Sprays, Metered-Dose Inhalers, and Dry Powder Inhalers 601.
Assay—
Mobile phase— Prepare a degassed solution of water and acetonitrile (70:30).
Internal standard solution— Dissolve fluoxymesterone in methanol to obtain a solution having a concentration of about 25 µg per mL.
Standard preparation— Dissolve an accurately weighed quantity of USP Triamcinolone Acetonide RS in methanol to obtain a solution having a concentration of about 100 µg per mL. Transfer 15.0 mL of this solution to a 50-mL volumetric flask, add 25.0 mL of Internal standard solution, dilute with methanol to volume, and mix. This solution has a known concentration of about 30 µg per mL.
Assay preparation— Fit the valve of a previously weighed Triamcinolone Acetonide Aerosol container with a suitable tube assembly so that the contents can be sprayed directly into the bulb portion of a 100-mL volumetric flask containing 50.0 mL of Internal standard solution and 20 mL of methanol. Spray a portion of the contents, equivalent to about 3 mg of triamcinolone acetonide, into the flask, determining the exact amount sprayed by difference. Place in a sonic bath for about 5 minutes to expel the propellant. Dilute with methanol to volume, and mix. [NOTE—The propellant is extremely flammable. When evaporating, observe proper precautions and work under an explosion-proof hood.]
Procedure— Introduce equal volumes (between 15 µL and 25 µL) of the Assay preparation and the Standard preparation into a chromatograph (see Chromatography 621) operated at room temperature and fitted with a 3.9-mm × 30-cm column, packed with packing L1, and equipped with a 254-nm detector. Adjust the operating parameters and the Mobile phase composition such that the separation of triamcinolone acetonide and internal standard is optimized, with a retention time of about 14 minutes for triamcinolone acetonide. In a suitable system, the relative standard deviation for five replicate injections of the Standard preparation is not more than 3.0%. Measure the responses of the internal standard and triamcinolone acetonide peaks at the same retention times obtained from the Assay preparation and the Standard preparation. Calculate the quantity, in µg, of C24H31FO6 in the portion of Topical Aerosol taken by the formula:
100C(RU / RS),
in which C is the concentration, in µg per mL, of USP Triamcinolone Acetonide RS in the Standard preparation, and RU and RS are the ratios of the peak responses of triamcinolone acetonide to internal standard obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Staff Liaison : Daniel K. Bempong, Ph.D., Scientist
Expert Committee : (MDPS05) Monograph Development-Pulmonary and Steroids
USP29–NF24 Page 2184
Phone Number : 1-301-816-8143