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Fluocinolone Acetonide Ointment
» Fluocinolone Acetonide Ointment contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C24H30F2O6.
Packaging and storage
Preserve in collapsible tubes or tight containers.
Identification
Evaporate 10.0 mL of the Assay preparation obtained in the Assay to dryness, and dissolve the residue in 1 mL of chloroform: it responds to the Thin-layer Chromatographic Identification Test
Microbial enumeration tests
Minimum fill
Assay
Internal standard solution
Dissolve a suitable quantity of USP Norethindrone RS in methanol to obtain a solution containing about 850 µg per mL.
Diluted internal standard solution
Transfer 5.0 mL of Internal standard solution to a 250-mL flask. Dilute with methanol to volume, and mix.
Standard preparation
Dissolve an accurately weighed quantity of USP Fluocinolone Acetonide RS in acetonitrile to obtain a solution having a known concentration of about 200 µg per mL. Transfer 10.0 mL of this solution and 2.0 mL of Internal standard solution to a 100-mL volumetric flask. Dilute with methanol to volume, and mix. The concentration of USP Fluocinolone Acetonide RS in the Standard preparation is 20 µg per mL.
Mobile solvent
Prepare a mixture of acetonitrile and water (1:1). Adjust the ratio as necessary to obtain suitable chromatographic performance.
Assay preparation
Transfer an accurately weighed portion of Ointment, equivalent to about 0.7 mg of fluocinolone acetonide, to a 50-mL, round-bottom centrifuge tube. Add 35.0 mL of Diluted internal standard solution, emulsify using an ultrasonic probe, and centrifuge to bring the insoluble matter to the bottom. The clear supernatant is the Assay preparation.
Apparatus
Use a suitable high-pressure liquid chromatograph (see Chromatography
Procedure
Chromatograph equal volumes of the Assay preparation and the Standard preparation, adjusting the system as necessary to obtain peaks of between about 50% and 90% of full-scale. Calculate the quantity, in mg, of C24H30F2O6 in the portion of Ointment taken by the formula:
0.035C(RU / RS)
in which C is the concentration, in µg per mL, of USP Fluocinolone Acetonide RS in the Standard preparation; and RU and RS are the ratios of the peak areas of fluocinolone acetonide and the internal standard obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3226
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