A: Transfer about 100 mg to a separator, dissolve in 10 mL of water, add 1 mL of 3 N hydrochloric acid, and extract immediately with 50 mL of chloroform. Filter the chloroform extract through cotton, evaporate on a steam bath to dryness, and dry in vacuum at 60 for 3 hours: the IR absorption spectrum of a mineral oil dispersion of the residue so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of USP Methylprednisolone Hemisuccinate RS.

B: Ultraviolet Absorption 197U—

C: It responds to the flame test for Sodium 191.

Test solution: 10 mg per mL, in alcohol.

(Official January 1, 2007)

Standard preparation— Proceed as directed under Assay for Steroids 351, using USP Methylprednisolone Hemisuccinate RS to obtain a solution having a known concentration of about 12.5 µg per mL.

Assay preparation— Weigh accurately about 100 mg of Methylprednisolone Sodium Succinate, dissolve it in alcohol to make 200.0 mL, and mix. Pipet 5 mL of this solution into a 200-mL volumetric flask, add alcohol to volume, and mix. Pipet 20 mL of the resulting solution into a glass-stoppered, 50-mL conical flask.

Procedure— To each of the flasks containing the Assay preparation and the Standard preparation, and to a similar flask containing 20.0 mL of alcohol, to provide the blank, add 2.0 mL of a solution prepared by dissolving 50 mg of blue tetrazolium in 10 mL of alcohol, and mix. Then to each flask add 4.0 mL of a mixture of 1 volume of tetramethylammonium hydroxide TS and 9 volumes of alcohol. Mix, allow to stand in the dark for 90 minutes, add 1.0 mL of glacial acetic acid, mix, and proceed as directed for Procedure under Assay for Steroids 351, beginning with “Concomitantly determine the absorbances.” Calculate the quantity, in mg, of C26H33NaO8 in the portion of Methylprednisolone Sodium Succinate taken by the formula: