Assay
Assay preparation
Transfer to a suitable flask an accurately weighed quantity of Ophthalmic Ointment, equivalent to about 10 mg of hydrocortisone acetate, and add 30 mL of alcohol. Heat on a steam bath to melt the ointment base, and mix. Cool to solidify the ointment base, and filter the alcohol solution into a 100-mL volumetric flask. Repeat the extraction with three 20-mL portions of alcohol, add alcohol to volume, and mix. Pipet 10 mL of this solution into a 100-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
Proceed as directed for
Procedure under
Assay for Steroids 351. Calculate the quantity, in mg, of C
23H
32O
6 in the portion of Ophthalmic Ointment taken by the formula:
C(AU / AS),
in which the terms are as defined therein.