Assay
Mobile phase, Solvent, Diluting solution, Standard preparation, System suitability solution and Chromatographic system
Proceed as directed in the
Assay under
Hydrocortisone Butyrate.
Assay preparation
Transfer an accurately weighed quantity of Cream, equivalent to about 1.0 mg of Hydrocortisone Butyrate, to a 50-mL volumetric flask, dissolve in 10 mL of Solvent, shake by mechanical means for 30 minutes, and dilute with Diluting solution to volume.
Procedure
Separately inject equal volumes (about 5 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of hydrocortisone butyrate (C
25H
36O
6) in the portion of Cream taken by the formula:
50C(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Hydrocortisone Butyrate RS in the
Standard preparation; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.