Assay
Mobile phase, Standard preparation, Chromatographic system
Proceed as directed in the
Assay under
Rimexolone.
Assay preparation
Transfer an accurately weighed portion of Ophthalmic Suspension, equivalent to about 25 mg of Rimexolone, to a 25-mL volumetric flask, dilute with methanol to volume, and sonicate for 2 minutes. Transfer 5.0 mL of this suspension to a 25-mL volumetric flask, dilute with Mobile phase to volume, mix, and filter.
Procedure
Separately inject equal volumes (about 20 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 rimexolone (C
24H
34O
3) in the portion of Ophthalmic Suspension taken by the formula:
125C(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Rimexolone RS in the
Standard preparation, and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.