Fluorometholone Ophthalmic Suspension
»Fluorometholone Ophthalmic Suspension is a sterile suspension of Fluorometholone in a suitable aqueous medium.It contains not less than 90.0percent and not more than 110.0percent of the labeled amount of fluorometholone (C22H29FO4).It may contain suitable stabilizers,buffers,and antimicrobial agents.
Packaging and storage—
Preserve in tight containers.
Identification—
Mix 1mLof the well-shaken Ophthalmic Suspension with 2mLof a mixture of methanol and water (3:2)until a solution is obtained.Apply 20-µLportions of this solution and of a Standard solution of USP Fluorometholone RSin the same solvent containing 500µg per mLto a suitable thin-layer chromatographic plate (see Chromatography á621ñ),coated with a 0.25-mm layer of chromatographic silica gel mixture and previously activated by heating at 80
for 5minutes.Allow the spots to dry,and develop the chromatogram in a solvent system consisting of methylene chloride and acetone (4:1)until the solvent front has moved not less than 15cm.Remove the plate from the developing chamber,mark the solvent front,and allow to air-dry.Examine the plate under short-wavelength UVlight:the RFvalue and intensity of the principal spot obtained from the test solution correspond to those obtained from the Standard solution.
for 5minutes.Allow the spots to dry,and develop the chromatogram in a solvent system consisting of methylene chloride and acetone (4:1)until the solvent front has moved not less than 15cm.Remove the plate from the developing chamber,mark the solvent front,and allow to air-dry.Examine the plate under short-wavelength UVlight:the RFvalue and intensity of the principal spot obtained from the test solution correspond to those obtained from the Standard solution.
Sterility á71ñ:
meets the requirements.
pHá791ñ:
between 6.0and 7.5.
Assay—
Mobile phase—
Prepare a suitable filtered solution of methanol and water (60:40)such that the retention time of fluorometholone is about 3minutes.
Standard preparation—
Using a suitable quantity of USP Fluorometholone RS,accurately weighed,prepare a solution in methanol containing 0.5mg per mL.Pipet 10mLof this solution and 5mLof water into a 50-mLvolumetric flask.Dilute with methanol to volume,and mix to obtain a Standard preparationhaving a known concentration of about 100µg per mL.
Assay preparation—
Pipet a volume of well-shaken Ophthalmic Suspension,equivalent to about 5mg of fluorometholone,into a 50-mLvolumetric flask,dilute with methanol to volume,and mix.Pass through a 5-µm membrane filter,and use the clear filtrate.
Chromatographic system
(see Chromatography á621ñ)—The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm ×25-cm column that contains packing L1.The flow rate is about 2mLper minute.Chromatograph six replicate injections of the Standard preparation,and record the peak responses as directed for Procedure:the relative standard deviation is not more than 2.0%.
Procedure—
Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,using a suitable microsyringe or sampling valve,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of fluorometholone (C22H29FO4)in the portion of Ophthalmic Suspension taken by the formula:
0.05C(rU/rS),
in which Cis the concentration,in µg per mL,of USP Fluorometholone RSin the Standard preparation;and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information—
Staff Liaison:Clydewyn M.Anthony,Ph.D.,Scientist
Expert Committee:(PA1)Pharmaceutical Analysis 1
USP28–NF23Page 850
Phone Number:1-301-816-8139