Neomycin Sulfate and Fluorometholone Ointment
»Neomycin Sulfate and Fluorometholone Ointment contains the equivalent of not less than 90.0percent and not more than 135.0percent of the labeled amount of neomycin,and not less than 90.0percent and not more than 110.0percent of the labeled amount of fluorometholone (C22H29FO4).
Packaging and storage— Preserve in collapsible tubes or in well-closed containers.
Identification—
A: It meets the requirements for neomycin underThin-Layer Chromatographic Identification Test á201BNPñ.
B: The ratios of the retention time of the main peak to that of the internal standard peak obtained from theStandard preparation and theAssay preparation as directed in theAssay for fluorometholone do not differ by more than 2.0%.
Minimum fill á755ñ: meets the requirements.
Water,Method Iá921ñ: not more than 1.0%,20mLof a mixture of toluene and methanol (7:3)being used in place of methanol in the titration vessel.
Assay for neomycin— Proceed with Ointment as directed in theAssay underNeomycin Sulfate Ointment.
Assay for fluorometholone—
Internal standard solution,Mobile solvent,and Standard preparation— Prepare as directed in theAssay underFluorometholone Cream.
Assay preparation— Transfer an accurately weighed quantity of Ointment,equivalent to about 1mg of fluorometholone,to a suitable container,add 20.0mLofInternal standard solution,and mix.
Procedure— Treat 20.0mLeach of theStandard preparation and theAssay preparation in the following manner.To each add 10.0mLof hexane,shake for about 15minutes,then allow the layers to separate,and centrifuge,if necessary.Using the lower (acetonitrile)layer,proceed as directed forProcedure in theAssay underFluorometholone Cream,beginning with “Using a suitable microsyringe.”Calculate the quantity,in mg,of C22H29FO4in the portion of Ointment taken by the formula:
20C(RU/RS),
in which the terms are as defined therein.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1346
Pharmacopeial Forum:Volume No.28(4)Page 1155
Phone Number:1-301-816-8335
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