Neomycin Sulfate and Dexamethasone Sodium Phosphate Ophthalmic Ointment
»Neomycin Sulfate and Dexamethasone Sodium Phosphate Ophthalmic Ointment is a sterile ointment containing Neomycin Sulfate and Dexamethasone Sodium Phosphate.It contains the equivalent of not less than 90.0percent and not more than 135.0percent of the labeled amount of neomycin,and the equivalent of not less than 90.0percent and not more than 110.0percent of the labeled amount of dexamethasone phosphate (C22H30FO8P).
NOTE—Where Neomycin Sulfate and Dexamethasone Sodium Phosphate Ophthalmic Ointment is prescribed without reference to the quantity of neomycin or dexamethasone phosphate contained therein,a product containing 3.5mg of neomycin and 0.5mg of dexamethasone phosphate per g shall be dispensed.
Packaging and storage— Preserve in collapsible ophthalmic ointment tubes.
Identification—
A: It meets the requirements for neomycin underThin-Layer Chromatographic Identification Test á201BNPñ.
B: TheAssay preparation,prepared as directed in theAssay for dexamethasone phosphate,meets the requirements for theIdentification test underDexamethasone Sodium Phosphate Cream.
Sterility á71ñ: meets the requirements.
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.
Metal particles— It meets the requirements of the test forMetal Particles in Ophthalmic Ointments á751ñ.
Assay for neomycin— Proceed as directed underAntibiotics—Microbial Assays á81ñ,using an accurately weighed portion of Ophthalmic Ointment shaken in a separator with about 50mLof ether,and extracted with four 20-mLportions ofBuffer No.3.Combine the aqueous extracts,and dilute withBuffer No.3to an appropriate volume to obtain a stock solution.Dilute this stock solution quantitatively and stepwise withBuffer No.3to obtain aTest Dilution having a concentration assumed to be equal to the median dose level of the Standard.
Assay for dexamethasone phosphate—
Alcohol–aqueous phosphate buffer,0.05M Phosphate buffer,Mobile phase,Standard preparation,and Chromatographic system— Prepare as directed in theAssay underDexamethasone Sodium Phosphate Cream.
Assay preparation— Using an accurately weighed portion of Ophthalmic Ointment,prepare as directed in theAssay underDexamethasone Sodium Phosphate Cream.
Procedure— Proceed as directed forProcedure in theAssay underDexamethasone Sodium Phosphate Cream.Calculate the quantity,in mg,of dexamethasone phosphate (C22H30FO8P)in the portion of Ophthalmic Ointment taken by the formula:
0.1C(rU/rS).
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1345
Pharmacopeial Forum:Volume No.28(4)Page 1154
Phone Number:1-301-816-8335
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