Neomycin Sulfate,Sulfacetamide Sodium,and Prednisolone Acetate Ophthalmic Ointment
»Neomycin Sulfate,Sulfacetamide Sodium,and Prednisolone Acetate Ophthalmic 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 amounts of sulfacetamide sodium (C8H9N2NaO3S·H2O)and prednisolone acetate (C23H30O6).
Packaging and storage—
Preserve in collapsible ophthalmic ointment tubes.
Identification—
A:
Dissolve a quantity of Ophthalmic Ointment,equivalent to about 1g of sulfacetamide sodium,in 100mLof ether in a separator,and extract the mixture with 25mLof water.Wash the extract with 25mLof ether,and warm the water extract on a steam bath to remove the last traces of ether.Adjust with 6Nacetic acid to a pHof between 4and 5,and filter.Wash the precipitate with water,and dry at 105
for 2hours:the sulfacetamide so obtained melts between 180and 184,and responds to Identificationtests B,D,and Eunder Sulfacetamide Sodium.
for 2hours:the sulfacetamide so obtained melts between 180and 184,and responds to Identificationtests B,D,and Eunder Sulfacetamide Sodium.
B:
To a quantity of Ophthalmic Ointment,equivalent to about 25mg of prednisolone acetate,add 15mLof water,extract with two 10-mLportions of peroxide-free ether,discard the ether extracts,and extract with two 10-mLportions of chloroform.Evaporate the combined,clear chloroform extracts,with the aid of a current of air,to dryness:the residue so obtained responds to Identificationtest Aunder Prednisolone Acetate.
Sterility á71ñ—
It meets the requirements when tested as directed for Membrane Filtrationunder Test for Sterility of the Product to be Examined.
Minimum fill á755ñ:
meets the requirements.
Metal particles—
It meets the requirements of the test for Metal Particles in Ophthalmic Ointments á751ñ.
Assay for neomycin—
Proceed with Ophthalmic Ointment as directed in the Assayunder Neomycin Sulfate Ointment.
Assay for sulfacetamide sodium—
Weigh accurately a quantity of Ophthalmic Ointment,equivalent to about 500mg of sulfacetamide sodium,and transfer to a 125-mLseparator.Dissolve the ointment in 50mLof ether,and extract the mixture with six 25-mLportions of water.Warm the combined extracts on a steam bath to remove the last traces of ether,add 20mLof hydrochloric acid,and proceed as directed under Nitrite Titration á451ñ,beginning with “cool to 15.”Each mLof 0.1Msodium nitrite is equivalent to 25.42mg of C8H9N2NaO3S·H2O.
.”Each mLof 0.1Msodium nitrite is equivalent to 25.42mg of C8H9N2NaO3S·H2O.
Assay for prednisolone acetate—
Standard preparation—
Prepare as directed for Standard Preparationunder Assay for Steroids á351ñ,using USP Prednisolone Acetate RS.
Assay preparation—
Transfer to a suitable flask an accurately weighed quantity of Ophthalmic Ointment,equivalent to about 10mg of prednisolone acetate,and add 30mLof alcohol.Heat on a steam bath to melt the ointment base,and mix.Cool to solidify the ointment base,and filter the alcohol solution into a 100-mLvolumetric flask.Repeat the extraction with three 20-mLportions of alcohol,add alcohol to volume,and mix.Pipet 10mLof this solution into a 100-mLvolumetric flask,add alcohol to volume,and mix.Pipet 20mLof the resulting solution into a glass-stoppered,50-mLconical flask.
Procedure—
Proceed as directed for Procedureunder Assay for Steroids á351ñ.Calculate the quantity,in mg,of C23H30O6in the portion of Ophthalmic Ointment taken by the formula:
C(AU/AS).
Auxiliary Information—
Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1363
Phone Number:1-301-816-8335