Chloramphenicol,Polymyxin B Sulfate,and Hydrocortisone Acetate Ophthalmic Ointment
»Chloramphenicol,Polymyxin B Sulfate,and Hydrocortisone Acetate Ophthalmic Ointment contains not less than 90.0percent and not more than 120.0percent of the labeled amount of chloramphenicol (C11H12Cl2N2O5),not less than 90.0percent and not more than 125.0percent of the labeled amount of polymyxin B,and not less than 90.0percent and not more than 115.0percent of the labeled amount of hydrocortisone acetate (C23H32O6).
Packaging and storage— Preserve in collapsible ophthalmic ointment tubes.
Identification— The retention times of the major peaks in the chromatogram of the Assay preparationcorrespond to those in the chromatogram of the Standard preparationas obtained in the Assay for chloramphenicol and hydrocortisone acetate.
Sterility á71ñ: meets the requirements.
Minimum fill á755ñ: meets the requirements.
Metal particles— It meets the requirements under Metal Particles in Ophthalmic Ointments á751ñ.
Assay for polymyxin— Proceed with Ophthalmic Ointment as directed for polymyxin under Antibiotics—Microbial Assays á81ñ,using an accurately weighed portion of Ophthalmic Ointment,equivalent to about 5000Polymyxin B Units,shaken in a separator containing about 50mLof ether and extracted with four 20-mLportions of Buffer No.6.Combine the aqueous extracts in a 100-mLvolumetric flask,dilute,if necessary,with Buffer No.6to volume,and mix.Dilute an accurately measured portion of the resulting solution quantitatively with Buffer No.6to obtain a Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.
Assay for chloramphenicol and hydrocortisone acetate—
Mobile phase and Chromatographic system—Proceed as directed in the Assayunder Chloramphenicol.
Standard preparation— Transfer about 25mg of USP Chloramphenicol RSand 25Jmg of USP Hydrocortisone Acetate RS,both accurately weighed,Jbeing the ratio of the labeled amount,in mg,of hydrocortisone acetate to the labeled amount,in mg,of chloramphenicol per g of Ophthalmic Ointment,to a 100-mLvolumetric flask,dissolve in methanol,dilute with methanol to volume,and mix.Transfer 10.0mLof the resulting solution to a 25-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Filter a portion of this solution through a 0.5-µm or finer porosity filter,and use the clear filtrate as the Standard preparation.
Assay preparation— Using Ophthalmic Ointment,proceed as directed for Assay preparationin the Assayunder Chloramphenicol Ophthalmic Ointment.
Procedure— Proceed as directed for Procedurein the Assayunder Chloramphenicol.Calculate the quantity,in mg,of chloramphenicol (C11H12Cl2N2O5)in the portion of Ophthalmic Ointment taken by the formula:
0.25C(rU/rS),
in which the terms are as defined therein.Calculate the quantity,in mg,of hydrocortisone acetate (C23H32O6)in the portion of Ophthalmic Ointment taken by the formula:
250C(rU/rS),
in which Cis the concentration,in mg per mL,of USP Hydrocortisone Acetate RSin the Standard preparation,and the other terms are as defined therein.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 431
Phone Number:1-301-816-8335
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