Natamycin Ophthalmic Suspension
»Natamycin Ophthalmic Suspension is a sterile suspension of Natamycin in a suitable aqueous vehicle.It contains not less than 90.0percent and not more than 125.0percent of the labeled amount of C33H47NO13.It contains one or more suitable preservatives.
Packaging and storage— Preserve in tight,light-resistant containers.The containers or individual cartons are sealed and tamper-proof so that sterility is assured at time of first use.
Identification— Transfer a volume of Ophthalmic Suspension,equivalent to about 50mg of natamycin,to a 200-mLvolumetric flask,and add water to make a volume of 5mL.Proceed as directed in the Identificationtest under Natamycin,beginning with “Add 100mLof a 1in 1000solution of glacial acetic acid in methanol:”the specified result is obtained.
Sterility á71ñ— It meets the requirements as directed for Direct Inoculation of the Culture Mediumunder Test for Sterility of the Product to be Examined,using 0.25mLof the Ophthalmic Suspension taken from each container.
pHá791ñ: between 5.0and 7.5.
Assay— [NOTE—Throughout the Assay protect from direct light all solutions containing natamycin.]
Mobile phase ,Standard preparation,Resolution solution,and Chromatographic system—Proceed as directed in the Assayunder Natamycin.
Assay preparation— Transfer an accurately measured volume of Ophthalmic Suspension,equivalent to about 50mg of natamycin,to a 250-mLvolumetric flask.Add 12.5mLof tetrahydrofuran,and sonicate for 10minutes.Add 150mLof methanol,and swirl to dissolve.Add 60mLof water,and mix.Allow to cool to room temperature.Dilute with water to volume,and mix.Filter this solution through a suitable membrane filter of 0.5-µm or finer porosity.
Procedure— Proceed as directed in the Assayunder Natamycin.Calculate the quantity,in mg,of C33H47NO13in each mLof the Ophthalmic Suspension taken by the formula:
0.25C(PS/V)(rU/rS),
in which Cis the concentration,in mg per mL,of USP Natamycin RSin the Standard preparation,PSis the stated content,in µg per mg,of USP Natamycin RS,Vis the volume,in mL,of Ophthalmic Suspension taken,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1342
Phone Number:1-301-816-8335