Neomycin and Polymyxin B Sulfates, Bacitracin Zinc, and Hydrocortisone Ophthalmic Ointment
» Neomycin and Polymyxin B Sulfates, Bacitracin Zinc, and Hydrocortisone Ophthalmic Ointment is a sterile ointment containing Neomycin Sulfate, Polymyxin B Sulfate, Bacitracin Zinc, and Hydrocortisone. It contains the equivalent of not less than 90.0 percent and not more than 140.0 percent of the labeled amounts of neomycin, polymyxin B, and bacitracin, and not less than 90.0 percent and not more than 110.0 percent of the labeled amount of hydrocortisone.
Packaging and storage— Preserve in collapsible ophthalmic ointment tubes.
A: It meets the requirements under Thin-Layer Chromatographic Identification Test 201BNP.
B: The retention time of the major peak for hydrocortisone in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay for hydrocortisone.
Sterility 71: meets the requirements.
Minimum fill 755: meets the requirements.
Water, Method I 921: not more than 0.5%, 20 mL of 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 for Metal Particles in Ophthalmic Ointments 751.
Assay for neomycin, Assay for polymyxin B, and Assay for bacitracin— Proceed as directed in the Assay for neomycin, the Assay for polymyxin B, and the Assay for bacitracin under Neomycin and Polymyxin B Sulfates and Bacitracin Zinc Ophthalmic Ointment.
Assay for hydrocortisone—
Mobile phase— Prepare a suitable solution of about 500 volumes of methanol, 500 volumes of water, and 1 volume of glacial acetic acid, such that the retention time of hydrocortisone is between 6 and 10 minutes.
Standard preparation— Dissolve a suitable quantity of USP Hydrocortisone RS, accurately weighed, in methanol and water (1:1) to obtain a solution having a known concentration of about 0.15 mg per mL.
Assay preparation— Transfer to a separator about 1.5 g, accurately weighed, of Ophthalmic Ointment. Add 3 mL of n-hexane, and warm gently on a steam bath with mild agitation until dissolved. Add 7 mL of n-hexane, mix by swirling, and extract with four 15-mL portions of methanol and water (1:1). Collect the extracts in a 100-mL volumetric flask, dilute with methanol and water (1:1) to volume, and mix. Filter the solution, rejecting the first 10 mL of the filtrate.
Chromatographic system (see Chromatography 621)— The chromatograph is equipped with a 254-nm detector and a 4-mm × 30-cm column that contains packing L1. The flow rate is about 2 mL per minute. Chromatograph five replicate injections of the Standard preparation and record the peak responses as directed under Procedure: the relative standard deviation is not more than 2.0%.
Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph by means of a suitable microsyringe or sampling valve, adjusting the specimen size and other operating parameters such that the peak obtained from the Standard preparation is about 0.6 full-scale. Record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg per g, of C21H30O5 in the Ophthalmic Ointment taken by the formula:
(100C/W)(rU / rS)
in which C is the concentration, in mg per mL, of USP Hydrocortisone RS in the Standard preparation; W is the weight, in g, of the portion of Ophthalmic Ointment taken; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ahalya Wise, M.S.
(MDANT05) Monograph Development-Antibiotics
Reference Standards Lili Wang, Technical Services Scientist
71 Radhakrishna S Tirumalai, Ph.D.
Senior Scientist
(MSA05) Microbiology and Sterility Assurance
USP32–NF27 Page 3059
Pharmacopeial Forum: Volume No. 28(4) Page 1162
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.