Neomycin and Polymyxin B Sulfates and Hydrocortisone Otic Suspension

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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Neomycin and Polymyxin B Sulfates and Hydrocortisone Otic Suspension is a sterile suspension containing the equivalent of not less than 90.0 percent and not more than 130.0 percent of the labeled amounts of neomycin and of polymyxin B. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of hydrocortisone. It may contain one or more suitable buffers, dispersants, and 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.

USP REFERENCE STANDARDS (11)-

USP Hydrocortisone RS

USP Neomycin Sulfate RS

USP Polymyxin 8 Sulfate RS

THIN-LAYER CHROMATOGRAPHIC IDENTIFICATION TEST (201BNP): meets the requirements.

STERILITY TESTS (71): meets the requirements.

PH (791): between 3.0 and 7.0.

Assay for neomycin and Assay for polymyxin B-Using an accurately measured volume of Otic Suspension, freshly mixed and free from air bubbles, proceed as directed in the Assay for neomycin and the Assay for polymyxin B under Neomycin and Polymyxin B Sulfates and Hydrocortisone Otic Solution.

Assay for hydrocortisone-

Mobile phase, Standard preparation, and Chromatographic system-Prepare as directed in the Assay for hydrocortisone under Neomycin and Polymyxin B Sulfates, Bacitracin Zinc and Hydrocortisone Ophthalmic Ointment.

Assay preparation-Transfer 3.0 mL of Otic Suspension, freshly mixed and free from air bubbles, to a 200-mL. volumetric flask, dilute with a mixture of methanol and water (1:1) to volume, and mix. Filter the solution, rejecting the first 10 mL of the filtrate.

Procedure-Proceed as directed for Procedure in the Assay for hydrocortisone under Neomycin and Polymyxin B Sulfates, Bacitracin Zinc and Hydrocortisone Ophthalmic Ointment. Calculate the quantity, in mg, of C₂₁H₃₀O₅ in each mL of the Otic Suspension taken by the formula:

(66.67C)(r_u /r_s )

in which C is the concentration, in mg per mL, of USP Hydrocortisone RS in the Standard preparation; and r_u and r_s are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.