Neomycin and Polymyxin B Sulfates, Bacitracin Zinc, and Hydrocortisone Ophthalmic Ointment

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

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

DOWNLOAD PDF HERE

1 DEFINITION

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 NLT 90.0% and NMT 140.0% of the labeled amounts of neomycin, polymyxin B, and bacitracin, and NLT 90.0% and NMT 110.0% of the labeled amount of hydrocortisone (C₂₁H₃₀O₅).

2 IDENTIFICATION

A. Thin-Layer Chromatographic Identification Test 〈201BNP〉: Meets the requirements

B. The retention time of the hydrocortisone peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay for Hydrocortisone.

3 ASSAY

3.1 Neomycin

(See Antibiotics-Microbial Assays 〈81〉.)

Sample solution: Shake a portion of Ophthalmic Ointment in a separator with 50 mL of ether. Extract with four 20-mL portions of Buffer B.3. Combine the aqueous extracts, and dilute with Buffer B.3 to a suitable volume.

Analysis: Proceed as directed in the chapter. Dilute the Sample solution with Buffer B.3 to obtain a Test Dilution having a neomycin concentration that is nominally equivalent to the median level of the standard.

Acceptance criteria: 90.0%–140.0%

3.2 Polymyxin B

(See Antibiotics-Microbial Assays 〈81〉.)

Sample solution: Shake a portion of Ophthalmic Ointment with 50 mL of ether in a separator. Extract with four 25-mL portions of Buffer B.6. Combine the aqueous extracts, and dilute with Buffer B.6 to a suitable volume.

Analysis: Proceed as directed in the chapter. Dilute the Sample solution with Buffer B.6 to obtain a Test Dilution having a concentration that is nominally equivalent to the median level of the standard (10 polymyxin B Units/mL). Add to each Test Dilution of the standard a quantity of USP Neomycin Sulfate RS, dissolved in Buffer B.6, to obtain the same concentration of neomycin as in the Test Dilution of the sample.

Acceptance criteria: 90.0%–140.0%

3.3 Bacitracin

(See Antibiotics-Microbial Assays 〈81〉.)

Sample solution: Shake a portion of Ophthalmic Ointment with 50 mL of ether in a separator. Extract with four 25-mL portions of 0.01 N hydrochloric acid. Combine the acid extracts, and dilute with 0.01 N hydrochloric acid to a suitable volume.

Analysis: Proceed as directed in the chapter. Dilute the Sample solution with Buffer B.1 to obtain a Test Dilution having a concentration that is nominally equivalent to the median level of the standard (1.0 bacitracin Unit/mL). If the Sample solution has a concentration of less than 100 bacitracin Units/mL, add hydrochloric acid to each Test Dilution of the standard to obtain the same concentration of hydrochloric acid as in the Test Dilution of the sample.

Acceptance criteria: 90.0%–140.0%

3.4 Hydrocortisone

Mobile phase: Methanol, glacial acetic acid, and water (500:1:500)

Diluent: Methanol and water (1:1)

Standard solution: 0.15 mg/mL of USP Hydrocortisone RS in Diluent

Sample solution: Transfer 1.5 g of Ophthalmic Ointment to a separator. 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 Diluent. Collect the extracts in a 100-mL volumetric flask, dilute with Diluent to volume, and mix. Filter the solution, rejecting the first 10 mL of the filtrate.

Chromatographic system

• (See Chromatography 〈621〉, System Suitability.)
• Mode: LC
• Detector: UV 254 nm
• Column: 3.9-mm × 30-cm; 10-µm packing L1
• Flow rate: 2 mL/min
• Injection volume: 10 µL

System suitability

• Sample: Standard solution
• Suitability requirements
• Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of hydrocortisone (C₂₁H₃₀O₅) in the portion of Ophthalmic Ointment taken:

Result = (rᵤ/rₛ) × (Cₛ/Cᵤ) × 100

rᵤ = peak response from the Sample solution

rₛ = peak response from the Standard solution

Cₛ = concentration of USP Hydrocortisone RS in the Standard solution (mg/mL)

Cᵤ = nominal concentration of hydrocortisone in the Sample solution (mg/mL)

Acceptance criteria: 90.0%–110.0%

4 SPECIFIC TESTS

Sterility Tests 〈71〉: Meets the requirements

Other Requirements: It meets the requirements for Particulate and Foreign Matter and Container Contents in Ophthalmic Products—Quality Tests 〈771〉, Drug Product Quality, Universal Tests, Particulate and Foreign Matter and Container Contents.

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in collapsible ophthalmic ointment tubes.

USP Reference Standards 〈11〉

USP Bacitracin Zinc RS

USP Hydrocortisone RS

USP Neomycin Sulfate RS

USP Polymyxin B Sulfate RS