Cefixime for Oral 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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1 DEFINITION

Cefixime for Oral Suspension is a dry mixture of Cefixime and one or more suitable diluents, flavors, preservatives, and suspending agents. It contains the equivalent of NLT 90.0% and NMT 120.0% of the labeled amount of cefixime (C₁₆H₁₅N₅O₇S₂)/mL when constituted as directed in the labeling.

2 IDENTIFICATION

The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

PROCEDURE

Solution A: 0.4 M tetrabutylammonium hydroxide solution and water (1:39). Adjust with 1.5 M phosphoric acid to a pH of 6.5. Solution B: 13.6 mg/mL of monobasic potassium phosphate

Solution C: 14.2 mg/mL of anhydrous dibasic sodium phosphate. Adjust a volume of this solution with a sufficient volume of Solution B to a pH of 7.0.

Mobile phase: Acetonitrile and Solution A (1:3)

System suitability solution: 1 mg/mL of USP Cefixime RS. [NOTE—Heat this solution at 95° in an oil bath for 45 min, cool, and use promptly.] Standard solution: 0.2 mg/mL of USP Cefixime RS in Solution C. [NOTE—Use this solution promptly.]

Sample solution: Constitute Cefixime for Oral Suspension as directed in the labeling. Quantitatively dilute a suitable aliquot of the suspension, freshly mixed and free from air bubbles, with Solution C to obtain a solution having a nominal concentration of 0.2 mg of cefixime/mL.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.) Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 12.5-cm; 4-µm packing L1 Temperature: 40°

Flow rate: Adjust flow rate so that the retention time of cefexime is about 10 min. Injection size: 10 µL

System suitability

Samples: System suitability solution and Standard solution

[NOTE—The relative retention times for cefixime (E)-isomer and cefixime are about 0.9 and 1.0, respectively.] Suitability requirements

Resolution: NLT 2.0 between cefixime and cefixime (E)-isomer, System suitability solution

Column efficiency: NLT 4000 theoretical plates, Standard solution. Use the following formula to calculate column efficiency:

Result = 5.545(t/W_h/2)²

Tailing factor: NLT 0.9 and NMT 2.0 for the analyte peak, Standard solution. Use the following formula to calculate tailing factor:

Result = W_0.1/2f

W_0.1 = peak width at 10% peak height

Relative standard deviation: NMT 2.0%, Standard solution Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of C H N O S in the constituted suspension prepared from the Cefixime for Oral Suspension:

Result = (r_u/r_s) × (C_s/C_u) × 100

r_u = peak response of cefixime from the Sample solution

r_s = peak response of cefixime from the Standard solution

C_s = concentration of USP Cefixime RS in the Standard solution (mg/mL)

C_u = nominal concentration of cefixime in the Sample solution (mg/mL)

Acceptance criteria: 90.0%–120.0%

4 PERFORMANCE TESTS

UNIFORMITY OF DOSAGE UNITS 〈905〉FOR SOLIDS PACKAGED IN SINGLE-UNIT CONTAINERS: Meets the requirements

DELIVERABLE VOLUME 〈698〉: Meets the requirements

5 SPECIFIC TESTS

PH 〈791〉: 2.5–4.5, in the suspension constituted as directed in the labeling

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight containers.

LABELING: Label it to indicate that the cefixime contained therein is in the trihydrate form.

USP REFERENCE STANDARDS 〈11〉

USP Cefixime RS