Cefdinir 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

Cefdinir for Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled amount of cefdinir (C₁₄H₁₃N₅O₅S₂). It may contain one or more suitable buffers, flavors, preservatives, stabilizing agents, sweeteners, and suspending agents.

2 IDENTIFICATION

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

B. The UV spectrum of the cefdinir peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

3.1 PROCEDURE

Buffer: 10.7 g/L of sodium phosphate, dibasic, anhydrous and 3.4 g/L of potassium phosphate, monobasic in water. Adjust with phosphoric acid or sodium hydroxide to a pH of 7.0.

Solution A: 7 g/L of citric acid monohydrate. Adjust with phosphoric acid to a pH of 2.0.

Mobile phase: Methanol, tetrahydrofuran, and Solution A (111:28:1000)

System suitability solution: 50 µg/mL of USP Cefdinir RS and 175 µg/mL of m-hydroxybenzoic acid in Buffer Standard solution: 50 µg/mL of USP Cefdinir RS in Buffer

Sample solution: Nominally 50 µg/mL of cefdinir from constituted Cefdinir for Oral Suspension in Buffer

3.1.1 Chromatographic system

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

Detector: UV 254 nm. For Identification B, use a diode array detector in the range of 200–400 nm. Column: 3.9-mm × 15-cm; 4-µm packing L1

Flow rate: 1.4 mL/min Injection volume: 15 µL

Run time: NLT 3 times the retention time of cefdinir

3.1.2 System suitability

Samples: System suitability solution and Standard solution Suitability requirements

Resolution: NLT 3.0 between cefdinir and m-hydroxybenzoic acid, System suitability solution Tailing factor: NMT 2.0 for cefdinir, System suitability solution

Relative standard deviation: NMT 1.0% for cefdinir, Standard solution Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of cefdinir (C₁₄H₁₃N₅O₅S₂) in the portion of Cefdinir for Oral Suspension taken:

Result = (r_u/r_s) × (C_s/C_u) × 100

r_u = peak response of cefdinir from the Sample solution

r_s = peak response of cefdinir from the Standard solution

C_s = concentration of USP Cefdinir RS in the Standard solution (µg/mL)

C_u = nominal concentration of cefdinir in the Sample solution (µg/mL)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

4.1 DISSOLUTION 〈711〉

Medium: 0.05 M phosphate buffer, pH 6.8; 900 mL

Apparatus 2: 50 rpm

Time: 30 min

Standard solution: 0.14 mg/mL of USP Cefdinir RS in Medium

Sample solution: Transfer 5 mL, by weight, of the reconstituted Cefdinir for Oral Suspension into the vessel. After the appropriate time, withdraw a portion of the solution under test, and pass it through a suitable filter of 0.45-µm pore size. Dilute a portion of each filtered sample with Medium as necessary to obtain a solution with a concentration of about 0.14 mg/mL of cefdinir.

Instrumental conditions Mode: UV

Analytical wavelength: 290 nm Blank: Medium

4.1.1 Analysis

Samples: Standard solution and Sample solution

Determine the percentage of the labeled amount of cefdinir (C₁₄H₁₃N₅O₅S₂) dissolved:

Result = (A_u/A_s) × C_s × (d/W) × V × D × (1/L) × 100

A_u = absorbance from the Sample solution

A_s = absorbance from the Standard solution

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

d    = density of Cefdinir for Oral Suspension (mg/mL)

W  = weight of reconstituted Cefdinir for Oral Suspension taken (mg)

V    = volume of Medium, 900 mL

D    = dilution factor for the Sample solution (mL/mL)

L    = label claim (mg/mL)

Tolerances: NLT 80% (Q ) of the labeled amount of cefdinir (C H N O S ) is dissolved.

4.2 UNIFORMITY OF DOSAGE UNITS 〈905〉

For single-unit containers: Meets the requirements

5 DELIVERABLE VOLUME 〈698〉

For multiple-unit containers: Meets the requirements

6 IMPURITIES

ORGANIC IMPURITIES

Solution A: 14.2 g/L of sodium phosphate, dibasic, anhy drous Solution B: 13.6 g/L of potassium phosphate, monobasic

Buffer: Combine appropriate amounts of Solution A and Solution B (about 2:1) to obtain a solution with a pH of 7.0.

Solution C: Dilute tetramethylammonium hydroxide TS with water to obtain a 0.1% solution. Adjust with 10% phosphoric acid TS to a pH of 5.5.

Solution D: 37.2 g/L of edetate disodium

Solution E: To 1000 mL of Solution C add 0.4 mL of Solution D.

Solution F: Acetonitrile, methanol, Solution C, and Solution D (150: 100: 250: 0.2) Mobile phase: See Table 1.