Amoxicillin 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

Amoxicillin for Oral Suspension contains the equivalent of NLT 90.0% and NMT 120.0% of the labeled amount of amoxicillin (C₁₆H₁₉N₃O₅S). It contains one or more suitable buffers, colors, flavors, preservatives, stabilizers, sweeteners, and suspending agents.

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

Buffer: Dissolve 6.8 g/L of monobasic potassium phosphate in water. Adjust with a 45% (w/w) solution of potassium hydroxide to a pH of 5.0 ± 0.1.

Mobile phase: Acetonitrile and Buffer (1:24)

Standard solution: 1.2 mg/mL of USP Amoxicillin RS in Buffer. [Note—Use this solution within 6 h.]

Sample solution: Dilute a measured volume of Amoxicillin for Oral Suspension, constituted as directed in the labeling, freshly mixed and free from air bubbles, quantitatively and stepwise in Buffer to obtain a solution containing nominally 1 mg/mL of anhydrous amoxicillin. Pass a portion of this solution through a suitable filter. [Note—Use this solution within 6 h.]

3.1 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 230 nm

Column: 4-mm × 25-cm;10-µm packing L1

Flow rate: 1.5 mL/min

Injection size: 10 µL

3.2 System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 2.5

Relative standard deviation: NMT 2.0%

3.3 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of C₁₆H₁₉N₃O₅S in the Amoxicillin for Oral Suspension taken:

Result = (r_U /r_S) × (C_S /C_U) × P × F × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

C_S = concentration of USP Amoxicillin RS in the Standard solution (mg/mL)

C_U = nominal concentration of anhydrous amoxicillin in the Sample solution (mg/mL)

P = potency of amoxicillin in USP Amoxicillin RS (µg/mg)

F = conversion factor, 0.001 mg/µg

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〉: 5.0–7.5, in the suspension constituted as directed in the labeling

Microbial Enumeration Tests 〈61〉andTests for Specified Microorganisms 〈62〉: The total aerobic microbial count does not exceed 103 cfu/g, and the total combined molds and yeasts count does not exceed 102 cfu/g.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers, and store at controlled room temperature.

USP Reference Standards 〈11〉

USP Amoxicillin RS