Amoxicillin Tablets 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 Tablets for Oral Suspension contain NLT 90.0% and NMT 110.0% of the labeled amount of amoxicillin (C₁₆H₁₉N₃O₅S). 

2 IDENTIFICATION

A. Thin-Layer Chromatographic Identification Test 〈201〉

Standard solution: 4 mg/mL of USP Amoxicillin RS in 0.1 N hydrochloric acid. Use within 10 min of preparation.

Sample solution: An aqueous dispersion of Tablets for Oral Suspension in 0.1 N hydrochloric acid containing 4 mg/mL of amoxicillin. Use within 10 min of preparation.

2.1 Chromatographic system

Adsorbent: 0.25-mm layer of chromatographic silica gel mixture

Application volume: 5 µL

Developing solvent system: Methanol, chloroform, pyridine, and water (90:80:1:30)

Spray reagent: 3 mg/mL of ninhydrin in alcohol

2.2 Analysis

Samples: Standard solution and Sample solution

Proceed as directed in the chapter. Dry the plate with the aid of a current of warm air for 10 min. Spray lightly with Spray reagent, and dry at 110° for 15 min.

Acceptance criteria: The R value of the principal spot of the Sample solution corresponds to that of the Standard solution. F

3 ASSAY

Procedure

Diluent: 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 Diluent (1:24). Decrease the acetonitrile concentration to increase the retention time of amoxicillin. Standard solution: 1.2 mg/mL of USP Amoxicillin RS in Diluent. Use this solution within 6 h.

Sample solution: Prepare a dispersion of 20 Tablets for Oral Suspension using a suitable aliquot of water. Dilute a portion of the dispersion with Diluent to obtain a solution containing 1.2 mg/mL of amoxicillin. Pass a portion of the solution through a filter of 1-µm or finer pore size. 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; packing L1

Flow rate: 1.5 mL/min

Injection volume: 10 µL

System suitability

Sample: Standard solution

Suitability requirements

Capacity factor: 1.1–2.8

Column efficiency: NLT 1700 theoretical plates

Tailing factor: NMT 2.5

Relative standard deviation: NMT 2.0%

3.2 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of amoxicillin (C₁₆H₁₉N₃O₅S) in the portion of Tablets 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 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%–110.0%

4 PERFORMANCE TESTS

4.1 Disintegration 〈701〉

Medium: Water at 20 ± 5°

Time: 3 min

Acceptance criteria: Meet the requirements

4.2 Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 2: 75 rpm

Time: 30 min

Buffer: 27.2 g of monobasic potassium phosphate in 3 L of water. Adjust with a 45% (w/w) solution of potassium hydroxide to a pH of 5.0 ± 0.1, and dilute with water to obtain 4 L of solution.

Mobile phase: Acetonitrile and Buffer (10:390). Pass through a filter of 0.5-µm or finer pore size.

Standard solution: 0.05 mg/mL of USP Amoxicillin RS in Buffer. Use this solution within 6 h.

Sample solution: Pass a portion of the sample through a filter of 0.5-µm or finer pore size. Dilute a suitable aliquot of the filtrate with water to obtain a concentration of 0.045 mg/mL of amoxicillin. Use this solution within 6 h.

4.2.1 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 230 nm

Columns

Guard: 2-mm × 2-cm; packing L2

Analytical: 3.9-mm × 30-cm; packing L1

Column temperature: 40 ± 1°

Flow rate: 0.7 mL/min

Injection volume: 10 µL

4.2.2 System suitability

Sample: Standard solution

Suitability requirements

Capacity factor: 1.1–2.8

Column efficiency: NLT 1700 theoretical plates

Tailing factor: NMT 2.5

Relative standard deviation: NMT 1.5%

4.2.3 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of amoxicillin (C₁₆H₁₉N₃O₅S) dissolved:

Result = (r_U /r_S) × C_S × V × D × P × F × (1/L) × 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)

V = volume of medium, 900 mL

D = dilution factor

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

F = conversion factor, 0.001 mg/µg

L = label claim (mg/Tablet)

Tolerances: NLT 80% (Q) of the labeled amount of amoxicillin (C₁₆H₁₉N₃O₅S) is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 SPECIFIC TESTS

Dispersion Fineness: Place 2 Tablets for Oral Suspension in 100 mL of water, and stir until completely dispersed. A smooth dispersion that passes through a No. 25 sieve is obtained.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

USP Reference Standards 〈11〉

USP Amoxicillin RS