Potassium Bicarbonate Effervescent Tablets for Oral Solution

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

Potassium Bicarbonate Effervescent Tablets for Oral Solution contain NLT 90.0% and NMT 110.0% of the labeled amount of potassium (K).

2 IDENTIFICATION

Change to read:

A. The retention time of the potassium peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay. (USP 1-Aug-2021)

B. Identification Tests—General 〈191〉, Chemical Identification Tests, Bicarbonate

Sample solution: One Tablet dissolves in 100 mL of water with effervescence.

Acceptance criteria: The collected gas meets the requirements of test A.

3 ASSAY

Change to read:

Procedure

Use water with a resistivity of NLT 18 megohm-cm to prepare the solutions.

Mobile phase: 4 mM nitric acid

System suitability solution: 40 µg/mL of USP Potassium Bicarbonate RS and 15 µg/mL of magnesium¹ in water Standard stock solution: 1000 µg/mL of potassium, equivalent to 2560 µg/mL of USP Potassium Bicarbonate RS, prepared as follows. Transfer an appropriate portion of USP Potassium Bicarbonate RS to a suitable volumetric flask. Add about 30% of the nal volume of water, swirl until effervescence ceases, and mix. Dilute with water to volume.

Standard solution: 15 µg/mL of potassium in water from the Standard stock solution

Sample stock solution: Nominally 5 mg/mL of potassium prepared as follows. Finely powder NLT 20 Tablets and transfer an appropriate portion of the powder to a suitable volumetric flask. Add about 30% of the nal volume of water, swirl until effervescence ceases, and mix. Dilute with water to volume. Pass through a suitable filter, if necessary.

Sample solution: Nominally 15 µg/mL of potassium in water from the Sample stock solution

3.1 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: Conductivity

Columns

Guard: 4-mm × 0.5-cm; 5-µm packing L76

Analytical: 4-mm × 15-cm; 5-µm packing L76

Column temperature: 30°

Flow rate: 0.9 mL/min

Injection volume: 20 µL

Run time: NLT 2 times the retention time of potassium

3.2 System suitability

Samples: System suitability solution and Standard solution

[Note—The relative retention times for the potassium and magnesium ions are 1.0 and 1.3, respectively.]

Suitability requirements

Resolution: NLT 3.0 between the potassium and magnesium ions, System suitability solution

Tailing factor: NMT 2.0, Standard solution

Relative standard deviation: NMT 2.0%, Standard solution

3.3 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of potassium (K) in the portion of Tablets taken:

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

r_U = peak response of potassium from the Sample solution

r_S = peak response of potassium from the Standard solution

C_S = concentration of potassium in the Standard solution (µg/mL)

C_U = nominal concentration of potassium in the Sample solution (µg/mL)

 (USP 1-Aug-2021)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers, protected from excessive heat.

Labeling: The label states the potassium content in terms of weight and in terms of milliequivalents. Where the Tablets are packaged in individual pouches, the label instructs the user not to open until the time of use.

Add the following:

USP Reference Standards 〈11〉

USP Potassium Bicarbonate RS (USP 1-Aug-2021)

¹ From commercially available National Institute of Standards and Technology (NIST)–traceable standard solution for magnesium.