Potassium Gluconate Tablets

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

Potassium Gluconate Tablets contain NLT 95.0% and NMT 105.0% of the labeled amount of potassium gluconate (C₆H₅K₃O₇).

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197M (CN 1-May-2020) : The IR absorption spectrum of potassium gluconate extracted from finely powdered Tablets exhibits maxima only at the same wavelengths as those of a similar preparation of USP Potassium Gluconate RS.

B.

Sample solution: Triturate a portion of powdered Tablets with a few milliliters of water, and filter.

Acceptance criteria: The Sample solution imparts a violet color to a nonluminous flame; the presence of small quantities of sodium masks the color, unless the yellow color produced by sodium is screened out by viewing through a blue filter that blocks the emission at 589 nm (sodium); it is transparent to the emission at 404 nm (potassium). [Note - Traditionally, cobalt glass has been used, but other suitable filters are commercially available.]

3 ASSAY

Procedure

Standard stock solution: 19.07 μg/mL of potassium chloride in water (equivalent to 10 μg/mL of potassium), prepared from potassium chloride previously dried at 105° for 2 h

Standard solutions: 1.0, 1.5, and 2.0 μg/mL of potassium from suitably diluted Standard stock solution, in a solution containing 4 mg/mL of sodium chloride and 1 mL of hydrochloric acid per 100 mL

Sample stock solution: Filtered water solution containing 0.18 mg/mL of potassium gluconate from NLT 20 finely powdered Tablets

Sample solution: Transfer 5.0 mL of Sample stock solution to a 100-mL volumetric flask. Add 2.0 mL of a 200-mg/mL sodium chloride solution and 1.0 mL of hydrochloric acid, and dilute with water to volume.

Blank: Water

Instrumental conditions

(See Atomic Absorption Spectroscopy 〈852〉.)

Mode: Atomic absorption spectrophotometry

Analytical wavelength: 766.5 nm

Lamp: Potassium hollow-cathode

Flame: Air–acetylene

Analysis

Samples: Standard solutions and Sample solution

Determine the absorbances of the Standard solutions and the Sample solution. Plot the absorbances of the Standard solutions versus their concentrations, in μg/mL, of potassium, and draw the straight line best fitting the three plotted points. From the graph so obtained, determine the concentration, C, in μg/mL, of potassium in the Sample solution.

Calculate the percentage of the labeled amount of potassium gluconate (C₆H₅K₃O₇) in the portion of Tablets taken:

Result = (C/C_U) × (M_r/A_r) × 100

C = determined concentration of potassium in the Sample solution (μg/mL)

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

M_r = molecular weight of potassium gluconate, 234.25

A_r = atomic weight of potassium, 39.10

Acceptance criteria: 95.0%–105.0%

4 PERFORMANCE TESTS

Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 2: 100 rpm

Time: 45 min

Sample solution: Filtered portion of the solution under test, suitably diluted with Medium if necessary

Analysis: Proceed as directed in the Assay.

Calculate the percentage of the labeled amount of potassium gluconate (C₆H₅K₃O₇) dissolved:

Result = (C × D × V/L) × (M_r/A_r) × 100

C = determined concentration of potassium in the Sample solution (mg/mL)

D = dilution factor for the Sample solution

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

M_r = molecular weight of potassium gluconate, 234.25

A_r = atomic weight of potassium, 39.10

Tolerances: NLT 75% (Q) of the labeled amount of potassium gluconate (C₆H₅K₃O₇) is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements

5 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

USP Reference Standards 〈11〉

USP Potassium Gluconate RS