Potassium Gluconate and Potassium Citrate Oral Solution
» Potassium Gluconate and Potassium Citrate Oral Solution is a solution of Potassium Gluconate and Potassium Citrate in a suitable aqueous medium. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of potassium (K).
Packaging and storage Preserve in tight containers.
Labeling Label it to state the potassium content in terms of milliequivalents in a given volume of Oral Solution.
A: To 2 mL of a dilution of Oral Solution (1 in 40) add 5 mL of sodium cobaltinitrite TS: a yellow precipitate is formed immediately (presence of potassium).
B: It responds to the test for Citrate 191, 3 to 5 drops of Oral Solution and 20 mL of the mixture of pyridine and acetic anhydride being used.
Assay for potassium
Potassium stock solution Dissolve in water 0.9535 g of potassium chloride, previously dried at 105 for 2 hours. Transfer to a 500-mL volumetric flask, dilute with water to volume, and mix. This solution contains 1000 µg of potassium per mL.
Standard preparations To separate 200-mL volumetric flasks transfer 19.0 mL and 25.0 mL, respectively, of Potassium stock solution, dilute with water to volume, and mix. The Standard preparations contain 95.0 µg and 125.0 µg of potassium per mL, respectively.
Assay preparation Transfer an accurately measured volume of Oral Solution, equivalent to about 782 mg (20 mEq) of potassium, to a 100-mL volumetric flask, dilute with water to volume, and mix. Transfer 7.0 mL of this solution to a 500-mL volumetric flask, dilute with water to volume, and mix.
Procedure Concomitantly determine the absorbances of the Standard preparations and the Assay preparation at the resonance line of 766.5 nm, with a suitable atomic absorption spectrophotometer (see Spectrophotometry and Light-scattering 851) equipped with a potassium hollow-cathode lamp and an airacetylene flame, using water as the blank. Plot the absorbances of the Standard preparations versus concentration, in µg per mL, of potassium. From the graph so obtained, determine the concentration, C, in µg per mL, of potassium in the Assay preparation. Calculate the quantity, in mg, of potassium in each mL of the Oral Solution taken by the formula:
(50 / 7)(C / V)in which V is the volume, in mL, of Oral Solution taken. Each mg of potassium is equivalent to 0.02558 mEq.