EUROPEAN PHARMACOPOEIA 7.0
Potassium citrate
01/2008:0185 corrected 7.0
POTASSIUM CHLORIDE
Kalii chloridum
KCl M, 74.6
17447-40-7]
DEFINITION
Content: 99.0 per cent to 100.5 per cent of KCl (dried substance).
CHARACTERS
Appearance: white or almost white, crystalline powder or colourless crystals.
Solubility: freely soluble in water, practically insoluble in anhydrous ethanol.
IDENTIFICATION
A. It gives the reactions of chlorides (2.3.1).
B. Solution S (see Tests) gives the reactions of potassium (2.3.1).
TESTS
Solution S. Dissolve 10.0 g in carbon dioxide-free water R prepared from distilled water R and dilute to 100 mL with the same solvent.
Appearance of solution. Solution S is clear (2.2.1) and colourless (2.2.2, Method If).
Acidity or alkalinity. To 50 mL of solution S add 0.1 mL of
bromothymolblue solution Rl. Not more than 0.5 mL of 0.01 M hydrochloric acid or 0.01 M sodium hydroxide is required to change the colour of the indicator.
Bromides: maximum 0.1 per cent.
Dilute 1.0 mL of solution S to 50 mL with water R. To 5.0 mL of the solution add 2.0 mL of phenol red solution R2 and 1.0 mL of chloramine solution Rl and mix immediately. After exactly 2 min add 0.15 mL of 0.1 M sodium thiosulfate, mix and dilute to 10.0 mL with water R. The absorbance (2.2.25) of the solution measured at 590 nm, using water R as the compensation liquid, is not greater than that of a standard prepared at the same time and in the same manner using 5 mL of a 3.0 mg/L solution of potassium bromide R.
Iodides. Moisten 5 g by the dropwise addition of a freshly prepared mixture of 0.15 mL of sodium nitrite solution R, 2 mL of 0.5 M sulfuric acid, 25 mL of iodide-ftee starch solution R and 25 mL of water R. After 5 min, examine in daylight. The substance shows no blue colour.
Sulfates (2.4.13): maximum 300 ppm.
Dilute 5 mL of solution S to 15 mL with distilled water R.
Aluminium (2.4.17): maximum 1.0 ppm, if intended for use in the manufacture of haemodialysis solutions.
Prescribed solution. Dissolve 4 g in 100 mL of water R and add 10 mL of acetate buffer solution pH 6.0 R.
Reference solution. Mix 2 mL of aluminium standard solution (2 ppm Al) R, 10 mL of acetate buffer solution pH 6.0 R and 98 mL of water R.
Blank solution. Mix 10 mL of acetate buffer solution pH 6.0 R and 100 mL of water R.
Barium. To 5 mL of solution S add 5 mL of distilled water R and 1 mL of dilute sulfuric acid R. After 15 min, any opalescence in the solution is not more intense than that in a mixture of 5 mL of solution S and 6 mL of distilled water R.
Iron (2.4.9): maximum 20 ppm.
Dilute 5 mL of solution S to 10 mL with water R.
Magnesium and alkaline-earth metals (2.4.7): maximum 200 ppm, calculated as Ca, determined on 10.0 g using 0.15 g of mordant black 11 triturate R. The volume of 0.01 Msodium edetate used does not exceed 5.0 mL.
Sodium: maximum 0.1 per cent, if intended for use in the manufacture of parenteral preparations or haemodialysis solutions.
Atomic emission spectrometry (2.2.22, Method I). Test solution. Dissolve 1.00 g of the substance to be examined in water R and dilute to 100.0 mL with the same solvent. Reference solutions. Prepare the reference solutions by diluting as required a solution containing 200 pg of Na per millilitre, prepared as follows: dissolve in water R 0.5084 g of sodium chloride R, previously dried at 100-105 °C for 3 h, and dilute to 1000.0 mL with the same solvent.
Wavelength: 589 nm.
Heavy metals (2.4.8): maximum 10 ppm.
12 mL of solution S complies with test A. Prepare the reference solution using lead standard solution (1 ppm Pb) R.
Loss on drying (2.2.32): maximum 1.0 per cent, determined on 1.000 g by drying in an oven at 105 °C for 3 h.
ASSAY
Dissolve 1.300 g in water R and dilute to 100.0 mL with the same solvent. To 10.0 mL of the solution add 50 mL of water R, 5 mL of dilute nitric acid R, 25.0 mL of 0.1 M silver nitrate and 2 mL of dibutyl phthalate R. Shake. Titrate with 0.1 M ammonium thiocyanate, using 2 mL of ferric ammonium sulfate solution R2 as indicator and shaking vigorously towards the end-point
1 mL of 0.1 M silver nitrate is equivalent to 7.46 mg of KCl.
LABELLING The label states:
- where applicable, that the substance is suitable for use in the manufacture of parenteral preparations;
- where applicable, that the substance is suitable for use in the manufacture of haemodialysis solutions.
01/2009:0400 corrected 7.0
POTASSIUM CITRATE
Kalii citras
HO CO2K
C6H5K307,H20 M, 324.4
[6100-05^6]
DEFINITION
Tripotassium 2-hydroxypropane-l,2,3-tricarboxylate monohydrate.
Content: 99.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS
Appearance: white or almost white, granular powder or transparent crystals, hygroscopic.
Solubility: very soluble in water, practically insoluble in ethanol (96 per cent).
IDENTIFICATION
A. To 1 mL of solution S (see Tests) add 4 mL of water R. The solution gives the reaction of citrates (2.3.1).
B. 0.5 mL of solution S gives reaction (b) of potassium (2.3.1).
General Notices (1) apply to all monographs and other texts
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