Sodium Chloride

Sodium Chloride

NaCl  58.44

Action and use

Used in treatment of electrolyte deficiency.

DEFINITION

Sodium chloride contains not less than 99.0 per cent and not more than the equivalent of 100.5 per cent of NaCl, calculated with reference to the dried substance.

CHARACTERS

A white, crystalline powder or colorless crystals or white pearls, freely soluble in water, practically insoluble in ethanol.

IDENTIFICATION

 A. It gives the reactions of chlorides.

 B. It gives the reactions of sodium.

TESTS

If the substance is in the form of pearls crush before use.

Solution S

Dissolve 20.0 g in carbon dioxide-free water R prepared from distilled water R and dilute to 100.0 ml with the same solvent.

Appearance of solution

Solution S is clear and colorless.

Acidity or alkalinity

To 20 ml of solution S add 0.1 ml of bromothymol blue solution R1. Not more than 0.5 ml of 0.01 M hydrochloric acid or 0.01 M sodium hydroxide is required to change the color of the indicator.

Bromides

To 0.5 ml of solution S add 4.0 ml of water R, 2.0 ml of phenol red solution R2 and 1.0 ml of a 0.1 g/l solution of chloramine R and mix immediately. After exactly 2 min, add 0.15 ml of 0.1 M sodium thiosulphate, mix and dilute to 10.0 ml with water R.  The absorbance 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 5.0 ml of a 3.0 mg/l solution of potassium bromide R  (100 ppm).

Ferrocyanides

Dissolve 2.0 g in 6 ml of water R. Add 0.5 ml of a mixture of 5 ml of a 10 g/l solution  of ferric ammonium sulphate R in a 2.5 g/l solution of sulphuric acid R and 95 ml of a  10 g/l solution of ferrous sulphate R. No blue color develops within 10 min.

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 sulphuric acid, 25 ml of iodide-free starch solution R and 25 ml of water R. After 5 min, examine in daylight. The substance shows no blue color.

Nitrites

To 10 ml of solution S add 10 ml of water R. Measure the absorbance of the solution at 354 nm. The absorbance is not greater than 0.01.

Phosphates

Dilute 2 ml of solution S to 100 ml with water R. The solution complies with the limit test for phosphates (25 ppm).

Sulphates

Dilute 7.5 ml of solution S to 30 ml with distilled water R. 15 ml of the solution complies with the limit test for sulphates (200 ppm).

Aluminium

If intended for use in the manufacture of peritoneal dialysis solutions, haemodialysis solutions or haemofiltration solutions, it complies with the test for aluminium.  Dissolve 20.0 g in 100 ml of water R and add 10 ml of acetate buffer solution pH 6.0 R. The solution complies with the limit test for aluminium (0.2 ppm). Use as the reference solution a mixture of 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. To prepare the blank, use a mixture of 10 ml of acetate buffer solution pH 6.0 R and 100 ml of water R.

Arsenic

5 ml of solution S complies with limit test A for arsenic (1 ppm).

Barium

To 5 ml of solution S add 5 ml of distilled water R and 2 ml of dilute sulphuric acid R.  After 2 h, any opalescence in the solution is not more intense than that in a mixture of 5 ml of solution S and 7 ml of distilled water R.

Iron

10 ml of solution S complies with the limit test for iron (2 ppm). Prepare the standard using a mixture of 4 ml of iron standard solution (1 ppm Fe) R and 6 ml of water R.

Magnesium and alkaline-earth metals

10.0 g complies with the limit test for magnesium and alkaline-earth metals (use 150 mg of mordant black 11 triturate R. The volume of 0.01 M sodium edetate used does not exceed 2.5 ml (100 ppm, calculated as Ca).

Potassium

If intended for use in the manufacture of parenteral dosage forms or haemodialysis, haemofiltration or peritoneal dialysis solutions, it contains not more than 500 ppm of K, determined by atomic emission spectrometry.

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 Dissolve 1.144 g of potassium chloride R, previously dried at  100-105 °C for 3 h, in water R and dilute to 1000.0 ml with the same solvent (600 µg  of K per milliliter). Dilute as required.

Measure the emission intensity at 766.5 nm.

Heavy metals

12 ml of solution S complies with limit test A for heavy metals (5 ppm). Prepare the standard using lead standard solution (1 ppm Pb) R.

Loss on drying

Not more than 0.5 per cent, determined on 1.000 g by drying in an oven at 100-105 °C for 2 h.

Bacterial endotoxins

Less than 5 IU/g, if intended for use in the manufacture of parenteral dosage forms without a further appropriate procedure for removal of bacterial endotoxins.

ASSAY

Dissolve 50.0 mg in water R and dilute to 50 ml with the same solvent. Titrate with 0.1 M silver nitrate determining the end-point potentiometrically.

1 ml of 0.1 M silver nitrate is equivalent to 5.844 mg of NaCl.