Calcium Lactate Monohydrate

(Ph. Eur. monograph 2117)

C₆H₁₀CaO₆,H₂O    236.0    41372-22-9

         (anhydrous)

Used in treatment of calcium deficiency.

Ph Eur

Calcium bis(2-hydroxypropanoate) or mixture of calcium (2R)-, (2S)- and (2RS)-2-hydroxypropanoates monohydrates.

98.0 per cent to 102.0 per cent (dried substance).

White or almost white, crystalline or granular powder.

Soluble in water, freely soluble in boiling water, very slightly soluble in ethanol (96 per cent).

A. Loss on drying (see Tests).

B. It gives the reaction of lactates (2.3.1).

C. It gives reaction (b) of calcium (2.3.1).

Dissolve 5.4 g (equivalent to 5.0 g of the dried substance) with heating in carbon dioxide-free water R prepared from distilled water R, allow to cool and dilute to 100 mL with the same solvent.

Solution S is not more opalescent than reference suspension II (2.2.1) and not more intensely coloured than reference solution BY₆ (2.2.2, Method II).

To 10 mL of solution S add 0.1 mL of phenolphthalein solution R and 0.5 mL of 0.01 M hydrochloric acid. The solution is colourless. Not more than 2.0 mL of 0.01 M sodium hydroxide is required to change the colour of the indicator to pink.

Maximum 200 ppm.

Dilute 5 mL of solution S to 15 mL with water R.

Maximum 400 ppm.

Dilute 7.5 mL of solution S to 15 mL with distilled water R.

To 10 mL of solution S add 1 mL of calcium sulfate solution R. Allow to stand for 15 min. Any opalescence in the solution is not more intense than that in a mixture of 1 mL of distilled water R and 10 mL of solution S.

Maximum 50 ppm.

Dilute 4 mL of solution S to 10 mL with water R.

Maximum 1 per cent.

To 20 mL of solution S add 20 mL of water R, 2 g of ammonium chloride R and 2 mL of dilute ammonia R1. Heat to boiling and rapidly add 40 mL of hot ammonium oxalate solution R. Allow to stand for 4 h, dilute to 100.0 mL with water R and filter. To 50.0 mL of the filtrate add 0.5 mL of sulfuric acid R. Evaporate to dryness and ignite the residue to constant mass at 600 ± 50 °C. The residue weighs a maximum of 5 mg.

Maximum 10 ppm.

Dissolve a quantity equivalent to 2.0 g of the dried substance in water R and dilute to 20 mL with the same solvent. 12 mL of the solution complies with test A. Prepare the reference solution using lead standard solution (1 ppm Pb) R.

5.0 per cent to 8.0 per cent, determined on 0.500 g by drying in an oven at 125 °C.

Dissolve a quantity equivalent to 0.200 g of the dried substance in water R and dilute to 300 mL with the same solvent. Carry out the complexometric titration of calcium (2.5.11).

1 mL of 0.1 M sodium edetate is equivalent to 21.82 mg of C₆H₁₀CaO₆.

Ph Eur