Dilute Hydrogen Peroxide Solution
(Ph. Eur. monograph 0395)
Action and use
Antiseptic; deodorant.
When hydrogen peroxide is prescribed or demanded, Hydrogen Peroxide Solution (6 per cent) shall be dispensed or supplied.
DEFINITION
Content
2.5 per cent m/m to 3.5 per cent m/m of H2O2 (Mr 34.01).
1 volume of hydrogen peroxide solution (3 per cent) corresponds to about 10 times its volume of oxygen. A suitable stabiliser may be added.
CHARACTERS
Appearance
Colourless, clear liquid.
IDENTIFICATION
A. To 2 mL, add 0.2 mL of dilute sulfuric acid R and 0.2 mL of 0.02 M potassium permanganate. The solution becomes colourless or slightly pink within 2 min.
B. To 1 mL, add 0.1 mL of dilute hydrochloric acid R and 0.1 mL of potassium iodide solution R. A brown colour appears.
Black particles may be formed.
C. It complies with the requirement for the content of H2O2.
TESTS
Acidity
Hydrogen Peroxide Solution (3 per cent)
To 10 mL, add 20 mL of water R and 0.25 mL of methyl red solution R. Not less than 0.05 mL and not more than 1.0 mL of 0.1 M sodium hydroxide is required to change the colour of the indicator.
Organic stabilisers
Maximum 250 ppm.
Shake 20 mL with 10 mL of chloroform R and then with 2 quantities, each of 5 mL, of chloroform R. Evaporate the combined chloroform layers under reduced pressure at a temperature not exceeding 25 °C and dry in a desiccator. The residue weighs a maximum of 5 mg.
Non-volatile residue
Maximum 2 g/L.
Allow 10 mL to stand in a platinum dish until all effervescence has ceased. Evaporate to dryness on a water-bath and dry at 100-105 °C. The residue weighs a maximum of 20 mg.
ASSAY
Dilute 10.0 g to 100.0 mL with water R. To 10.0 mL of this solution add 20 mL of dilute sulfuric acid R. Titrate with 0.02 M potassium permanganate until a pink colour is obtained.
1 mL of 0.02 M potassium permanganate is equivalent to 1.701 mg of H2O2 or 0.56 mL of oxygen.
STORAGE
Protected from light, and if the solution does not contain a stabiliser, at a temperature below 15 °C.
LABELLING
If the solution contains a stabiliser, the label states that the contents are stabilised. The competent authority may require that the name of the stabiliser be stated on the label.
CAUTION
It decomposes in contact with oxidisable organic matter and with certain metals and if allowed to become alkaline.
