Edition: BP 2025 (Ph. Eur. 11.6 update)
Action and use
Treatment of iron-deficiency anaemia.
DEFINITION
Ferrous Fumarate Capsules contain Ferrous Fumarate.
The capsules comply with the requirements stated under Capsules and with the following requirements.
Content of ferrous iron, Fe(II)
95.0 to 105.0% of the stated amount.
IDENTIFICATION
A. Heat 1 g of the contents of the capsules with 25 mL of a mixture of equal volumes of hydrochloric acid and water on a water bath for 15 minutes, cool and filter. Retain the residue for test B. The filtrate yields reaction A characteristic of iron salts, Appendix VI.
B. Wash the residue reserved in test A with a mixture of 1 volume of 2M hydrochloric acid and 9 volumes of water and dry at 105°. Suspend 0.1 g of the residue in 2 mL of dilute sodium carbonate solution and add dilute potassium permanganate solution drop wise. The permanganate is decolourised and a brownish solution is produced.
C. Mix a quantity of the contents of the capsules containing 0.5 g of Ferrous Fumarate with 1 g of resorcinol. To 0.5 g of the mixture in a crucible add 0.15 mL of sulfuric acid and heat gently; a deep red, semi-solid mass is produced. Add the mass to a large volume of water; an orange–yellow solution is produced which exhibits no fluorescence.
TESTS
Dissolution
Comply with the requirements for Monographs of the British Pharmacopoeia in the dissolution test for tablets and capsules, Appendix XII B1.
TEST CONDITIONS
(a) Use Apparatus 1, rotating the basket at 100 revolutions per minute.
(b) Use 900 mL of 0.1M hydrochloric acid, at a temperature of 37°, as the medium.
PROCEDURE
After 45 minutes withdraw a sample of the medium and filter. Titrate 100 mL of the filtrate with 0.01M ammonium cerium(IV) sulfate VS using ferroin solution as indicator.
DETERMINATION OF CONTENT
Calculate the total content of Fe(II) in the medium taking each mL of 0.01M ammonium cerium(IV) sulfate VS to be equivalent to 0.5585 mg of Fe(II).
Ferric iron
In a flask with a ground-glass stopper dissolve a quantity of the mixed capsule contents prepared for the Assay containing 1.5 g of Ferrous Fumarate in a mixture of 10 mL of hydrochloric acid and 100 mL of water by heating rapidly to boiling. Boil for 15 seconds. Cool rapidly, add 3 g of potassium iodide, stopper the flask and allow to stand protected from light for 15 minutes. Add 2 mL of starch solution as indicator. Titrate the liberated iodine with 0.1M sodium thiosulfate VS. Carry out a blank test. The difference between the volumes used in the two titrations corresponds to the amount of iodine liberated by ferric iron. The difference between the titrations is not more than 13.4 mL (5%).
ASSAY
Weigh the contents of 20 capsules. Mix and powder if necessary. Dissolve a quantity of the mixed capsule contents containing 0.3 g of Ferrous Fumarate in 7.5 mL of 1M sulfuric acid with gentle heating. Cool, add 25 mL of water and titrate immediately with 0.1M ammonium cerium(IV) sulfate VS using ferroin solution as indicator. Each mL of 0.1M ammonium cerium(IV) sulfate VS is equivalent to 5.585 mg of Fe(II).
LABELLING
The quantity of the active ingredient is stated both as the amount of ferrous fumarate and in terms of the equivalent amount of ferrous iron.
