Ferrous Fumarate Capsules

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

Ferric iron

In a flask with a ground-glass stopper dissolve a quantity of the mixed contents of 20 capsules 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 0.05m 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 ion. The difference between the titrations is not more than 5.4 mL (1%).

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 2, rotating the paddle at 50 revolutions per minute.

(b) Use 900 mL of 0.1m hydrochloric acid, at a temperature of 37°, as the medium.

procedure

(1) After 45 minutes withdraw a 100 mL sample of the medium and titrate the filtered sample 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).

Assay

Dissolve a quantity of the mixed contents of 20 capsules 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.