Sodium Stibogluconate BP Grade

16037-91-5

DEFINITION
Sodium Stibogluconate is mainly the disodium salt of μ-oxy-bis[gluconato(3-)-c2,c3,c4hydroxoantimony]. It contains not less than 30.0% and not more than 34.0% of antimony(V), calculated with reference to the dried and methanol-free substance.

PRODUCTION
The method of manufacture is such as to ensure consistently controlled reaction stoichiometry in order to yield sodium stibogluconate that is satisfactory with regard to intrinsic toxicity.

CHARACTERISTICS
A colourless, mostly amorphous powder.
Very soluble in water; practically insoluble in ethanol (96%) and in ether.

IDENTIFICATION
A. A solution is dextrorotatory.
B. Pass hydrogen sulphide into a 5% w/v solution for several minutes. An orange precipitate is produced.
C. When heated, it chars without melting leaving a residue which yields the reactions characteristic of antimony compounds and the reactions characteristic of sodium salts.

TESTS
Stability and acidity of solution: Heat a solution containing the equivalent of 10% w/v of antimony(V) in an autoclave at 115.5C and at a pressure of 70 kPa for 30 minutes. The resulting solution is colourless or almost colourless and has a pH of 5.0 to 5.6.
Antimony(III): Dissolve 2 g in 30 ml of water, add 15 ml of hydrochloric acid and titrate with 0.00833M potassium bromate using methyl orange solution as indicator. Not more than 1.3 ml of 0.00833M potassium bromate is required.
Chloride: Dissolve 2.5 g in 50 ml of water and add 2 ml of 2M nitric acid and 75 ml of acetate buffer pH 5.0 . Titrate with 0.1M silver nitrate determining the end point potentiometrically. Not more than 3.0 ml of 0.1M silver nitrate is required.
Methanol: Not more than 2.0% w/w when determined by the method.
Loss on drying: When dried to constant weight at 130C at a pressure not exceeding 0.7 kPa, loses not more than 15.0% of its weight. Use 1 g.
ASSAY: Dissolve 0.16 g in 30 ml of hydrochloric acid , add 70 ml of orthophosphoric acid and stir carefully until completely mixed. Titrate with 0.05M ammonium iron( II ) sulphate prepared using sulphuric acid (1%) and determining the end point potentiometrically using a platinum electrode and a silver-silver chloride reference electrode. Each ml of 0.05M ammonium iron(II) sulphate is equivalent to 3.044 mg of antimony(V).