Action and use
Sulfonamide antibacterial.
DEFINITION
Sulfadimidine Injection is a sterile solution of sulfadimidine sodium in Water for Injections free from dissolved air. It is prepared by the interaction of Sulfadimidine and Sodium Hydroxide.
The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
Content of sulfadimidine sodium, C12H13N4NaO2S
95.0 to 105.0% of the stated amount.
IDENTIFICATION
A. Acidify a volume containing 0.1 g of sulfadimidine sodium with 6M acetic acid, filter, reserving the filtrate, wash the residue with water and dry at 105°. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of sulfadimidine (RSV 50).
B. The residue obtained in test A yields the reaction characteristic of primary aromatic amines, Appendix VI, producing a bright orange-red precipitate.
TESTS
Alkalinity
pH, 10.0 to 11.0, Appendix V L.
Colour of solution
An injection containing 1 g of sulfadimidine sodium in 3 mL is not more intensely coloured than reference solution Y4, Appendix IV B, Method I.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using silica gel H as the coating substance and a mixture of 18 volumes of 10M ammonia and 90 volumes of butan-1-ol as the mobile phase. Apply separately to the plate
10 μL of each of the following solutions. For solution (1) use the injection being examined diluted with water to contain 0.20% w/v of sulfadimidine sodium. Solution (2) contains 0.0020% w/v of sulfanilamide in a mixture of 1 volume of 13.5M ammonia and 9 volumes of ethanol (96%). After removal of the plate, heat it at 105° for 10 minutes and spray with a 0.1% w/v solution of 4-dimethylaminobenzaldehyde in ethanol (96%) containing 1% v/v of hydrochloric acid. Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (1%).
ASSAY
Dilute a volume containing 0.5 g of sulfadimidine sodium to 75 mL with water, add 10 mL of hydrochloric acid and pass air slowly through the solution until the vapours do not turn moistened starch iodate paper blue. Add 3 g of potassium bromide, cool in ice and titrate slowly with 0.1M sodium nitrite VS, stirring constantly and determining the end point electrometrically. Each mL of 0.1M sodium nitrite VS is equivalent to 30.03 mg of C12H13N4NaO2S.
STORAGE
Sulfadimidine Injection should be protected from light.
LABELLING
The strength is stated as the amount of sulfadimidine sodium in a suitable dose-volume.
