Edition: BP 2025 (Ph. Eur. 11.6 update)
Diazoxide Injection
General Notices
Action and use
Vasodilator; treatment of hypertension.
DEFINITION
Diazoxide Injection is a sterile solution of Diazoxide in Water for Injections, prepared with the aid of Sodium Hydroxide. The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
Content of diazoxide, C8H7ClN2O2S
95.0 to 105.0% of the stated amount.
CHARACTERISTICS
A colourless solution.
IDENTIFICATION
To a volume containing 0.3 g of Diazoxide add 2 mL of 2M hydrochloric acid, stir, filter the precipitate and wash the filter thoroughly with water until the filtrate is free from acid. The precipitate, after drying at 105°, complies with the following tests.
A. The infrared absorption spectrum, Appendix II A, is concordant with the reference spectrum of diazoxide (RS 094). B. The light absorption, Appendix II B, in the range 230 to 350 nm of a 0.001% w/v solution in 0.1M sodium hydroxide exhibits a maximum only at 280 nm.
C. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions. (1) Use the injection, diluted if necessary, with methanol to contain 0.02% w/v of Diazoxide. (2) 0.02% w/v of diazoxide EPCRS in methanol.
CHROMATOGRAPHIC CONDITIONS
(a) Use as the coating silica gel GF254.
(b) Use the mobile phase as described below.
(c) Apply 5 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow it to dry in air until the solvent has evaporated, examine under ultraviolet light (254 nm) and then treat the plate by Method I and examine again.
MOBILE PHASE
20 volumes of acetone, 30 volumes of ether and 50 volumes of toluene.
CONFIRMATION
The principal spot in the chromatogram obtained with solution (1) corresponds in position and colour to that in the chromatogram obtained with solution (2).
TESTS
Alkalinity
pH, 11.2 to 11.9, Appendix V L.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
(1) Use the injection diluted, if necessary, with 0.1M sodium hydroxide to contain 1.5% w/v of Diazoxide. (2) Dilute 1 volume of solution (1) to 200 volumes with 0.1M sodium hydroxide.
CHROMATOGRAPHIC CONDITIONS
(a) Use as the coating silica gel GF254.
(b) Use the mobile phase as described below.
(c) Apply 5 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm).
MOBILE PHASE
7 volumes of 18M ammonia, 25 volumes of methanol and 68 volumes of chloroform.
LIMITS
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.5%).
ASSAY
To a volume containing 75 mg of Diazoxide add sufficient 0.1M sodium hydroxide to produce 500 mL. Dilute 5 mL to 100 mL with 0.1M sodium hydroxide and measure the absorbance of the resulting solution at the maximum at 280 nm, Appendix II B. Calculate the content of C8H7ClN2O2S taking 585 as the value of A(1%, 1 cm) at the maximum at 280 nm.
STORAGE
Diazoxide Injection should be protected from light.
