C6H8N4O4 200.2 7681-76-7
Action and use
Antiprotozoal.
DEFINITION
Ronidazole is (1-methyl-5-nitroimidazol-2-yl)methyl carbamate. It contains not less than 98.5% and not more than 101.0% of C6H8N4O4, calculated with reference to the anhydrous substance.
CHARACTERISTICS
A white to yellowish brown powder; odourless or almost odourless.
Slightly soluble in water, in chloroform and in ethanol (96%); very slightly soluble in ether.
IDENTIFICATION
A. The infrared absorption spectrum, Appendix II A, is concordant with the reference spectrum of ronidazole (RSV 36).
B. The light absorption, Appendix II B, in the range 230 to 350 nm of a 0.002% w/v solution in 0.1M methanolic hydrochloric acid exhibits a maximum only at 270 nm. The absorbance at the maximum is about 0.64.
C. Melting point, about 167°, Appendix V A.
TESTS
Colour of solution
A 0.5% w/v solution in methanol is not more intensely coloured than reference solution Y6, Appendix IV B, Method II.
(1-Methyl-5-nitroimidazol-2-yl)methanol
Carry out the method for thin-layer chromatography, Appendix III A, using silica gel GF254 as the coating substance and a mixture of 5 volumes of glacial acetic acid, 5 volumes of methanol and 80 volumes of toluene as the mobile phase. Apply
Ronidazole separately to the plate 20 μL of each of two solutions in acetone containing (1) 1.0% w/v of the substance being examined and (2) 0.0050% w/v of (1-methyl-5-nitroimidazol-2-yl)methanol BPCRS. After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm). Any spot in the chromatogram obtained with solution (1) corresponding to (1- methyl-5-nitroimidazol-2-yl)methanol is not more intense than the spot in the chromatogram obtained with solution (2) (0.5%).
Water
Not more than 0.5% w/w, Appendix IX C. Use 5 g.
Sulfated ash
Not more than 0.1%, Appendix IX A.
ASSAY
Carry out Method I for non-aqueous titration, Appendix VIII A, using 0.3 g and determining the end point potentiometrically. Each mL of 0.1M perchloric acid VS is equivalent to 20.02 mg C6H8N4O4.
STORAGE
Ronidazole should be protected from light.
