甲硝唑片 BP2003.doc

甲硝唑片 BP2003
Metronidazole Tablets
Definition
Metronidazole Tablets contain Metronidazole.
With the exception of the requirements for shape, the ply with the requirements stated under Tablets and with the following requirements.
Content of metronidazole, C6H9N3O3
to % of the stated amount.
Identification
A. Shake a quantity of the powdered tablets containing g of Metronidazole with 40 ml of chloroform for 15 minutes, filter and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of metronidazole (RS 229).
B. Shake a quantity of the powdered tablets containing g of Metronidazole with 4 ml of sulphuric acid and filter. To the filtrate add 10 ml of picric acid solution R1 and allow to stand. The melting point of the precipitate, after washing with water and drying at 105°, is about 150°, Appendix V A.
C. Heat a quantity of the powdered tablets containing 10 mg of
Metronidazole on a water bath with 10 mg of zinc powder , 1 ml of water and ml of hydrochloric acid for 5 minutes, cool in ice, add ml of sodium nitrite solution and remove the excess of nitrite with sulphamic acid. Add ml of 2-naphthol solution and 2 ml of 5M sodium hydroxide. An orange-red colour is produced.
Related substances
Carry out the method for liquid chromatograph