Procainamide Injection
Action and use
Class I antiarrhythmic.
Definition
Procainamide Injection is a sterile solution of Procainamide Hydrochloride in Water for Injections.
Content of procainamide hydrochloride, C13H21N3O,HCl
95.0 to 105.0% of the stated amount.
Characteristics
A colourless or almost colourless solution.
Identification
Tests
Acidity
pH, 4.0 to 5.5, Appendix V L.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions in methanol.
0.7 volumes of 13.5m ammonia, 30 volumes of methanol and 70 volumes of chloroform.
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
To a volume containing 0.5 g of Procainamide Hydrochloride add 45 mL of 6m hydrochloric acid and boil for 1 minute. Cool and titrate with 0.1m sodium nitrite VS, using 1 mL of ferrocyphen solution as indicator, until a violet colour is produced that is stable for not less than 3 minutes. Repeat the operation without the injection. The difference between the titrations represents the amount of sodium nitrite required. Each mL of 0.1m sodium nitrite VS is equivalent to 27.18 mg of C13H21N3O,HCl.