Niclosamide Tablets
Action and use
Antihelminthic.
Definition
Niclosamide Tablets contain Niclosamide or Niclosamide Monohydrate.
Content of anhydrous niclosamide, C13H8Cl2N2O4
95.0 to 105.0% of the stated amount.
Identification
Heat a quantity of the powdered tablets containing 0.5 g of anhydrous niclosamide with 25 mL of hot ethanol (96%), filter while hot and evaporate the filtrate to dryness on a water bath. The residue complies with the following tests.
Tests
Disintegration
The requirement for Disintegration does not apply to Niclosamide Tablets.
2-Chloro-4-nitroaniline
Boil a quantity of the powdered tablets containing 0.10 g of anhydrous niclosamide with 20 mL of methanol for 2 minutes, cool, add sufficient 1m hydrochloric acid to produce 50 mL and filter. To 10 mL of the filtrate add 0.5 mL of a 0.5% w/v solution of sodium nitrite and allow to stand for 10 minutes. Add 1 mL of a 2% w/v solution of ammonium sulfamate, shake, allow to stand for 10 minutes and add 1 mL of a 0.5% w/v solution of N-(1-naphthyl)ethylenediamine dihydrochloride. Any colour produced is not more intense than that obtained by treating 20 mL of a solution in methanol containing 10 µg of 2-chloro-4-nitroaniline in the same manner and at the same time, beginning at the words ‘add sufficient 1m hydrochloric acid…’.
5-Chlorosalicylic acid
Boil a quantity of the powdered tablets containing 0.50 g of anhydrous niclosamide with 10 mL of water for 2 minutes, cool, filter and to the filtrate add 0.2 mL of iron(iii) chloride solution R1. No red or violet colour is produced.
Related substances
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
50 volumes of acetonitrile and 50 volumes of a solution containing 0.2% w/v of potassium dihydrogen orthophosphate, 0.2% w/v of tetrabutylammonium hydrogen sulfate and 0.1% w/v of disodium hydrogen orthophosphate.
In the chromatogram obtained with solution (1):
the sum of the areas of any secondary peaks is not greater than 4 times the area of the principal peak in the chromatogram obtained with solution (2) (0.2%).
Disregard any peak with an area less than the area of the principal peak in the chromatogram obtained with solution (3) (0.005%).
Assay
Weigh and powder 20 tablets. Carry out Method II for non-aqueous titration, Appendix VIII A, using a quantity of the powdered tablets containing 0.3 g of anhydrous niclosamide dissolved in 60 mL of dimethylformamide, 0.1m tetrabutylammonium hydroxide VS as titrant and determining the end point potentiometrically. Each mL of 0.1m tetrabutylammonium hydroxide VS is equivalent to 32.71 mg of C13H8Cl2N2O4.
Storage
Niclosamide Tablets should be protected from light.
Labelling
The label states that the tablets should be chewed before swallowing.
When the active ingredient is Niclosamide Monohydrate the quantity is stated in terms of the equivalent amount of anhydrous niclosamide.