Benzethonium Chloride
448.08Benzenemethanaminium, N,N-dimethyl-N-[2-[2-[4-(1,1,3,3-tetramethylbutyl)phenoxy]ethoxy]ethyl]-, chloride.
Benzyldimethyl[2-[2-[p-(1,1,3,3-tetramethylbutyl)phenoxy]ethoxy]ethyl]ammonium chloride
[121-54-0].» Benzethonium Chloride contains not less than 97.0 percent and not more than 103.0 percent of C27H42ClNO2, calculated on the dried basis.
Packaging and storage—
Preserve in tight, light-resistant containers.
Identification—
A:
To 1 mL of a solution (1 in 100) add 2 mL of alcohol, 0.5 mL of 2 N nitric acid, and 1 mL of silver nitrate TS: a white precipitate, which is insoluble in 2 N nitric acid but soluble in 6 N ammonium hydroxide, is formed.
B:
A solution (1 in 100) forms precipitates with 2 N nitric acid and with mercuric chloride TS, both of which dissolve upon the addition of alcohol.
C:
Dissolve 0.1 g in 1 mL of sulfuric acid, add 0.1 g of potassium nitrate, and heat on a steam bath for 3 minutes. Cautiously dilute the solution with water to 10 mL, add 0.5 g of granulated zinc, and warm the mixture for 10 minutes. Cool, add 0.2 g of sodium nitrite to 1 mL of the clear liquid, and add this mixture to 20 mg of naphthol dipotassium disulfonate or naphthol disodium disulfonate in 1 mL of ammonium hydroxide: the solution turns orange-red, and a brown precipitate may be formed.
Loss on drying 
731
—
Dry it at 105
for 4 hours: it loses not more than 5.0% of its weight.
731—
Dry it at 105 for 4 hours: it loses not more than 5.0% of its weight.
Residue on ignition 281:
not more than 0.1%.
281:
not more than 0.1%.
Limit of ammonium compounds—
To 5 mL of a solution (1 in 50) add 3 mL of 1 N sodium hydroxide, and heat to boiling: the odor of ammonia is not perceptible.
Assay—
Dissolve about 0.3 g of Benzethonium Chloride, accurately weighed, in 75 mL of water contained in a glass-stoppered, 250-mL flask. Add 0.4 mL of bromophenol blue solution (1 in 2000), 10 mL of chloroform, and 1 mL of 1 N sodium hydroxide. Titrate with 0.02 M sodium tetraphenylboron VS until the blue color disappears from the chloroform layer. Add the last portions of the sodium tetraphenylboron solution dropwise, agitating vigorously after each addition. Each mL of 0.02 M sodium tetraphenylboron is equivalent to 8.962 mg of C27H42ClNO2.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
| Monograph | Behnam Davani, Ph.D., M.B.A.
Senior Scientist 1-301-816-8394 |
(MDAA05) Monograph Development-Antivirals and Antimicrobials |
USP32–NF27 Page 1638
Pharmacopeial Forum: Volume No. 27(1) Page 1754