Methylbenzethonium Chloride
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Benzenemethanaminium,N,N-dimethyl-N-[2-[2-[methyl-4-(1,1,3,3-tetramethylbutyl)phenoxy]ethoxy]ethyl]-,chloride,monohydrate.
Benzyldimethyl[2-[2-[[4-(1,1,3,3-tetramethylbutyl)tolyl]oxy]ethoxy]ethyl]ammonium chloride monohydrate [1320-44-1].
Anhydrous 462.12 [25155-18-4].
»Methylbenzethonium Chloride contains not less than 97.0percent and not more than 103.0percent of C28H44ClNO2,calculated on the dried basis.
Packaging and storage—
Preserve in tight containers.
Identification—
A:
To 1mLof a solution (1in 100)add 2mLof alcohol,0.5mLof 2Nnitric acid,and 1mLof silver nitrate TS:a white precipitate,which is insoluble in 2Nnitric acid and soluble in 6Nammonium hydroxide,is formed.
B:
Treat separate portions of a solution (1in 100)with 2Nnitric acid and with mercuric chloride TS,respectively:precipitates are formed that dissolve upon the addition of alcohol.
C:
To 10mLof a solution (1in 20,000)add 0.1g of sodium carbonate,1mLof bromophenol blue TS,and 10mLof chloroform,and shake the mixture:the chloroform layer is blue.
D:
Dissolve 100mg in 1mLof sulfuric acid,add 1.0g of potassium nitrate,and heat on a steam bath for 3minutes.Cautiously dilute the solution with water to 10mL,add 0.5g of granulated zinc,and warm the mixture for 10minutes.Cool,add 0.2g of sodium nitrite to 1mLof the clear liquid,and add this mixture to 20mg of naphthol dipotassium disulfonate or naphthol disodium disulfonate in 1mLof ammonium hydroxide:the solution turns orange-red,and a brown precipitate may be formed.
Loss on drying á731ñ—
Dry it at 105
for 4hours:it loses not more than 5.0%of its weight.
for 4hours:it loses not more than 5.0%of its weight.
Residue on ignition á281ñ:
not more than 0.1%.
Limit of ammonium compounds—
To 5mLof a solution (1in 50)add 3mLof 1Nsodium hydroxide,and heat to boiling:the odor of ammonia is not perceptible.
Assay—
Accurately weigh a quantity of Methylbenzethonium Chloride,equivalent to about 500mg of dried methylbenzethonium chloride,and transfer,with the aid of 35mLof water,to a glass-stoppered,250-mLconical separator containing 25mLof chloroform.Add 10.0mLof freshly prepared potassium iodide solution (1in 20),insert the stopper in the separator,shake,allow the layers to separate,and discard the chloroform layer.Wash the aqueous layer with three 10-mLportions of chloroform,and discard the washings.Transfer the aqueous layer to a glass-stoppered,250-mLconical flask,and rinse the separator with three 5-mLportions of water,adding the washings to the flask.Add 40mLof cold hydrochloric acid to the flask,mix,and titrate with 0.05Mpotassium iodate VSuntil the solution becomes light brown in color.Add 5mLof chloroform,insert the stopper in the flask,and shake vigorously.Continue the titration,dropwise,with shaking after each addition,until the chloroform layer becomes colorless and the aqueous layer is clear yellow.Perform a blank determination,using 20mLof water as the test specimen (see Residual Titrationsunder Titrimetry á541ñ).Each mLof 0.05Mpotassium iodate is equivalent to 46.21mg of C28H44ClNO2.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1256
Pharmacopeial Forum:Volume No.27(1)Page 1802
Phone Number:1-301-816-8394