Packaging and storage
Preserve in well-closed containers.
Identification
Suspend about 0.1g in 10mLof water,add 0.1g of sodium carbonate,1mLof bromophenol blue TS,and 10mLof chloroform,and shake the mixture:the chloroform layer is blue.
pHá791ñ:
between 9.0and 10.5,in a dispersion of it in carbon dioxide-free water (1in 100).
Assay
Procedure
Transfer an accurately weighed portion of Topical Powder,equivalent to about 0.5mg of methylbenzethonium chloride,to a glass-stoppered,50-mLcylinder,and proceed as directed in the
Assayunder
Methylbenzethonium Chloride Lotion,beginning with Add 5mLof chloroform.