Methylbenzethonium Chloride Topical Powder
» Methylbenzethonium Chloride Topical Powder contains not less than 85.0 percent and not more than 115.0 percent of the labeled amount of methylbenzethonium chloride (C28H44ClNO2·H2O) in a suitable fine powder base, free from grittiness.
Packaging and storage— Preserve in well-closed containers.
Identification— Suspend about 0.1 g in 10 mL of water, add 0.1 g of sodium carbonate, 1 mL of bromophenol blue TS, and 10 mL of chloroform, and shake the mixture: the chloroform layer is blue.
pH 791: between 9.0 and 10.5, in a dispersion of it in carbon dioxide-free water (1 in 100).
Other tests— Not less than 99% of it passes through a No. 200 sieve (see Powder Fineness 811).
0.0001 N Docusate sodium— Prepare as directed for 0.0001 N Docusate sodium in the Assay under Methylbenzethonium Chloride Lotion.
Procedure— Transfer an accurately weighed portion of Topical Powder, equivalent to about 0.5 mg of methylbenzethonium chloride, to a glass-stoppered, 50-mL cylinder, and proceed as directed in the Assay under Methylbenzethonium Chloride Lotion, beginning with “Add 5 mL of chloroform.”
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Topic/Question Contact Expert Committee
Monograph Behnam Davani, Ph.D., M.B.A.
Senior Scientist
(MDAA05) Monograph Development-Antivirals and Antimicrobials
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 2938
Pharmacopeial Forum: Volume No. 30(2) Page 516