Methylbenzethonium Chloride Ointment
» Methylbenzethonium Chloride Ointment contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of methylbenzethonium chloride (C28H44ClNO2·H2O).
Packaging and storage— Preserve in collapsible tubes or in tight containers.
Identification— Suspend about 0.5 g of Ointment 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 chloroform layer is blue.
pH 791: between 5.0 and 7.0, in a dispersion of it in carbon dioxide-free water (1 in 100).
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 Ointment, 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.”
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
(MDAA05) Monograph Development-Antivirals and Antimicrobials
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 2938