Benztropine Mesylate

(benz' troe peen mes' i late).

C21H25NO·CH4O3S

403.54

8-Azabicyclo[3.2].1octane, 3-(diphenylmethoxy)-, endo-, methanesulfonate.

-(Diphenylmethoxy)-1

h,5

h-tropane methanesulfonate

[132-17-2].

» Benztropine Mesylate contains not less than 98.0 percent and not more than 100.5 percent of C21H25NO·CH4O3S, calculated on the dried basis.

Packaging and storage— Preserve in tight containers.

USP Reference standards

—

USP Benztropine Mesylate RS

Identification, Infrared Absorption

197K

Melting range

741

: between 141

and 148

Loss on drying

731

— Dry it at 105

for 2 hours: it loses not more than 5.0% of its weight.

Residue on ignition

281

: not more than 0.1%.

Assay— Transfer about 60 mg of Benztropine Mesylate, accurately weighed, to a 125-mL separator. Dissolve in 25 mL of water, add 5 mL of sodium carbonate TS, and extract with four 10-mL portions of chloroform. Wash the combined chloroform extracts with about 10 mL of water, and extract the wash solution with 5 mL of chloroform. Filter the combined chloroform extracts through a tightly packed pledget of cotton, and wash the cotton with about 5 mL of chloroform. Add methyl red TS, and titrate the chloroform solution with 0.01 N perchloric acid in dioxane VS. Perform a blank determination, and make any necessary correction. Each mL of 0.01 N perchloric acid is equivalent to 4.035 mg of C21H25NO·CH4O3S.

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question	Contact	Expert Committee
Monograph	Ravi Ravichandran, Ph.D. Principal Scientific Liaison 1-301-816-8330	(SM42010) Monographs - Small Molecules 4
Reference Standards	RS Technical Services 1-301-816-8129 rstech@usp.org

USP35–NF30 Page 2330

Pharmacopeial Forum: Volume No. 29(6) Page 1848