Physostigmine Salicylate
C15H21N3O2·C7H6O3 413.47

Pyrrolo[2,3-b]indol-5-ol, 1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethyl-, methylcarbamate (ester), (3aS-cis)-, mono-(2-hydroxybenzoate).
Physostigmine monosalicylate [57-64-7].
» Physostigmine Salicylate contains not less than 97.0 percent and not more than 102.0 percent of C15H21N3O2·C7H6O3, calculated on the dried basis.
Packaging and storage— Preserve in tight, light-resistant containers. Store at 25, excursions permitted between 15 and 30.
A: It responds to the Identification test under Physostigmine.
B: It responds to the tests for Salicylate 191.
Specific rotation 781S: between 91 and 94.
Test solution: 10 mg per mL, in water.
Loss on drying 731 Dry it over silica gel for 24 hours: it loses not more than 1.0% of its weight.
Residue on ignition 281: negligible, from 100 mg.
Sulfate— Precipitate the salicylic acid from 10 mL of a cold, saturated solution of Physostigmine Salicylate with a slight excess of 3 N hydrochloric acid, filter, and to the filtrate add 5 drops of barium chloride TS: no turbidity is produced immediately.
Readily carbonizable substances 271 Dissolve 100 mg in 5 mL of sulfuric acid TS: at the end of 5 minutes the solution has no more color than Matching Fluid I.
Assay— Dissolve about 250 mg of Physostigmine Salicylate, accurately weighed, in 25 mL of chloroform. Add 25 mL of glacial acetic acid, and titrate with 0.02 N perchloric acid in dioxane VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction. Each mL of 0.02 N perchloric acid is equivalent to 8.270 mg of C15H21N3O2·C7H6O3.
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Monograph Ravi Ravichandran, Ph.D.
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(MDPP05) Monograph Development-Psychiatrics and Psychoactives
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