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].

Packaging and storage— Preserve in tight, light-resistant containers. Store at 25, excursions permitted between 15 and 30.

USP Reference standards 11— USP Physostigmine Salicylate RS.

Identification—

Specific rotation 781S: between 91 and 94.

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.

Residual solvents 467: meets the requirements.

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.

Expert Committee : (MDPP05) Monograph Development-Psychiatrics and Psychoactives

USP29–NF24 Page 1728

Phone Number : 1-301-816-8330