Extractum Physostigmatis (U. S. P.)—Extract of Physostigma.
Related entry: Physostigma (U. S. P.)—Physostigma
SYNONYM: Extract of calabar bean.
Preparation.—"Physostigma, in No. 80 powder, one thousand grammes (1000 Gm.) 12 lbs. av., 3 ozs., 120 grs.]; alcohol, a sufficient quantity. Moisten the powder with four hundred cubic centimeters (400 Cc.) [13 fl℥, 252♏] of alcohol, and pack it firmly in a cylindrical percolator; then add enough alcohol to saturate the powder and leave a stratum above it. When the liquid begins to drop from the percolator, close the lower orifice, and, having closely covered the percolator, macerate for 48 hours. Then allow the percolation to proceed, gradually adding alcohol until three thousand cubic centimeters (3000 Cc.) [101 fl℥, 212♏] of tincture are obtained, or the Physostigma is exhausted. Reserve the first nine hundred cubic centimeters (900 Cc.) [30 fl℥, 208♏] of the percolate, and evaporate the remainder, at a temperature not exceeding 50° C. (122° F.), to one hundred cubic centimeters (100 Cc.) [3 fl℥, 183♏]; mix this with the reserved portion, and evaporate, at or below the before-mentioned temperature, on a water-bath, to a pilular consistence"—(U. S. P.).
Description, Medical Uses, and Dosage.—(See Physostigma). In the preparation of this extract, the menstruum directed in the official process should be strictly adhered to. Diluted alcohol produces a greater yield of extract, but at its alkaloidal expense. Extract of Physostigma well represents calabar bean, and is of a green-brown color. Dose, 1/16 to 1/8 grain.