Elaterinum (U. S. P.)—Elaterin.
FORMULA: C20H28O5. MOLECULAR WEIGHT: 347.20.
"A neutral principle obtained from elaterium, a substance deposited by the juice of the fruit of Ecballium Elaterium (Linné), A. Richard (Nat. Ord.—Cucurbitaceae)"—(U. S. P.).
Preparation.—Elaterinum is the principle on which the active properties of elaterium depend. It was first obtained by Morries. Hennel procured it by separating the green resin (chlorophyll) from the crystalline matter of the alcoholic extract of elaterium (see Elaterium), by ether, which took up the resin and left the elaterin. The latter was then purified by solution in hot alcohol and subsequent crystallization.
According to Flückiger (Pharmacographia), the best method of obtaining elaterin is to exhaust elaterium by means of chloroform; treat the solution so obtained with ether, upon which white crystals of elaterin at once separate. Wash with a small quantity of ether, and recrystallize the pure elaterin from chloroform. This process has been adopted by the British Pharmacopoeia. Good elaterium should yield from 20 to 25 per cent of elaterin. Less is obtained as the fruit approaches maturity. As high as 50 per cent has been isolated (Walz).
Description and Tests.—Pure elaterin, as officially described, occurs in "minute, white, hexagonal scales, or prismatic crystals, without odor, and having a slightly acrid, bitter taste; permanent in the air. Soluble, at 15° C. (59° F.), in 4250 parts of water, and in 337 parts of alcohol; in 1820 parts of boiling water, and in 34 parts of boiling alcohol; also soluble in 543 parts of ether, or in 2.4 parts of chloroform. At 190° C. (374° F.) the crystals begin to agglutinate, and at about 209° C. (408.2° F.) they melt, forming a yellowish-brown liquid. When ignited, they are consumed without leaving a residue. Elaterin is neutral to litmus paper. Elaterin is dissolved by solutions of the alkalies, and reprecipitated on supersaturating with an acid. When dissolved in cold, concentrated sulphuric acid, it causes the latter to become yellow at first, which color gradually changes to scarlet. On dissolving some crystals of elaterin in melted carbolic acid, and then adding a few drops of strong sulphuric acid, a crimson color will be developed, which soon becomes scarlet. An alcoholic solution of elaterin should not be precipitated by tannic acid T.S., mercuric chloride T.S., or platinic chloride T.S. (absence of, and difference from, alkaloids)"—(U. S. P.). Elaterin is possessed of all the activity of elaterium, being considerably stronger and always more definite in strength and quality. Its alcoholic solution is. the most active preparation.
Action, Medical Uses, and Dosage.—(See Elaterium.) The dose of elaterin is from 1/40 to ⅛ grain, the latter being a rather large dose. Not more than 1/20 to 1/25 grain should be administered as a beginning dose.