Elaterinum, B.P. Elaterin.
Related entry: Elaterium
C28H38O7 = 486.304.
Elaterin, C29H38O7, or Momordicin, is a mixture of crystalline substances—α-elaterin and β-elaterin—obtained from elaterium by boiling the latter with alcohol, precipitating the resulting solution by water, and purifying the precipitate by washing with ether and recrystallising from absolute alcohol; or by extracting with chloroform, evaporating, washing the residue with ether, and recrystallising from alcohol or chloroform. The product contains from 60 to 80 per cent. of inert α-elaterin. It is also official in the U.S.P. Elaterin occurs in the form of small hexagonal scales or prismatic crystals, or as a white crystalline powder; neutral, odourless, and having a slightly acrid, bitter taste. On being heated it first becomes yellow, then melts at 209°, forming a yellow-brown liquid; and on complete ignition it burns without leaving any residue. Sulphuric acid colours it yellow, gradually changing to scarlet; concentrated sulphuric acid with a trace of potassium bichromate produces an olive-green colouration, which gradually becomes darker.
Insoluble in water, or glycerin; difficultly soluble in cold alcohol (1 in 160), benzol, or ether; easily soluble in chloroform, carbon bisulphide, amyl alcohol, and hot alcohol. It is soluble in solutions of alkalies and re-precipitated from these by excess of acid.
Action and Uses.—Elaterin must be carefully distinguished from the drug elaterium. It is usually prescribed as Pulvis Elaterini Compositus, which is best administered in a pill with extract of henbane. Elaterin is a most powerful hydragogue cathartic, and should be used with great caution, as its action is frequently followed by prostration. It does not appear to be absorbed. It is used chiefly in cardiac or renal disease, accompanied by dropsy.
Dose.—2 to 6 milligrams ( 1/40 to 1/10 grain).
- Pulvis Elaterini Compositus, B.P.—COMPOUND POWDER OF ELATERIN.
- Elaterin, in fine powder, 1; milk sugar, in fine powder, 39. This preparation is a drastic hydragogue cathartic, and should be used with caution. Dose.—½ to 2 ½ decigrams (1 to 4 grains).
- Trituratio Elaterini U.S.P.—TRITURATION OF ELATERIN.
- Elaterin, 10; milk sugar, in moderately fine powder, 90. Average dose.—30 milligrams (½ grain).