Elaterium is the dried sediment from the juice of the fruit of Ecballium Elaterium, A. Richard (N.O. Cucurbitaceae), a prostrate trailing plant common in South Europe, and cultivated to a limited extent in England. The fruits are collected before they are quite ripe, sliced, and gently pressed; the juice is allowed to stand, and the deposit collected, drained, and dried. The drug occurs in light, thin, friable, flat or slightly curved opaque pieces, about 2.5 millimetres thick, pale-green in colour if fresh, becoming greyish-green on keeping. The fracture is short and granular, showing minute crystals when examined with a lens. The odour is slight, the taste bitter and acrid. The drug is sometimes adulterated with chalk or starch. It should not yield more than 10 per cent. of ash, and may yield much less. Elaterium imported from Malta is yellowish-grey in colour and contains less elaterin than the English variety.
Constituents.—The chief constituent of elaterium is the crystalline body, elaterin, of which it contains about 30 per cent. if of good quality, though the official minimum limit is fixed at 20 per cent. The drug also contains from 5 to 12 per cent. of water, about 8 per cent. of mineral matter, a small quantity of starch, fatty acids, and a phytosterol. The alleged existence in the drug of prophetin and other substances has not been confirmed. Elaterin has been shown to consist of two distinct crystalline substances: physiologically inert, laevorotatory α-elaterin, and dextrorotatory β-elaterin, which is apparently of the same percentage composition, but possesses high physiological activity. When treated for a short time with alcoholic solution of sodium hydroxide elaterin yields amorphous elateridin and acetic acid, but prolonged action of the boiling alkali solution converts the elaterin into amorphous elateric acid, oxidation of which results in the formation of a definite crystalline diketone named elaterone, C24H30O5.
Action and Uses.—Elaterium is a powerful hydragogue cathartic, and is usually administered in pills, which should be massed with milk sugar and syrup of glucose, and made to weigh 6 centigrams (1 grain) each. Sometimes elaterium is ordered in combination with other drugs, such as colocynth and hyoscyamus. Since the active principle, elaterin, is official, it should be ordered instead of the crude product, elaterium, which is liable to considerable variation in strength.
Dose.—6 to 30 milligrams (1/10 to 1/2 grain).
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.—1/2 to 2 1/2 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 (1/2 grain).
The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.