Santoninum, B.P., Santonin.

Related entry: Santonica - Butea Seeds

C₁₅H₁₈O₃ = 246.144

Santonin, C₁₅H₁₈O₃, is a crystalline bitter lactone prepared from santonica, the dried, unexpanded flower heads or capitula of Artemisia maritima, var. Stechmanniana, Besser. Santonin may be obtained by mixing santonica with milk of time, converting the time salt into a soluble sodium salt and decomposing the latter with sulphuric acid. From the acid liquid santonin crystallises oil cooling. Traces of acid may be removed by washing with water to which a little ammonia has been added. Santonin is also official in the U.S.P. It occurs in colourless, shining, flat, rhombic prisms, without odour, and almost tasteless at first, but afterwards developing a bitter taste. Melting-point, 170°; it sublimes on further careful heating. Exposure to daylight causes it to assume a yellow colour (chromo-santonin). This discoloured santonin yields a yellow alcoholic solution, from which the santonin may be recovered in a colourless state by concentration. Alkaline solutions convert it into santonates, from which santonic acid may be obtained by shaking with hydrochloric acid and ether. If a few crystals of santonin be warmed with 2 or 3 mils of solution of ethyl nitrite and a few drops of solution of potassium hydroxide are added, a fine, rose-red colour is produced. When moistened with concentrated sulphuric acid not more than a slightly yellow colour should be developed. If santonin be boiled with water acidified with sulphuric acid, frequently shaken, and then filtered, the filtrate when cold should produce no turbidity on the addition of potassio-mercuric iodide (absence of alkaloids).

Sparingly soluble in water, more soluble in boiling water; soluble in alcohol (1 in 40), boiling alcohol (1 in 3), chloroform (1 in 4), ether (1 in 140). The solutions are neutral to litmus and are laevogyrate. Soluble in solutions of caustic alkalies; insoluble in dilute mineral acids.

Action and Uses.—Santonin is used as a remedy for round worms. Its action appears not to be that of a direct poison to the parasites, as they are expelled alive; it probably causes the worms to migrate to the lower gut, either through some disagreeable property of the drug, or by lowering the vitality of the worm so that it no longer resists peristaltic movements. In either case the parasites are removed by the purge—usually castor oil—which is best given twelve hours after the dose of santonin. It is also used to expel thread worms, but has no action on the tape worm. Santonin is absorbed to a greater or less extent, giving rise to specific effects on the sense organs, especially the colour sense, and central nervous system. Appreciation of colour is disturbed, and illuminated objects appear to have a yellowish tinge, which is sometimes preceded by a faint blue colour. Santonin may also cause headache, nausea, and vomiting, or, in large doses, epileptiform convulsions. The absorbed santonin renders the urine an intense yellow colour, if acid, or purplish, if alkaline. Santonin is usually administered as a powder, one dose each night for three nights, followed each morning by a dose of castor oil. It may also be suspended in a mixture with compound powder of tragacanth, or given as Trochiscus Santonini. Santonin should not be given in solution, as this facilitates absorption. It is often given with calomel or compound powder of scammony. Suppositories of santonin (3 grains in each) are used for thread worms. Santonin rendered yellow by exposure to direct sunlight is sometimes preferred. It is known as "yellow santonin" or "photosantonin," and has been specially recommended in tropical sprite and dysentery in doses of 3 decigrams (5 grains). It is stated to be less poisonous than santonin.

Dose.—1 to 3 decigrams (2 to 5 grains).

PREPARATIONS.

Tablettae Santonini Compositae, B.P.C.—COMPOUND SANTONIN TABLETS.

Each tablet contains santonin, 1 grain, and mercurous chloride, 1 grain. Used to expel round and thread worms in children. Calomel assists the action of santonin. Dose.—1 or 2 tablets

Trochiscus Santonini, B.P.—SANTONIN LOZENGE.

Each lozenge contains santonin, 1 grain; with simple basis. Santonin lozenges are given to children to expel round worms and thread worms. They should be followed by a dose of castor oil.

Trochisci Santonini, U.S.P.—TROCHES OF SANTONIN.

Santonin, 3 grammes; sugar, 90 grammes; tragacanth, 3 grammes; undiluted orange-flower water, a sufficient quantity. To make 100 troches.

The British Pharmaceutical Codex, 1911, was published by direction of the Council of the Pharmaceutical Society of Great Britain.