Cevadilla. Sabadilla; Veratrina. Veratrine.
Sabadilla consists of the dried ripe seeds of Schoenocaulon officinale, A. Gray (N.O. Liliaceae), a tall herbaceous plant growing on the low mountain slopes in Mexico, Guatemala, and Venezuela. The seeds are usually imported freed from the thin brown papery pericarp. The seeds are of a glossy, dark brown, almost black colour, about 6 millimetres or more in length, but not more than 2 millimetres wide. They are acutely pointed at one extremity, but more obtuse at the other, where both hilum and micropyle are situated, although they cannot be easily discerned. On one side of the seed there is usually a depression with sharp edges due to the mutual pressure of the seeds upon one another in the fruit, which is also slightly curved. The seeds are odourless, but have an unpleasant, bitter, acrid taste; the powder is a powerful sternutatory.
Constituents.—Sabadilla contains several alkaloids, of which cevadine (crystalline veratrine) is the most important. Cevadine, C32H49NO9, occurs in colourless crystals melting at 205°, which have a very powerful sternutatory effect; it is easily hydrolysed by alkalies, yielding cevedine (cevine) and methyl-crotonic acid. Cevadine is accompanied in sabadilla seeds by the alkaloids veratridine, sabadilline (cevadilline), sabadine, sabadinine, and sabatrine, the latter being said to be a mixture. Sabadilla seeds also contain cevadic and veratric acids, fatty oil, resin, etc. Veratridine is amorphous and yields by hydrolysis veratric acid and veratroine (verine); like cevadine it has a powerful sternutatory effect. Much confusion has existed in the nomenclature of the alkaloids of cevadilla. The crystalline alkaloid cevadine has been termed veratrine; the amorphous alkaloid veratridine has also been termed veratrine, while the British Pharmacopoeia applies the name veratrine to an indefinite mixture of cevadine and veratridine. Hence it is advisable to discard the name veratrine for any particular alkaloid.
Action and Uses.—Sabadilla is of importance chiefly as the source of the mixture of alkaloids, which is official under the name of veratrine. In powder, and in the form of Acetum Cevadillae, it has been used as a parasiticide.
- Acetum Cevadillae, B.P.C.—VINEGAR OF SABADILLA. 1 in 10.
- Used as a parasiticide, especially for pediculi capitis.
Veratrine, so-called, is a mixture of alkaloids, of variable composition, obtained from sabadilla, the dried ripe seeds of Schoenocaulon officinale, A. Gray (N.O. Liliaceae), by exhausting the powdered seeds with alcohol. It is also official in the U.S.P. Veratrine occurs in the form of white or greyish-white, pulverulent masses, which are amorphous, odourless, and have a very persistent bitter and intensely acrid taste, followed by a sensation of numbness. The powder causes intense irritation of the nasal mucous membrane, and excites violent sneezing. Slightly hygroscopic in moist air. The alcoholic solution is alkaline to litmus. Its melting-point is ill-defined, and lies somewhere between 145° and 155°.
Almost insoluble in water; soluble in boiling water (1 in 1000), alcohol (1 in 3), ether (1 in 6), chloroform (1 in 3), olive oil (about 1 in 80), sparingly in glycerin; freely in diluted acids, but leaving slight traces of an insoluble, brown, resinous body; very soluble in benzene and in amyl alcohol, insoluble in petroleum benzin.
Constituents.—The mixed alkaloids consist chiefly of cevadine (veratrine), veratridine, sabadilline (cevadilline), sabadine, sabadinine, and sabatine, which is probably not a definite substance. Cevadine, C32H49NO9, is a crystalline alkaloid which may be decomposed by heating with alcoholic potash into methyl-crotonic acid (tiglic or cevedic acid), C5H8O2, and an amorphous base, cevedine (cevine); veratridine, C27H53NO11, is amorphous, and may similarly be decomposed into dimethyl-protocatechuic acid (veratric acid), C9H10O4, and an amorphous base, verine (veratroine), probably identical with cevine; sabadilline (cevadilline) is an amorphous base, C34H53NO8; sabadine, C29H51NO8, and sabadinine, are both crystalline bodies.
Action and Uses.—Veratrine resembles aconitine in its action on the peripheral nerve-endings; applied externally it gives rise to tingling, followed by numbness and coldness, which may be followed by some irritation. Veratrine exerts a characteristic stimulant direct action on all forms of muscle tissue, which is shown in the case of plain muscle by colic-like spasms of the intestine, exaggeration of the movements of the uterus, bladder, bronchioles, etc., and intense vaso-constriction. The vaso-constriction differs from that caused by adrenine in that it affects also the pulmonary, coronary, and cerebral vessels. The heart is first slowed to a slight extent and then quickened, the strength of systole being increased. Veratrine increases the irritability of striped muscle so as to increase the work it is capable of doing. In large doses the muscle -Contraction is prolonged, relaxation being long drawn out. Veratrine is rarely used internally. It is applied in the form of ointment or as Oleinatum Veratrinae for its analgesic properties in neuralgia, especially facial neuralgia, but must not be used where the skin is broken. In cases of poisoning by veratrine the stomach tube should be used or an emetic administered. Stimulants and strong coffee should be given, and the recumbent position maintained.
Dose.—1 to 4 milligrams (1/70 to 1/16 grain).
- Oleatum Veratrinae, U.S.P.—Same as Oleinatum Veratrinae, B.P.C.
- Oleinatum Veratrinae, B.P.C.—OLEINATE OF VERATRINE. Syn.—Oleatum Veratrinae; Oleate of Veratrine. 1 in 50.
- Applied with a brush to allay pain in neuralgia; it is readily absorbed.
- Unguentum Veratrinae, B.P.—VERATRINE OINTMENT.
- Veratrine, 2; oleic acid, by weight, 8; lard, 90. Mix the veratrine with the oleic acid, warm gently until dissolved, and incorporate the lard. Veratrine ointment is applied as an anodyne in facial neuralgia. It first stimulates the sensory nerve endings, and later depresses them. It must not be used where the skin is broken.
- Unguentum Veratrinae, U.S.P.—VERATRINE OINTMENT, U.S.P.
- Veratrine, 4; almond oil, 6; benzoinated lard, 90.