Origin

Croton oil is obtained from the seeds of Croton Tiglium, a shrub or small tree, growing in different parts of the East indies. The fruit is a three-celled capsule, with a seed in each cell. The seeds are somewhat larger than a grain of coffee, and consist of an interior oily, light, yellowish-brown kernel, and a thin black shell, covered by a soft yellowish-brown coating, which, being partially rubbed off by friction during carriage, exposes, to a greater or less extent, the black colour of the shell. The kernel is powerfully purgative in the dose of one or two grains; and the seeds themselves have long been employed in Hindostan with a view to this effect. The oil is obtained from them by expression, though it may also be separated by decoction with water, or by the action of ether, which dissolves it, and leaves it behind when evaporated. it is usually brought from India, though prepared also in England by expression.

Properties

Croton oil has an oleaginous consistency, a colour varying from pale yellow to dark reddish-brown, a peculiar odour, and a hot acrid taste, which remains long in the mouth and fauces, with unpleasant effect. There are two varieties of the oil, one pale yellow, and brought from India, the other dark reddish-brown, and prepared in England. These differ somewhat in their relations to alcohol, the latter being perfectly soluble in an equal volume of that liquid; the former, if shaken with an equal volume, forming an opaque emulsion which, upon standing, separates into two parts, the lower consisting of the oil combined with a small portion of the alcohol, the upper of alcohol diminished somewhat in bulk. This difference may possibly be owing to a change which the oil has undergone in the kernel by keeping. (Pereira, Mat. Med., 3d ed., p. 1279.) A portion of oil examined by M. Dublanc, of Paris, when agitated with alcohol, was separated into two parts, one of which, amounting to 6 per cent., was dissolved by the alcohol, the other remained undissolved, but retained 50 per cent. of the alcohol. The latter, by being repeatedly washed with alcohol, lost all its acrid property, while the other portion in alcoholic solution was extremely acrid. From this it may be inferred that the oil consists of two distinct substances, one a bland fixed oil, the other an acrid principle, held in solution by the oil, and probably the active principle as well of the oil as of the seeds. This principle appears to be volatile; for, in certain chemical processes to which the seeds were exposed by Pelletier and Caventou, a vapour was exhaled, under the application of heat, which had a strong nauseous odour and acrid taste, and irritated the eyes and nostrils. it has not, however, been isolated. The cro-tonic acid, to which the acrid property has been ascribed, has been found by Mr. Redwood to be inert, or nearly so. {ibid., p. 1274.)

Medical Effects and Uses

Croton oil is a powerful local irritant, producing, when applied to the surface, inflammation attended with a copious eruption, of which I shall have occasion to treat more particularly under the rubefacients. As a purgative, it operates with great rapidity, often in an hour or less. it is also very energetic, though in moderate doses not in general very irritating. in the character of its purgative effect, it must rank with the drastic and hydragogue cathartics; as it produces copious watery stools, and in over-doses occasions nausea, vomiting, hypercatharsis, and severe abdominal pains. Death has been produced by two drachms and a half of the oil, swallowed by mistake. in this case there was no vomiting, but excessive purging, burning pains in the oesophagus, abdominal tenderness, and great prostration, with appearances resembling those of the collapse of cholera. The patient was ill at the time of taking the oil, and was probably purged to death. No lesion was observed in the stomach. (Journ. de Chim. Med., 2e sÚr., v. 509.) There can be little doubt, I think, that the medicine produces its purgative effect by its direct irritant action on the mucous membrane. it is said sometimes to purge, when rubbed upon the anterior surface of the abdomen; but I have never witnessed this effect from the external application of the oil.

The energy and rapidity, and we may add, the comparative mildness with which it operates in ordinary doses, render croton oil a most valuable remedy in certain cases of obstinate constipation, and obstruction from accumulation in the bowels, which have resisted other cathartics. Every practitioner must have witnessed its good effects, in some of these cases. But care must be taken not to confound such cases with constipation, resulting from inflammation of the peritoneal coat of the bowels, or of their whole thickness.

In apoplexy, hemiplegia, and coma from other causes, in which the patient cannot swallow without great difficulty, the smallness of the dose renders the oil of great service; as a drop of it, placed on the back part of the tongue, and repeated if necessary, will often fulfil the indications of energetic purgation and derivation to the bowels, offered by the case.

In maniacal cases, and sometimes also in children, this smallness of the bulk answers an excellent purpose; enabling us readily to administer the oil without the knowledge of the patient, when there may be a determined resistance to all medicines.

In dropsical cases, in which purgation may be indicated, croton oil is among the hydragogues to which we can have recourse. Dr. Geo. Fife, of Birmingham, considers it among the most efficacious and safe remedies in dropsy. He gives it daily, in the dose of a minim, and thinks it acts more especially by promoting absorption; as he has not found it to possess the hydragogue properties ascribed to it. {Lancet, March, 1857, p. 259.) it has been employed in certain instances of neuralgia, and other nervous disorder, with so much success, as to have led to the supposition that it might possess a specific influence oyer the nervous system; but there is no necessity for seeking any other cause of the favourable result than the powerful revulsion from the seat of the disease to the alimentary canal.

In sciatica, it has proved highly advantageous in the hands of Mr. Hancock, of London, who believes it to act by removing from the bowels the feculent matters, which, as he thinks, produce this disorder by irritating the pelvic nerves. (Banking's Abstract, No. xxii. p. 64.)

The oil has also been recommended in obstinate amenorrhoea, and against the tapeworm.

i have found it sometimes useful, added in extremely small proportion to aloes and rhubarb, when they have begun to lose their effects on repetition. From one-twelfth to a quarter of a drop, incorporated, in the form of pill, with the ordinary laxative dose of one of these medicines, gives it sufficient activity, with but little additional irritative tendency.

Administration

The dose of croton oil is somewhat indefinite, in consequence of the different susceptibility to its operation in different individuals. There seems to be the same difference in this respect, whether the medicine is applied to the stomach or the skin; some having a remarkable insusceptibility to its action in either way. The oil, however, will generally operate in the dose of from one to three drops. The ordinary method of administration is to make two drops into four pills with the crumb of bread, and give one of these every hour till they operate. it may also be given in emulsion; but the acrid unpleasant impression it leaves in the mouth and fauces is an objection to the liquid form, when these parts have their ordinary sensibility. A tincture may be prepared by dissolving the oil in alcohol, at least so much of it as may be soluble in that liquid. An opportunity is thus afforded for a minute division of the dose. A small quantity may be readily concealed in some article of food, as in molasses, milk, cream, etc.