Active Ingredients. - Croton oil, as expressed from the seeds of the croton tiglium, and employed in medicine, is a clear, darkish-brown, rather thick fluid, and contains, according to Schlippe,1 4 per cent. of a substance which he calls crotonol, and on which the irritant action of the drug on the skin appears to depend. It is a colorless or pale-yellow turpentine-like substance, with a faint but characteristic odor; it is destroyed by heat; and the action of caustic potash changes it to a brownish resinoid mass. This, however, is not the purgative principle of croton oil, for Schlippe could not produce either diarrhoea or intestinal inflammation when he administered as much as 1 1/2 grain to rabbits. The oil also contains fixed fatty acids, and two volatile ones; angelicic acid, C5H8O2, and crotonic acid, C4H6O2. Neither of these acids appears to be purgative, and the latest researches render it probable that the drastic principle is only secondarily developed from a saponification process within the alimentary canal, which produces a resinoid body.2

Physiological Action. - Croton oil possesses both a local and a remote action; the former is well displayed in its effects upon the skin, which, as already remarked, are due to the crotonol. The result of croton-oil frictions is the speedy production of redness, and a copious pustular rash, attended by great irritation and pain. Given internally, it produces the drastic purgation which is valued in medical practice, and, in large doses, causes also violent vomiting, collapse, and death; the general symptoms much resembling those of Asiatic cholera. If the patient survives a large dose, he suffers from gastro-enteritis.

These poisonous effects have been produced, not merely by the oil, but also by the accidental eating of the seeds. The inhalation of the dust by those who handle large quantities of the seeds has likewise caused epigastric pain, soreness of the eyes, and swelling of the face; and in one recorded case has even proved fatal.

1 Ann. Chera. Pharm., cv. 1. 2 Buchheim.

Therapeutic Action. - Croton oil is valuable only for a limited class of cases, in which it is desired to produce a speedy drastic purgation, combined with considerable vascular depression. In general, the action is speedy, and, compared with those of other powerful drastics, the effects are not so distressing to the patient. At the same time, it must be remarked that there is some uncertainty in the operation, for occasionally even 6, 8, or 10 drops fail to produce the desired effect.

Preparations And Dose. - Croton oil is administered simply in pill (with conserve of roses, or gum and sugar), or it is mixed up with powdered sugar, and placed upon the tongue, as when the patient is insensible, in apoplexy, etc. Dose, 1/2 to 1 minim of the oil, repeated as required. For external use there is the liniment (B. Ph.), made with one part of croton to seven parts of olive oil.