ICHTHYOL. — Ichthyol (ammonium ichthyol-sulphonate) is a distillation product prepared from a bituminous mineral, found in the Tyrol, which is rich in fossilized remains of fish and sea animals, whence the name "ichthyol" (ixOt"z, fish). By dry distillation of this bituminous mineral a crude volatile oil is obtained which, at a temperature of 212° F., is treated with an excess of con centrated sulphuric acid, forming ich thyol-sulphonic acid. This latter sub stance unites with the alkaline bases (am monia, soda, lithia, etc.) and forms ich thyol-salts, of which the principal ones are ammonium ichthyol-sulphonate (or ichthyol-ammonium) and sodium ich thyol-sulphonate (or ichthyol-sodium), the former being always understood when the term ichthyol is used alone. These substances are rich in sulphur (about 15 per cent.), which is combined partly with oxygen, partly with carbon, in a condi tion similar to that in mercaptans and organic sulphides (Baumann). Ichthyol has a reddish-brown color and a bitumin ous taste and odor. The sodium salt is semisolid (the consistency of a solid ex tract), and the ammonium-salt is a thick, brown liquid of the consistency of syrup. Ichthyol is readily soluble in water and in a mixture of equal parts of alcohol and ether; it mixes well with lanolin, vaselin, glycerin, fats, and oils, and with collodion and traumaticin.
Preparation and Dose.—Ammonium ichthyol-sulphonate, 3 to 20 minims.
Lithium ichthyol-sulphonate, 3 to 10 grains.
Sodium ichthyol-sulphonate, 3 to 10 grains.
Zinc ichthyol-sulphonate. Hydrargyrum ichthyol-sulphonate. Physiological Action.—Ichthyol has antiphlogistic, anodyne, alterative, anti pruritic, antiseptic, and astringent prop erties. Its peculiar virtues are largely ascribed to the large amount of sulphur it contains.
When administered internally, al though having a peculiar odor, it excites no nausea. In medicinal doses it is be lieved that it retards the disintegration of albuminoid substances and favors their formation and assimilation (Zuel zer, Charles). In larger doses it increases
peristalsis and has a laxative action on the bowels. Helmers has found that a third of the sulphur contained in the drug is eliminated by the urine, while the remaining elements pass out in the feces. He also finds that the sulphur of the ichthyol takes at least seven days to be completely removed from the or ganism; hence he concludes that ich thyol is not simply passed through with the food-excretions, but is first absorbed into the system and then again secreted.
When applied locally, it acts as a re ducing agent (abstracts oxygen from the tissues) and exerts a peculiar contractile effect upon the vascular tissues; hence the application of ichthyol is followed by a diminution of heat, a reduction of swelling, a paling of the tissues, and a relief of pain Moreover, the drug undoubtedly inhibits bacterial de velopment, as proved by the experiments of Fessler and Klein.
Ichthyol is absorbed by the normal skin of the dog; an evidence of the ab sorption is afforded by the increase of sulphur in the urine. The skin appears to be penetrable to such substances as arc readily soluble in water and in fat, whereby these substances are enabled not only to act upon the deeper cutaneous layers, but are also able to exert effects in distant parts of the body. Cornelius Beck and Bela von Fenyvessy (Archly internat. de Pharm. et de Therap., vi, Nos. 1 and 2, '99).
Injected subcutaneously, ichthyol lowers the rectal temperature for about an hour (Dujardin-Beaumetz).
Therapeutics.—Ichthyol is not only peculiar in its origin, but in that it pos sesses so many widely-different thera peutic properties. We would naturally infer that its use would be indicated in a large variety of ailments and disorders. This we find to be true. Although not a panacea, it has established itself as one of the most valuable therapeutic aids at our command.
Ichthyol can be used pure or dissolved in any of the usual solvents.