Definition. - Tetraiodopyrrol, a derivative of the base pyrrol (C4H5N), obtained by the direct action of iodine upon the base in the presence of alcohol.

Description and Properties. - A light, grayish-brown, crystalline powder without odor or taste. Very slightly soluble in water (1:4900), much more so in alcohol (1: 9), soluble in fixed oils.

Dose. - Average dose: 0.250 Gm. =250 milligrammes (4 grains, U. S. P.).

This is one of the vast number of compounds proposed in the last few years as substitutes for iodoform. The iodine of iodol is apparently less easily split off the molecule than that of iodoform, and it is said to be less liable to produce poisoning. Iodol contains about 88.57 per cent. of iodine.

Allied Compounds

Antiseptol - Cinchonine Iodosulphate.- Origin. - It is prepared by mixing an aqueous solution of cinchonine sulphate with an aqueous solution of iodine and potassium iodide, and washing and drying the resulting precipitate.

Description and Properties. - It occurs as a light reddish-brown powder, insoluble in water, but soluble in alcohol and chloroform. It contains about 50 per cent. of iodine.

Dose. - 1-3 grains (0.06-0.2 Gm.).

Aristol - Dithymol Diiodide. - Origin. - It is obtained by adding a solution of iodated iodide of potassium to an aqueous solution of hydrate of sodium containing thymol. The resulting precipitate is washed and subsequently dried at ordinary temperature.

Description and Properties. - A dark, brownish-red, amorphous, almost tasteless powder, of a slight, peculiar, iodine-like odor, insoluble in water and glycerin, sparingly soluble in alcohol, but readily soluble in ether, collodion, and chloroform. It is also taken up by fixed oils, petrolatum, etc.

Aristol is decomposed by heat and light, and it should be kept in dark amber-colored, well-stoppered bottles. It contains 45.8 per cent. of iodine.

Dose. - It is not given internally.

Europhen. - Prepared in a manner analogous to that of preparing aristol, expect that isobutylorthocresol is used in place of thymol.

Description and Properties. - An amorphous, yellow powder, having an odor resembling saffron; soluble in ether, chloroform, and fixed oils; insoluble in water and glycerin. It is permanent in dry air, but when moistened with water resolves into iodine, forming a new soluble iodine compound. When heated to 110 C. (2300 F.) it melts, forming a clear brown liquid. It contains 27.6 per cent. of iodine.

Dose. - 1/4-1 1/2 grains (0.016-0.09 Gm.). It is used hypodermically in olive oil,and externally in the form of an ointment, in strengths varying from 3 to 10 per cent.

Antagonists and Incompatibles. - It is incompatible with the preparations of mercury and zinc, with metallic oxides, and with starch.

Losophan. - Origin. - Prepared by slowly adding an aqueous solution of iodine and iodide of potassium to an aqueous solution of ortho-oxyparatoluic acid and sodium bicarbonate. The precipitate formed is washed with water and recrystallized from alcohol.

Description and Properties. - It occurs as colorless, odorless, needle-shaped crystals. Insoluble in water and alcohol, but readily soluble in ether, benzene, chloroform, and fixed oils. It contains 78.39 per cent. of iodine.

Dose. - It is used externally.

Sozoiodol. - Origin. - A combination of iodine 54 per cent., carbolic acid 20 per cent., and sulphur 7 per cent.

Description and Properties. - The sodium, potassium, ammonium, mercury, lead, and zinc salts of this acid are the preparations used, the sodium salt being the one most commonly employed. The sodium sozoiodolate occurs in bright, prismatic, needle-shaped crystals. Soluble in water, alcohol, and glycerin.

Dose. - For external use, in strengths varying from 3 to 20 per cent.

Sulphaminol. Origin. - It is formed by the action of sulphur on the salts of metaoxydiphenylamine.

Description and Properties. - It is a yellow powder, insoluble in water, readily soluble in alkalies, alcohol, and glacial acetic acid.

Dose. - 1 to 4 grains (0.006-0.25 Gm.).

Other compounds of iodine used for much the same purposes are: latrol, aniline iodine, an antiseptic powder; imidiol, a substitute for iodoform; iodoanisol, a rubefacient and antiseptic; iodocasein, a yellow powder with faint iodine odor; iodocrol, carvol and potassium iodide and soda; odorless substitute for iodoform; iodoformal, with odor like vanilla, also an iodoform substitute; iodoformogen, albumin and iodoform; iodogallicin, bismuth iodide and gallicin, antiseptic; iodoterpin, iodin and terpin, dark-brown liquid, substitute for tincture of iodine or iodoform; iodothymoform, an iodized thymol-formaldehyd preparation, a yellow powder rich in iodine. Nosophen, antinosine, eudoxine, are iodine compounds of phenolphthalein. Loretin and vioform,. compounds of cresol and iodine. Airol, a 20 per cent. iodine compound with bismuth and gallic acid.

Antagonists and Incompatibles. - Iodoform is incompatible with mercuric chloride.

Physiological Action. - Externally and Locally. - Iodoform ordinarily possesses no irritating action when applied to the skin or mucous membranes, or to ulcers and wounds. On the contrary, it possesses analgesic properties. It has a tendency to check serous oozing when applied to wounds. It has a limited action in hindering the growth of bacteria when in alkaline serum, but as a dry powder it seems to possess little bactericidal action.

Internally. - Digestive System. - Small doses, if they have any effect, slighly increase the appetite, and tend to increase the salivary, biliary, and intestinal secretions. Large doses disturb the stomach, and may occasion nausea, vomiting, and diarrhea.

Circulatory System.- Small doses retard and strengthen the pulse, and, for a brief period only, increase arterial tension. Full medicinal doses lessen arterial tension and render the pulse slower and weaker. Lethal doses rapidly accelerate the pulse, causing it to become irregular; later, the action of the heart is slowed, and finally arrested in diastole, from paralysis of the cardiac muscle.