Iodoform

Absorption

Iodoform is reported to be absorbed through denuded skin, wounds or mucous membranes [L2646].

Toxicity

Systemic intoxication and severe poisoning, mostly characterized by dermatitis, headache, somnolence, delirium, hallucinations, consciousness disturbances, coma, vomiting, CNS depression, tachycardia, and rapid feeble pulse, may result from excess absorption through wounds and abscesses, or ingestion of large quantities [L2646]. While there is no known antidote for iodoform overdose, supportive and symptomatic treatment is highly recommended [L2646].
Hepatocellular damage has been observed with iodoform toxicity, where production of both fatty liver and necrosis was seen, as well as lesions of liver membranous cellular components [L2646]. Iodoform induces hepatocellular injury and hepatic lesions in a similar manner to carbon tetrachloride, where cellular membranes may possibly be primary sites of action .

Description

Iodoform is a stable, pale yellow crystalline solid. It is volatile with a characteristic pungent, unpleasant and penetrating odour, but with a sweetish taste. It is incompatible with strong oxidising agents, reducing agents, lithium, and metallic salts such as mercuric oxide, silver nitrate, strong bases, calomel, and tannin. Reports indicate that earlier iodoform was in use as a disinfectant and as an antiseptic or dressing and healing of wounds and sores for pets. Iodoform is the active ingredient in many antiseptic or dressing powders used for dogs and cats to prevent infection.

Chemical properties

yellow solid with a characteristic pungent and

Chemical properties

Iodoform is a yellow or greenish-yellow powder or crystalline solid that is volatile with steam and contains 96.69% iodine. It has a very characteristic pungent odor. An odor threshold of 0.005 ppm has been reported.

The Uses of Iodoform

Iodoform has limited use as a chemical intermediate and for medicinal purposes as disinfectant and antiseptic and has been used in veterinary medicine.

The Uses of Iodoform

Triiodomethane is a crystalline compound commonly used as a disinfectant. It can be used in the process of removing heavy metals such as mercury from fuids.

The Uses of Iodoform

It is used as a topical anti-infective, applied to the skin.

Background

Iodoform is an organoiodine compound with the formula CHI3 and a tetrahedral molecular geometry. It is a relatively water-insoluble yellow solid that is chemically reactive in free-radical reactions . Due to its antimicrobial properties following topical administration, minimal levels of iodoform may be found in disinfectants and it is more primarily used for veterinary purposes. Iodoform has also been found in dental paste and root canal filling materials in combination with other intracanal medications due to its radiopacity . Since the beginning of the 20th century, iodoform has been commonly used as a healing and antiseptic dressing or powder for wounds and sores, however such clinical use to this date is limited. Iodoform is soluble in fatty acids and decomposes releasing iodine in nascent state (96,7% of iodine) when in contact with secretions or endodontic infections .

Indications

No approved therapeutic indications.

Definition

A yellow crystalline compound made by warming ethanal with an alkaline solution of an iodide:
CH₃CHO + 3I^– + 4OH^– → CHI₃ +
HCOO^– + 3H₂O
The reaction also occurs with all ketones of general formula CH₃COR (R is an alkyl group) and with secondary alcohols CH₃CH(OH)R. Iodoform is used as a test for such reactions (the iodoform reaction).

General Description

Bright yellow or yellow powder or crystals. Penetrating odor. Unctuous touch. Odor threshold 0.4 ppb.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Iodoform decomposes at high temperatures. Decomposes slowly in light at room temperature. Reacts violently with lithium. Is incompatible with mercuric oxide, calomel, silver nitrate, tannin, and balsam Peru. Is also incompatible with strong bases, strong oxidizing agents and magnesium. Vigorous reactions occur with acetone in the presence of solid potassium hydroxide or calcium hydroxide, hexamethylenetetramine at 352° F, mercury(I) fluoride and finely divided reduced silver.

Hazard

Irritant. Decomposes violently at 400F (204C).

Health Hazard

Iodoform causes central nervous system depression and damage to the kidneys, liver, and heart.

Fire Hazard

Literature sources indicate that Iodoform is nonflammable.

Biochem/physiol Actions

Iodoform is an iodine containing compound, which is used in antiseptic applications in the medical and veterinary medicine fields. Iodoform improves fermentation in the biomass ensilage conversion system by improving lactic acid production and inhibiting butyric fermentation.

Pharmacokinetics

Iodoform exhibits antibacterial activities after topical application. In a comparative study of wound dressing agents, iodoform gauze exerted an antibacterial effect 3 hours after the start of bacterial growth of E. coli and subsequently maintained the strong antibacterial effectiveness . A study demonstrated that direct and indirect exposure to high concentrations of iodoform induces a cytotoxic effect on cultures of macrophages and epithelial cells in vitro, while cell proliferation was enhanced at low concentrations of iodoform . This cytotoxic effect of iodoform in root canals may further lead to long-term local irritation to follicles of permanent successors and formation of cyst-like radiolucent defects .

Carcinogenicity

Iodoform has been included in the NCI daily bioassay program. According to their summary: the high and low time-weighted average daily dosages of iodoform were, respectively, 142 and 71 mg/kg for male rats, 55 and 27 mg/kg for female rats, and 93 and 47 mg/kg for male and female mice. A significant positive association between dosage and mortality was observed in male rats but not in female rats or in mice of either sex. Adequate numbers of animals in all groups survived sufficiently long to be at risk from late-developing tumors. No statistical significance could be attributed to the incidences of any neoplasms in rats or mice of either sex when compared to their respective controls. Under the conditions of this bioassay, no convincing evidence was provided for the carcinogenicity of iodoform in Osborne–Mendel rats or B6C3F1 mice.

Metabolism

It is expected to be oxidized to iodine [L2646].

Purification Methods

Crystallise it from MeOH, EtOH or EtOH/EtOAc. It is steam volatile. It is a disinfectant. [Beilstein 1 IV 97.]