Ammonium bituminosulfonate or ammonium bituminosulphonate (synonyms of ichthammol, CAS# brand name: Ichthyol) is a product of natural origin obtained in the first step by dry distillation of

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

-rich oil shale (bituminous schists). By sulfonation of the resulting oil (or purified fractions thereof), and subsequent neutralization with ammonia, Ichthammol results as a viscous, water-soluble substance with a characteristic bitumen-like odor. It is used in medicine (sometimes in combination with zinc oxide) as a treatment for different skin diseases, including eczema and psoriasis (see below).

Ointment A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...

s containing 10% or 20% Ichthammol are most common. They are sometimes called "black ointments" or "drawing salves". Ichthammol's dermatological action was promoted by German physician Paul Gerson Unna.

Composition

From elemental analysis, the composition of Ichthammol was calculated to be C₂₈H₃₆S₅O₆(NH₄)₂. However, as a product of natural origin, it is a mixture of many different compounds. Chemically, it is a

sulfonated Aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution. Aryl sulfonic acids are used as detergents, dye, and drugs. Stoichiomet ...

shale oil that is incompatible with acids, alkali carbonates or hydrates and alkaloidal salts. It is a thick reddish brown liquid, possessing a bituminous odor and taste. It is soluble in water and miscible with glycerin, but is nearly insoluble in strong alcohol or concentrated ether. It contains a large percentage of organically combined

Differentiation from Chinese Materials

Materials made in China (Pinyin transcription: yushizhi and yushizhi ruangao) and offered outside China as Ichthammol or Ammonium Bituminosulfonate do not meet the requirements for this substance in the United States Pharmacopoeia (USP) or European Pharmacopoeia (Ph.Eur). Also, there is no conformity with the definition as connected to CAS# 8029-68-3. The Chinese material is derived from vegetable oils (e.g., soybean oil) instead of bituminous schists as required (Chinese definition according to ChP 10: "Ichthammol is a mixture obtained by sulfuration of vegetable oils (soybean oil, tung oil, corn oil, etc.), sulfonation, and neutralization with ammonia"). As a result, its chemical basis is totally different from the one of Ichthammol USP/Ph.Eur./CAS# 8029-68-3. The characteristic bitumen-like odor (originating from the bituminous source material) is missing with Chinese material.

Usage

Human

Bituminosulfonates are classified as local therapeutic agents with very good tolerability. Pharmacologically, ichthammol has anti-inflammatory,

bactericidal A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their ...

, and

fungicidal Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, ...

properties. It is used to treat a variety of skin disorders as e.g. eczema, psoriasis, Acne rosacea and acne, and it decreases microorganisms in the area surrounding a skin condition. It is commonly used in 10% or 20% concentrate

ointment A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...

, applied topically. Ichthammol ointments, commonly known as ''black ointment'' or ''drawing salve'', should not be confused with black salve, a escharotic (corrosive) paste intended to destroy skin tissue. In contrast, ichthammol does not have any corrosive properties on the skin. In otology, a mixture of glycerol and ichthammol (G & I) is used for the topical treatment of ear infections. It is effective against Gram-positive bacteria. The anti-inflammatory action is explained by its influence on the formation, secretion, and effect of inflammation mediators. Ichthammol is available in pharmacies for compounding medications. Different sources of information exist for exemplary formulations (creams, shake lotions, suppositories, etc.). According to the "list of preferred Specials" by the British Association of Dermatologists (BAD) Ichthammol can be used in dermatology prescribing to treat acutely inflamed atopic eczema, among others. A corresponding recommendation exists for bituminosulfonates in Germany. According to “guideline atopic eczema” bituminosulfonates can be considered for treatment of atopic eczema based on general clinic experience. In the European Dermatology Forum (EDF) guidelines for treatment of atopic eczema Ichthammol is recommended as a useful addition to the basic treatment regimen, especially in mild disease or if TCS treatment is not possible from a patient’s perspective, e.g. corticophobia (steroid phobia).

Veterinary

The

European Medicines Agency The European Medicines Agency (EMA) is an agency of the European Union (EU) in charge of the evaluation and supervision of medicinal products. Prior to 2004, it was known as the European Agency for the Evaluation of Medicinal Products or Euro ...

published a summary report on ichthyol-substances (synonym: bituminosulfonates) during the course of the European Maximum Residue Limits (MRL) procedure in veterinary medicine. The Committee for Medicinal Products for Veterinary Use (CVMP) decided that due to good tolerance and safety, there is no need to establish an MRL for ichthyol-substances. As a result, ichthyol-substances can be applied topically in all mammalian food-producing species without restriction.

References

External sources

* * * {{Ammonium salts Ammonium compounds Organosulfur compounds