Ichthammol or ammonium bituminosulfonate (brand name Ichthyol), also known as black ointment, is a medication derived from sulfur-rich oil shale (bituminous schists). It is used (sometimes in combination with zinc oxide) as a treatment for different skin diseases, including eczema and psoriasis (see below). It is applied on the skin as an ointments, most commonly containing 10% or 20% ichthammol.
Bituminosulfonates are considered topical therapeutic agents with very good tolerability.[1]
Ichthammol ointments, commonly known as black ointment or drawing salve, should not be confused with black salve, an escharotic (corrosive) paste intended to destroy skin tissue.[5] In contrast, ichthammol does not have any corrosive properties on the skin.
Production
Ichthammol is obtained through three steps from bituminous schists: dry distillation, sulfonation of the resulting oil (or purified fractions thereof), and finally neutralization with ammonia.[6]
Properties
Ichthammol is a viscous, water-soluble substance with a characteristic bitumen-like odor.[6] It 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 sulfur.
Chemically speaking ichthammol is a sulfonatedshale oil. From elemental analysis, the composition of ichthammol was calculated to be C28H36S5O6(NH4)2.[7] However, as a product of natural origin, it is a mixture of many different compounds.[8]
Similar materials
Similar substances can be made by altering the starting material. An "ammonium sufobitol" (Tumenol-Ammonium), made from light shale oil of the Messel pit, was sold until 2000 in Germany.[9] The Chinese material labelled as "ichthammol" are actually an ersatz product made from vegetable oil.
Ichtasol (USAN: Ictasol) is produced from the light (as opposed to heavy) fraction of distilled shale oil. It has a pale appearance.[10] There appears to be an oral preparation made from this mixture.[11]
Chinese vegetable oil product
"Ichthammol" (鱼石脂 Yushizhi) made in China does not meet standards for ichthammol as specified in United States Pharmacopoeia (USP), European Pharmacopoeia (Ph.Eur), or for the CAS number. Instead of requiring bituminous schists like these definitions, the Chinese Pharmacopoeia definition for "ichthammol" uses ordinary vegetable oil:
Ichthammol is a mixture obtained by sulfurization of vegetable oils (soybean oil, tung oil, corn oil, etc.), sulfonation, and neutralization with ammonia. Organic sulfur content ≥ 5.5%, ammonium content ≥ 2.5%. — Chinese definition according to ChP 10[12]
As a result, Chinese "ichthammol" is very different from standard ichthammol. The characteristic bitumen-like odor (originating from the bituminous source material) is missing with Chinese material.[13]
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.[16] 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.[17] 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).[18]
Ear infections
In otology, a mixture of glycerol and ichthammol (G & I) is used for the topical treatment of ear infections.[19] 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.[20][21]
Availability
Ichthammol is available in pharmacies for compounding medications. Different sources of information exist for exemplary formulations (creams, shake lotions, suppositories, etc.).[22][23][24]
The European Medicines Agency published a summary report on ichthyol-substances (synonym: bituminosulfonates) during the course of the European Maximum Residue Limits (MRL) procedure[11] 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.
^Schmid-Wendtner MH, Korting HC, Sterry W (2001). "Bituminosulfonate.". Therapeutische Verfahren in der Dermatologie–Dermatika und Kosmetika. Berlin, Wien: Blackwell Wissenschafts-Verlag. pp. 165–171.
^Paul Gerson Unna: About Ichthyol. In: Monatshefte für praktische Dermatologie, Band XXV, 1897 (in German).
^Bracher F, Heisig P, Langguth P, Mutschler E, Rücker G, Scriba G, Stahl-Biskup E, Troschütz R, eds. (2014). "Ammoniumbituminosulfonat". Kommentar zum Europäischen Arzneibuch, Wissenschaftliche Erläuterungen zum Arzneibuch [Commentary to the Pharmacopoeia Europaea, Scientific explanations of the Pharmacopoeia] (in German). 4. Stuttgart: Wissenschaftliche Verlagsgesellschaft.
^Warnecke J, Wendt A (February 1998). "Anti-inflammatory action of pale sulfonated shale oil (ICHTHYOL pale) in UVB erythema test". Inflammation Research. 47 (2): 75–78. doi:10.1007/s000110050282. PMID9535545. S2CID9014012.
^Buckley DA, Root T and Bath S, Specials Recommended by the British Association of Dermatologists for Skin Disease, Clinical Standards Unit of the British Association of Dermatologists, London, UK, 2014, p. 9 (www.bad.org.uk/specials accessed October 2nd, 2015)
^Werfel T, Aberer W, Ahrens F, Augustin M, Biedermann T, Diepgen T, et al. (January 2016). "[Not Available]". Journal der Deutschen Dermatologischen Gesellschaft. 14 (1): e1-75. doi:10.1111/ddg.12884. PMID26713660. S2CID203739944.
^Masood A, Moumoulidis I, Ray S, Chawla O, Panesar J (August 2008). "A randomised controlled trial comparing Triadcortyl with 10% glycerine-ichthammol in the initial treatment of severe acute otitis externa". European Archives of Oto-Rhino-Laryngology. 265 (8): 881–885. doi:10.1007/s00405-007-0463-1. PMID17922130. S2CID26976193.
^Schewe C, Schewe T, Rohde E, Diezel W, Czarnetzki BM (1994). "Inhibitory effects of sulfonated shale oils (ammonium bituminosulphonates, Ichthyols) on enzymes of polyenoic fatty acid metabolism". Archives of Dermatological Research. 286 (3–4): 137–141. doi:10.1007/bf00374208. PMID7911653. S2CID12647893.
^Altmeyer P (2005). Therapielexikon Dermatologie und Allerlogie (2nd ed.). Berlin: Springer. pp. 1024, 1040, 1051.
^Langley CA, Belcher D (2012). "Suppositories and pessaries". Pharmaceutical Compounding and Dispensing (2nd ed.). London, UK: Pharmaceutical Press. p. 143. ISBN978-0-85711-055-8.
^Gayko G, Cholcha W, Kietzmann M (October 2000). "[Anti-inflammatory, antibacterial and antimycotic effects of dark sulfonated shale oil (ichthammol)]". Berliner und Munchener Tierarztliche Wochenschrift. 113 (10): 368–373. PMID11084753.
Further reading
Cholcha W, Leuschner J, Leuschner F (July 1994). "[The adverse effects of dark sulfonated shale oil following local and systemic administration]". Arzneimittel-Forschung (in German). 44 (7): 844–849. PMID7945520.
Diezel W, Schewe T, Rohde E, Rosenbach T, Czarnetzki BM (December 1992). "[Ammonium bituminosulfonate (Ichthyol). Anti-inflammatory effect and inhibition of the 5-lipoxygenase enzyme]". Der Hautarzt (in German). 43 (12): 772–774. PMID1361926.
Nilssen E, Wormald PJ, Oliver S (April 1996). "Glycerol and ichthammol: medicinal solution or mythical potion?". The Journal of Laryngology and Otology. 110 (4): 319–321. doi:10.1017/s0022215100133547. PMID8733451. S2CID37026367.
