Selenium sulfide
2311327
224622293
2008-07-09T18:19:59Z
Arcadian
104523
infobox
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|Section1={{Chembox Identifiers
| CASNo=7488-56-4
| PubChem=24087
| SMILES=S=[Se]=S
| MeSHName=Selenium+sulfide
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|Section2={{Chembox Properties
| Formula=S<sub>2</sub>Se
| MolarMass=143.09
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|Section3={{Chembox Hazards
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'''Selenium sulfide''' (also '''selenium sulphide'''; see [[Sulfur#Spelling|spelling]]), a loose name for what is technically selenium '''di'''sulfide or selenium (IV) sulfide, formula '''SeS<sub>2</sub>''' <ref>[http://pharmacycode.com/Selenium(IV)_sulfide.html Selenium(IV) sulfide - pharmacy codes search engine<!-- Bot generated title -->]</ref><ref>[http://www.selenium.se/selenium-disulfide.html Chemicals of Selenium .Se<!-- Bot generated title -->]</ref>, is an [[antifungal]] agent often used in [[shampoo]]s for the treatment of [[dandruff]] and [[seborrheic dermatitis]] associated in the scalp with [[Malassezia]] genus fungi. <ref>[http://dermnetnz.org/treatments/selenium.html Accessed Dec. 24, 2007] </ref> In the [[United States]], a 1% strength is available [[Over-the-counter drug|over-the-counter]], and a 2.5% strength is also available with a [[Medical prescription|prescription]]. At the 2.5% strength, selenium (IV) sulfide is also used on the body to treat [[tinea versicolor]], a type of [[fungal]] skin infection caused by a different species of ''Malassezia''.
It can be used for adults and children over the age of 5. It should be used twice a week for the first two weeks then once a week for the next two weeks.
==Chemical composition==
Selenium sulfide has a composition that approximates to SeS<sub>2</sub> and is sometimes called selenium disulfide. However as used in proprietary formulations it is not a pure chemical compound but is a mixture of chemical compounds where the overall Se:S ratio is 1:2. The compounds are cyclic Se<nowiki>−</nowiki>S rings containing a variable number of S and Se atoms, Se<sub>n</sub>S<sub>8<nowiki>−</nowiki>n</sub>.<ref> Cyclic selenium sulfides R. Steudel, R. Laitinen, Topics in Current Chemistry, (1982), 102, 177-197</ref> The formal oxidation state of +4 can be assigned from the stoichiometry and therefore the mixture is sometimes called selenium(IV) sulfide.<ref>[http://pharmacycode.com/Selenium(IV)_sulfide.html Selenium(IV) sulfide - pharmacy codes search engine<!-- Bot generated title -->]</ref><ref>[http://www.selenium.se/selenium-disulfide.html Chemicals of Selenium .Se<!-- Bot generated title -->]</ref>,
Selenium sulfide can cause discoloration of the [[hair]] and alter the color of [[hair dyes]]. It may also discolor [[metal]]lic [[jewellery]]. It should not be used in the first 3 months of [[pregnancy]].
==Confusion with selenium(II) sulfide (selenium monosulfide), a carcinogen==
Selenium monosulfide (SeS) is the only selenium compound so far identified as a carcinogen in animals. <ref>http://www.scorecard.org/chemical-profiles/html/selenium.html</ref> Selenium monosulfide, along with elemental selenium and sulfur has been used in medicinal preparations in the past <ref>[http://cancerweb.ncl.ac.uk/cgi-bin/omd?selenium+sulfide Definition: selenium sulfide from Online Medical Dictionary<!-- Bot generated title -->]</ref>, causing confusion and contradiction <ref>[http://redpoll.pharmacy.ualberta.ca/drugbank/cgi-bin/getCard.cgi?CARD=APRD01323.txt DrugBank: DB00971 (Selenium Sulfide)<!-- Bot generated title -->]</ref> as to exactly what form selenium is in, in any given topical preparation.<ref>[http://www.answers.com/topic/selenium-sulfide?cat=health selenium sulfide: Definition and Much More from Answers.com<!-- Bot generated title -->]</ref>
==See also==
* [[Zinc pyrithione]], an [[antimicrobial agent]] used in some medicated shampoos, which can be used by all patients of any age. It should be used daily until the dandruff has gone.
==Footnotes==
{{reflist|2}}
{{antimicrobial-stub}}
{{Antifungals}}
[[Category:Antifungals]]
[[Category:Cosmetic chemicals]]
[[Category:Selenium compounds]]
[[Category:Sulfides]]
[[de:Selen(IV)-sulfid]]
[[fr:Sulfure de sélénium]]