Selenium sulfide 2311327 224622293 2008-07-09T18:19:59Z Arcadian 104523 infobox {{chembox new |ImageFile= |ImageSize= |IUPACName= |OtherNames= |Section1={{Chembox Identifiers | CASNo=7488-56-4 | PubChem=24087 | SMILES=S=[Se]=S | MeSHName=Selenium+sulfide }} |Section2={{Chembox Properties | Formula=S<sub>2</sub>Se | MolarMass=143.09 | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= }} |Section3={{Chembox Hazards | MainHazards= | FlashPt= | Autoignition= }} }} '''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>&minus;</nowiki>S rings containing a variable number of S and Se atoms, Se<sub>n</sub>S<sub>8<nowiki>&minus;</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]]