Selenium disulfide

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Selenium disulfide
Clinical data
Trade names Selseb, Selsun Blue, others
AHFS/Drugs.com Monograph
Pregnancy
category
  • US: C (Risk not ruled out)
ATC code
Identifiers
Synonyms Selenium sulfide
CAS Number
PubChem CID
ChEMBL
Chemical and physical data
Formula S2Se
Molar mass 143.09
Density 3 g/cm3
Melting point 111 °C (232 °F)
Boiling point 118 to 119 °C (244 to 246 °F) (decomposes)
Solubility in water negligible mg/mL (20 °C)

Selenium disulfide is a medication used to treat pityriasis versicolor and seborrhoeic dermatitis (dandruff).[1] It is applied to the affected area as a lotion or shampoo.[2] Dandruff frequently returns if treatment is stopped.[3]

Side effects include hair loss, irritation of the skin, weakness, and feeling tired.[1] Use in not recommended in children less than 2–5 years old.[3][1] Use in pregnancy or breastfeeding has not been studied.[4] Selenium disulfide is an inorganic compound with the chemical formula SeS2.[5]

Selenium disulfide was approved for medical use in the United States at least as early as 1951.[3] It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.[6] Selenium disulfide is avaliable as a generic medication and over the counter.[2] In the United States a month of treatment costs less than 25 USD.[2] In the United Kingdom 100 ml of 2.5% shampoo costs the NHS about 1.96 pounds.[7]

Medical uses[edit]

Selenium disulfide is sold as an antifungal agent in shampoos for the treatment of dandruff and seborrheic dermatitis associated in the scalp with Malassezia genus fungi.[8][9][10] In the United States, a 1% strength is available over-the-counter, and a 2.5% strength is also available with a prescription. At the 2.5% strength, selenium disulfide is also used on the body to treat tinea versicolor, a type of fungal skin infection caused by a different species of Malassezia.

Side effects[edit]

Selenium disulfide can cause discoloration of the hair and alter the color of hair dyes. It may also discolor metallic jewellery. Selenium monosulfide (SeS) is the only selenium compound so far identified as a carcinogen in animals.[11]

Chemical composition[edit]

Structure of 1,2,3-Se3S5, illustrative of selenium sulfide.

Selenium disulfide has a composition that approximates to SeS2 and is sometimes called selenium sulfide. However, as used in proprietary formulations, it is not a pure chemical compound but a mixture where the overall Se:S ratio is 1:2. The compounds are Se–S rings containing a variable number of S and Se atoms, SenS8−n.[12]

Many selenium sulfides are known as indicated by 77Se-NMR spectroscopy.[13]

History[edit]

Selenium monosulfide, along with elemental selenium and sulfur, has been used in medicinal preparations in the past,[14] causing confusion and contradiction[15] as to exactly what form selenium is in any given topical preparation.[16]

See also[edit]

References[edit]

  1. ^ a b c WHO Model Formulary 2008 (PDF). World Health Organization. 2009. p. 297. ISBN 9789241547659. Retrieved 8 December 2016. 
  2. ^ a b c Hamilton, Richart (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 194. ISBN 9781284057560. 
  3. ^ a b c "Selenium Sulfide". The American Society of Health-System Pharmacists. Retrieved 8 January 2017. 
  4. ^ "Selenium sulfide topical Use During Pregnancy | Drugs.com". www.drugs.com. Retrieved 13 January 2017. 
  5. ^ Mitchell, Stephen C. (2003). Biological Interactions Of Sulfur Compounds. CRC Press. p. 174. ISBN 9780203362525. 
  6. ^ "WHO Model List of Essential Medicines (19th List)" (PDF). World Health Organization. April 2015. Retrieved 8 December 2016. 
  7. ^ British national formulary : BNF 69 (69 ed.). British Medical Association. 2015. p. 829. ISBN 9780857111562. 
  8. ^ Selenium(IV) sulfide - pharmacy codes search engine
  9. ^ Chemicals of Selenium .Se
  10. ^ Accessed Dec. 24, 2007
  11. ^ "selenium compounds". 
  12. ^ Cyclic selenium sulfides R. Steudel, R. Laitinen, Topics in Current Chemistry, (1982), 102, 177-197
  13. ^ Pekonen, Pentti.; Hiltunen, Yrjō; Laitinen, Risto S.; Pakkanen, Tapani A. (1991). "Chalcogen ring interconversion pathways. 77Se NMR spectroscopic study of the decomposition of 1,2,3,4,5-Se5S2 to 1,2,3,4,5,6-Se6S2 and 1,2,3,4-Se4S2". Inorganic Chemistry. 30 (19): 3679. doi:10.1021/ic00019a022. 
  14. ^ "Definition: selenium sulfide from Online Medical Dictionary". 
  15. ^ "DrugBank: DB00971 (Selenium Sulfide)". 
  16. ^ "selenium sulfide: Definition and Much More from Answers.com". 

Further reading[edit]